Condition
Sleep Quality
Sleep quality reflects how easily you fall asleep, how well you stay asleep, and how rested you feel, all guided by the brain's body clock and calming signals such as GABA. Tryptophan has the most support: trials found people fell asleep sooner, especially those with mild insomnia, while small studies of the peptide DSIP found total sleep time went up. Still, evidence beyond tryptophan is limited, and studies were small or mostly animal work.
Sources: PMID 16539679; PMID 6145137
- Updated
- How we grade
- 100 studies cited
- Supplements studied
- 4
- Medicines and peptides
- 3
- Graded outcomes
- 13
Evidence by supplement
- Strong
- Moderate
- Limited
- Very limited
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Sleep Latency Doses ≥1g decrease sleep latency; best results in mild insomnia | Improves (the measure goes down) | Moderate effect | 800 people | |||
| Subjective Sleepiness Increased rated subjective sleepiness at doses ≥1g | Improves (the measure goes up) | Moderate effect | 400 people |
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Sleep Quality Small Improvement (chamomile extract studies) | Improves (the measure goes up) | Small effect | 120 people | |||
| Daytime Functioning Trend toward improvement, not statistically significant | Improves (the measure goes up) | Small effect | 34 people |
Magnolia Bark (Magnolia officinalis)
- Sleep Quality: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Sleep Quality Preclinical: Honokiol (10-20 mg/kg) shortened sleep latency to NREM sleep and increased NREM sleep amount by modulating GABAA benzodiazepine site. Clinical evidence limited but mechanism supports sleep promotion without next-day sedation. | Improves (the measure goes up) | Moderate effect |
GABA
- Sleep Latency: improves
- Non-REM Sleep Duration: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Sleep Latency Moderate Decrease - 100mg GABA reduced time to fall asleep | Improves (the measure goes down) | Moderate effect | 120 people | |||
| Non-REM Sleep Duration Small Increase in non-REM sleep duration | Improves (the measure goes up) | Small effect | 60 people |
Prescription medicines and peptides studied, for context
CJC-1295
- Slow-Wave Sleep Duration: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Slow-Wave Sleep Duration Enhanced deep sleep duration (GHRH analog data) | Improves (the measure goes up) | Moderate effect | 17 studies | 35 people |
DSIP (Delta Sleep-Inducing Peptide)
- Sleep Onset Latency: improves
- Total Sleep Time: improves
- Delta Wave Activity: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Sleep Onset Latency Moderate Decrease | Improves (the measure goes down) | Moderate effect | 12 studies | 85 people | ||
| Total Sleep Time Moderate Increase | Improves (the measure goes up) | Moderate effect | 12 studies | 92 people | ||
| Delta Wave Activity Moderate Increase | Improves (the measure goes up) | Moderate effect | 1 study | 45 people |
Epitalon
- Melatonin Production: improves
- Sleep Architecture: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Melatonin Production Moderate increase in nocturnal melatonin | Improves (the measure goes up) | Moderate effect | 5 studies | 78 people | ||
| Sleep Architecture Small improvement in sleep quality | Improves (the measure goes up) | Small effect | 2 studies | 42 people |
What the published studies found
19 automated readings
Ashwagandha: sleep quality
The best available review (2026, 24 studies) found an improvement in sleep quality. That review studied healthy individuals and patients with stress-related or functional disorders. All 9 studies read agree. The evidence is moderate.
9 studies counted of 11 read: 3 reviews and 6 trials (547 people in the trials).
- Systematic review, 2026; 24 studies; healthy individuals and patients with stress-related or functional disorders: improves (the review the verdict rests on).
improved sleep quality, enhancement of cognitive functions
Clinical evidence for the adaptogenic effects of Withania somnifera and Rhodiola rosea - A systematic review with molecular interpretation of psychometric outcomes - Meta-analysis, 2024; 5 studies, 254 people; patients with anxiety and/or insomnia: improves. Safety and efficacy of Withania somnifera for anxiety and insomnia: Systematic review and meta-analysis
- Meta-analysis, 2021; 5 studies, 400 people; adults 18 years old and above: improves.
significant effect on overall sleep (Standardized Mean Difference -0.59
Effect of Ashwagandha (Withania somnifera) extract on sleep: A systematic review and meta-analysis - Randomised trial, 2026; 135 people: improves.
Sleep quality, psychological well-being, and eating behavior significantly improved from baseline to day 60 in …
Efficacy and safety of Ashwagandha root extract sustained-release (AshwaSR) capsules in healthy adult, stressed subjects: A randomized, double-blind, placebo-controlled, parallel-group, 3-arm clinical trial - Randomised trial, 2026; 66 people; postmenopausal women aged 45-65 years: improves.
significantly greater improvements in sleep quality
Effects of Withania somnifera root extract on sleep quality, body composition, and menopausal symptoms in postmenopausal women: a randomized, double-blind, placebo-controlled trial - Randomised trial, 2025; 90 people: improves.
improvements in PSS, BAI, and PSQI scores
A New Ashwagandha Formulation (Zenroot™) Alleviates Stress and Anxiety Symptoms While Improving Mood and Sleep Quality: A Randomized, Double-Blind, Placebo-Controlled Clinical Study - Randomised trial, 2024; 52 people; healthy adults with sleep problems: improves.
Changes in the visual analogue scale (VAS) for sleep quality were significantly higher in the …
Effectiveness of Enriched Milk with Ashwagandha Extract and Tryptophan for Improving Subjective Sleep Quality in Adults with Sleep Problems: A Randomized Double-Blind Controlled Trial - Randomised trial, 2022; 60 people; healthy college students: improves.
group membership affected final sleep (58.4 ± 12.4 vs. 48.2 ± 15.0
The Impact of Ashwagandha on Stress, Sleep Quality, and Food Cravings in College Students: Quantitative Analysis of a Double-Blind Randomized Control Trial - Randomised trial, 2020; 144 people; healthy adults with non-restorative sleep: improves.
72% increase in self-reported sleep quality
A randomized, double blind, placebo controlled study to evaluate the effects of ashwagandha (Withania somnifera) extract on sleep quality in healthy adults
- Systematic review, 2026; 24 studies; healthy individuals and patients with stress-related or functional disorders: improves (the review the verdict rests on).
Coenzyme Q10: sleep quality
Mixed or unclear: two readings of the studies disagreed. One reading found evidence too weak to tell for sleep quality, the other an improvement. The question is open.
1 study counted of 7 read: 1 trial (50 people in the trials).
- Randomised trial, 2025; 50 people; patients with tinnitus due to presbycusis: improves.
sleep disorder (-7.60 ± 1.38) and (-1.0 ± 8.55)
The Effect of Coenzyme Q10 on Tinnitus Severity and Sleep Quality in Patients with Presbycusis
- Randomised trial, 2025; 50 people; patients with tinnitus due to presbycusis: improves.
Creatine: sleep quality
The studies read are too weak to tell whether Creatine changes sleep quality. The evidence is very weak.
5 studies counted of 9 read: 4 trials (93 people in the trials).
- Crossover trial, 2026; 58 people; healthy and active adults: mixed results.
Some positive and potentially undesirable effects were observed in sleep quality assessments
Effects of six weeks of guanidinoacetic acid supplementation with and without creatine monohydrate on cognitive function and markers of health in healthy adults - Study, 2026; tactical populations (e.g. military, law enforcement): improves. The emerging and evolving evidence supporting creatine as an ergogenic aid: history and applications
- Crossover trial, 2025; 14 people; physically active men: improves.
CrM improved sleep quality compared to PL
Effects of Creatine Monohydrate Loading on Sleep Metrics, Physical Performance, Cognitive Function, and Recovery in Physically Active Men: A Randomized, Double-Blind, Placebo-Controlled, Crossover Trial - Randomised trial, 2024; 21 people; naturally menstruating females: no clear difference. Creatine Improves Total Sleep Duration Following Resistance Training Days versus Non-Resistance Training Days among Naturally Menstruating Females
- Randomised trial, 2013: no clear difference.
no general changes were observed in
Creatine supplementation in fibromyalgia: a randomized, double-blind, placebo-controlled trial
- Crossover trial, 2026; 58 people; healthy and active adults: mixed results.
Ginkgo Biloba: sleep quality
The 1 study read (398 people in all) mostly found an improvement in sleep quality. The evidence is limited.
1 study counted of 11 read: 1 trial (398 people in the trials).
- Randomised trial, 2026; 398 people; children aged 5-14 with monosymptomatic nocturnal enuresis: improves. Ginkgo biloba versus desmopressin in treatment of children with monosymptomatic nocturnal enuresis: A randomized controlled trial
Glycine: sleep quality
The studies read are too weak to tell whether Glycine changes sleep quality. They lean toward an improvement, which is not enough to claim one. The evidence is very weak.
1 study counted of 9 read: 1 trial (20 people in the trials).
- Crossover trial, 2021; 20 people; urology outpatients with overactive bladder symptoms: improves.
sleep latency, latency to first nighttime urination
Dietary glycine improves urine storage symptoms in urology outpatients
- Crossover trial, 2021; 20 people; urology outpatients with overactive bladder symptoms: improves.
Inositol: sleep quality
The studies read are too weak to tell whether Inositol changes sleep quality. They lean toward an improvement, which is not enough to claim one. The evidence is very weak.
1 study counted of 4 read: 1 trial (60 people in the trials).
- Randomised trial, 2022; 60 people; pregnant women with low-risk singleton pregnancies: improves.
mean difference of the total sleep quality score between the two groups was -1.537
The impact of myo-inositol supplementation on sleep quality in pregnant women: a randomized, double-blind, placebo-controlled study
- Randomised trial, 2022; 60 people; pregnant women with low-risk singleton pregnancies: improves.
Lavender: sleep quality
The studies disagree. A Cochrane review (2020, 13 studies, 708 people) found little or no difference in sleep quality, while 10 of the 11 studies read found an improvement. The evidence is very weak.
11 studies counted of 11 read: 8 reviews and 3 trials (153 people in the trials).
- Meta-analysis, 2020; 13 studies, 708 people; people with dementia in institutional care: no clear difference (the review the verdict rests on).
We did not find evidence of benefit on these outcomes.
Aromatherapy for dementia - Meta-analysis, 2025; 11 studies, 628 people: improves.
sleep-enhancing effect of lavender essential oil intervention in adults was significant
The Sleep-Enhancing Effect of Lavender Essential Oil in Adults: A Systematic Review and Meta-Analysis - Meta-analysis, 2025; 9 studies; older adults with sleep disorders: improves.
significant improvement in the total score of sleep quality
A systematic review and meta-analysis of clinical trials on lavender for sleep disorders in older adults - Meta-analysis, 2023; 3 studies; postpartum mothers: improves.
sleep quality in the group receiving lavender improved
The effect of lavender on mothers sleep quality in the postpartum period: a systematic review and meta-analysis - Systematic review, 2022; 13 studies, 838 people; patients with cancer: improves.
lavender was significantly effective in the reduction of anxiety and pain, and improved sleep quality
A systematic review of the effect of lavender on cancer complications - Systematic review, 2022; 20 studies; adults without insomnia: improves.
Lavender essential oil was associated with improved sleep quality
The Effect of Lavender on Sleep Quality in Individuals Without Insomnia: A Systematic Review - Meta-analysis, 2022; 4 studies; prenatal and postnatal women: improves.
produced a 0.98-point improvement in postnatal mothers' quality of sleep
[Fatigue relief by aromatherapy use in prenatal and postnatal women: a systematic review and meta-analysis] - Systematic review, 2019; 3 studies; menopausal and elderly women: improves. Effect of Lavender on Sleep, Sexual Desire, Vasomotor, Psychological and Physical Symptom among Menopausal and Elderly Women: A Systematic Review
- Randomised trial, 2026; 90 people; elderly individuals: improves.
PSQI total score was 6.11±2.86 in the pre-test and 4.33±2.07 in the post-test
The effect of lavender scent recommended to the elderly on sleep quality and physical balance: A randomized controlled trial - Randomised trial, 2024; 54 people: improves.
Sleep quality scores significantly increased (p = <0.001)
The effect of lavender and bergamot oil applied via inhalation on the anxiety level and sleep quality of surgical intensive care unit patients - Randomised trial, 2021; 9 people: improves.
All participants reported better sleep quality
A pilot study on essential oil aroma stimulation for enhancing slow-wave EEG in sleeping brain
- Meta-analysis, 2020; 13 studies, 708 people; people with dementia in institutional care: no clear difference (the review the verdict rests on).
Lemon Balm: sleep quality
The best available review (2024) found an improvement in sleep quality. That review studied people with psychological well-being concerns. 2 of the 3 studies read agree; 1 found no clear difference. The evidence is limited.
3 studies counted of 11 read: 1 review and 2 trials (44 people in the trials).
- Systematic review, 2024; people with psychological well-being concerns: improves (the review the verdict rests on).
can elicit cognitive and sleep-quality enhancement
Clinical Efficacy and Tolerability of Lemon Balm (Melissa officinalis L.) in Psychological Well-Being: A Review - Crossover trial, 2024: improves.
significant reduction in the ISI score in the treated group
Effects of Melissa officinalis Phytosome on Sleep Quality: Results of a Prospective, Double-Blind, Placebo-Controlled, and Cross-Over Study - Randomised trial, 2023; 44 people; type 2 diabetes patients with depression: no clear difference.
no significant differences were observed in
The effects of melissa officinalis on depression and anxiety in type 2 diabetes patients with depression: a randomized double-blinded placebo-controlled clinical trial
- Systematic review, 2024; people with psychological well-being concerns: improves (the review the verdict rests on).
Magnesium: sleep quality
The studies disagree. The best available review (2026, 12 studies) found little or no difference in sleep quality, while 4 of the 5 studies read found an improvement. The evidence is very weak.
5 studies counted of 10 read: 3 reviews and 2 trials (155 people in the trials).
- Systematic review, 2026; 12 studies; adults with sleep-related outcomes: no clear difference (the review the verdict rests on).
Findings were inconsistent across subjective outcomes
Magnesium Supplementation for Sleep in Adults: A Systematic Review of Randomized Controlled Trials - Systematic review, 2024; 15 studies; patients with anxiety or sleep disorders: improves.
Five out of eight sleep-related studies reported improvements in sleep parameters
Examining the Effects of Supplemental Magnesium on Self-Reported Anxiety and Sleep Quality: A Systematic Review - Meta-analysis, 2021; 3 studies, 151 people; older adults with insomnia: improves.
sleep onset latency time was 17.36 min less
Oral magnesium supplementation for insomnia in older adults: a Systematic Review & Meta-Analysis - Randomised trial, 2024; 80 people; adults with self-reported sleep problems: improves.
MgT significantly (p < 0.05) improved vs placebo deep sleep score
Magnesium-L-threonate improves sleep quality and daytime functioning in adults with self-reported sleep problems: A randomized controlled trial - Randomised trial, 2022; 75 people; patients with restless legs syndrome: improves. Therapeutic effects of magnesium and vitamin B6 in alleviating the symptoms of restless legs syndrome: a randomized controlled clinical trial
- Systematic review, 2026; 12 studies; adults with sleep-related outcomes: no clear difference (the review the verdict rests on).
Melatonin: sleep quality
The studies disagree. A Cochrane review (2018, 4 studies, 151 people) did not settle it for sleep quality, while 3 of the 8 studies read found an improvement. The evidence is very weak.
8 studies counted of 11 read: 7 reviews and 1 trial (57 people in the trials).
- Systematic review, 2018; 4 studies, 151 people; adults in the intensive care unit: unclear: evidence too weak to tell (the review the verdict rests on). Melatonin for the promotion of sleep in adults in the intensive care unit
- Systematic review, 2026; 98 studies, 28,920 people; individuals with chronic non-cancer pain: improves.
melatonin significantly improved sleep quality compared with placebo
Comparative effectiveness and safety of pharmacological interventions for sleep outcomes in chronic non-cancer pain: a systematic review and network meta-analysis - Meta-analysis, 2026; 23 studies, 2,028 people; people with chronic or postoperative musculoskeletal pain: mixed results.
Sleep quality favoured melatonin in people with chronic MSK pain
Efficacy and effectiveness of melatonin for the management of musculoskeletal pain: a systematic review and meta-analysis of placebo and active controlled trials - Systematic review, 2026; 23 studies, 1,941 people; adults with migraine and sleep disturbances: no clear difference. Interventions for Migraine and Sleep: A Systematic Review Exploring Their Bidirectional Association
- Systematic review, 2026; 7 studies, 497 people; menopausal women: no clear difference. A systematic review and meta-analysis of randomized controlled trials investigated the effects of melatonin supplementation on bone mineral density, quality of life, and sleep in menopausal women
- Meta-analysis, 2026; 4 studies, 455 people; patients undergoing total joint arthroplasty: no clear difference.
melatonin did not significantly impact subjective or objective sleep outcomes
Evaluating Whether Melatonin Impacts Postoperative Sleep Following Total Joint Arthroplasty: A Systematic Review and Meta-analysis of Randomized Controlled Trials - Meta-analysis, 2026; 7 studies, 409 people: improves. The Effectiveness of Melatonin for Sleep Disturbances in Parkinson' Disease: Systematic Review and Meta-Analysis
- Randomised trial, 2026; 57 people; patients undergoing urological surgery: improves.
sleep-quality scores increased significantly in the melatonin group
The effect of preoperative melatonin patches on sleep quality in patients undergoing urological surgery
Omega-3 Fatty Acids: sleep quality
The studies disagree. The best available review (2024, 8 studies) found an improvement in sleep quality, while 3 of the 8 studies read found no clear difference. The evidence is very weak.
8 studies counted of 11 read: 4 reviews and 4 trials (202 people in the trials).
- Meta-analysis, 2024; 8 studies: improves (the review the verdict rests on).
Subjectively assessed sleep was significantly improved by omega-3 LC-PUFA
Effect of omega-3 fatty acids on sleep: a systematic review and meta-analysis of randomized controlled trials - Systematic review, 2023; 9 studies; postmenopausal women: no clear difference.
sleep quality outcomes displayed heterogeneity across the studies
Effects of Omega-3 Polyunsaturated Fatty Acids Intake on Vasomotor Symptoms, Sleep Quality and Depression in Postmenopausal Women: A Systematic Review - Meta-analysis, 2021; 20 studies; infants, children, and adults: no clear difference.
No effectiveness was found in adults' total sleep duration, sleep latency, sleep efficiency, sleep quality
Omega-3 long-chain polyunsaturated fatty acid and sleep: a systematic review and meta-analysis of randomized controlled trials and longitudinal studies - Meta-analysis, 2018; 3 studies, 483 people; menopausal women experiencing vasomotor symptoms: no clear difference.
Meta-analysis of the data showed no difference in the frequency and severity of hot flushes, …
Effect of omega-3 supplements on vasomotor symptoms in menopausal women: A systematic review and meta-analysis - Randomised trial, 2025; patients with type 2 diabetes: improves.
fish oil supplementation enhances sleep parameters
Marine n-3 polyunsaturated fatty acids slow sleep impairment progression by regulating central circadian rhythms in type 2 diabetes - Randomised trial, 2022; 66 people; healthy Japanese males and females aged 45 years or older: improves.
factor III (frequent dreaming) scores among the OSA-MA scores were significantly improved
Effect of Docosahexaenoic Acid and Eicosapentaenoic Acid Supplementation on Sleep Quality in Healthy Subjects: A Randomized, Double-Blinded, Placebo-Controlled Trial - Randomised trial, 2021; 84 people; healthy young adults, low oily fish intake: improves.
improvements in actigraphy sleep efficiency (p = 0.030)
Differential Effects of DHA- and EPA-Rich Oils on Sleep in Healthy Young Adults: A Randomized Controlled Trial - Crossover trial, 2020; 52 people; hemodialysis patients with uremic pruritus: improves.
sleep quality scores were different in two groups
The effects of omega-3 on the sleep quality of patients with uremic pruritus undergoing hemodialysis: a randomized crossover study
- Meta-analysis, 2024; 8 studies: improves (the review the verdict rests on).
Panax Ginseng (Korean Ginseng): sleep quality
The studies read are too weak to tell whether Panax Ginseng (Korean Ginseng) changes sleep quality. The evidence is very weak.
3 studies counted of 8 read: 3 trials (103 people in the trials).
- Randomised trial, 2020; 50 people: no clear difference.
no significant differences in the secondary outcome measurements
Efficacy of Korean red ginseng (Panax ginseng) for middle-aged and moderate level of chronic fatigue patients: A randomized, double-blind, placebo-controlled trial - Randomised trial, 2013; 38 people; patients with fibromyalgia: no clear difference.
improvement in sleep (p < .001)
Effects of Panax ginseng extract in patients with fibromyalgia: a 12-week, randomized, double-blind, placebo-controlled trial - Crossover trial, 2013; 15 people; young male healthy volunteers: improves.
Total wake time (TWT) was significantly reduced (P<0.05) and SE was increased (P<0.05), although slow …
Effects of red ginseng extract on sleeping behaviors in human volunteers
- Randomised trial, 2020; 50 people: no clear difference.
Probiotics: sleep quality
The best available review (2025, 6 studies, 424 people) found an improvement in sleep quality. That review studied patients with insomnia. 7 of the 8 studies read agree; 1 found no clear answer. The evidence is moderate.
8 studies counted of 11 read: 7 reviews and 1 trial.
- Systematic review, 2025; 6 studies, 424 people; patients with insomnia: improves (the review the verdict rests on).
significant reduction in Pittsburgh Sleep Quality Index (PSQI)
Impact of probiotics on sleep quality and mood states in patients with insomnia: a systematic review and meta-analysis - Systematic review, 2026; 13 studies, 890 people; adults, healthy and poor sleep quality: improves.
probiotic supplementation significantly reduced PSQI scores
Association between probiotic intervention and sleep quality in the general adult population: a systematic review and meta-analysis - Systematic review, 2026; 19 studies, 762 people: improves.
Overall, probiotic intake appears to modify resting state connectivity and activity, decrease involvement of several …
The effects of oral probiotic intervention on brain structure and function in human adults: a systematic review - Meta-analysis, 2024; 15 studies: improves.
PSQI) scores in the probiotics group was significantly lower
Effects of probiotics on sleep parameters: A systematic review and meta-analysis - Systematic review, 2024; 11 studies; adults with sleep disorders or sub-healthy sleep conditions: improves.
improves sleep states to some extent
Effect of probiotics and paraprobiotics on patients with sleep disorders and sub-healthy sleep conditions: a meta-analysis of randomized controlled trials - Meta-analysis, 2023; 18 studies: unclear: evidence too weak to tell.
not demonstrated to be associated with significant improvement in sleep quality
Effect of gut microbiota modulation on sleep: a systematic review and meta-analysis of clinical trials - Meta-analysis, 2023; people with sleep disturbances: improves.
probiotics supplementation significantly reduced the self-assessed parameter
Microbiota Composition and Probiotics Supplementations on Sleep Quality-A Systematic Review and Meta-Analysis - Randomised trial, 2024; healthy adults under mild stress aged 18-35 years: improves.
exhibited significant improvements in wearable device- measured sleep duration
Lacticaseibacillus paracasei 207-27 alters the microbiota-gut-brain axis to improve wearable device-measured sleep duration in healthy adults: a randomized, double-blind, placebo-controlled trial
- Systematic review, 2025; 6 studies, 424 people; patients with insomnia: improves (the review the verdict rests on).
Rhodiola Rosea: sleep quality
The best available review (2026, 5 studies) found an improvement in sleep quality. That review studied healthy individuals and patients with stress-related or functional disorders. All 2 studies read agree. The evidence is moderate.
2 studies counted of 6 read: 1 review and 1 trial (24 people in the trials).
- Systematic review, 2026; 5 studies; healthy individuals and patients with stress-related or functional disorders: improves (the review the verdict rests on).
improved sleep quality, enhancement of cognitive functions
Clinical evidence for the adaptogenic effects of Withania somnifera and Rhodiola rosea - A systematic review with molecular interpretation of psychometric outcomes - Randomised trial, 2002; 24 people; men living at high altitude: improves.
improving the sleep quality in young men
[The effect of rhodiola and acetazolamide on the sleep architecture and blood oxygen saturation in men living at high altitude]
- Systematic review, 2026; 5 studies; healthy individuals and patients with stress-related or functional disorders: improves (the review the verdict rests on).
Saffron: sleep quality
The studies disagree. The best available review (2022, 8 studies, 431 people) did not settle it for sleep quality, while 10 of the 11 studies read found an improvement. The evidence is very weak.
11 studies counted of 11 read: 5 reviews and 6 trials (534 people in the trials).
- Meta-analysis, 2022; 8 studies, 431 people; people with insomnia: unclear: evidence too weak to tell (the review the verdict rests on).
increased sleep quality (SMD 0.89, 95% CI 0.10 to 1.68
Crocus Sativus for Insomnia: A Systematic Review and Meta-Analysis - Meta-analysis, 2025; 11 studies, 637 people; individuals with obesity: improves.
saffron supplementation (OR = 11.10, P = 0.000)
Nutritional interventions and sleep quality in obese individuals: a systematic review and meta-analysis of randomized control trials - Meta-analysis, 2024; 46 studies: improves.
sleep disorders of -1.91 (95% CI: -2.88, -0.93)
New horizons for the study of saffron (Crocus sativus L.) and its active ingredients in the management of neurological and psychiatric disorders: A systematic review of clinical evidence and mechanisms - Meta-analysis, 2022; healthy adults, insomnia, type 2 diabetes, methadone maintenance: improves.
notable treatment effect on PSQI (MD: -2.14
Effects of saffron supplementation on improving sleep quality: a meta-analysis of randomized controlled trials - Meta-analysis, 2020; 21 studies: improves. The effects of saffron (Crocus sativus L.) on mental health parameters and C-reactive protein: A meta-analysis of randomized clinical trials
- Randomised trial, 2026; 76 people; adults with pulmonary sarcoidosis and sleep disturbances: improves.
Compared with the control group, saffron supplementation significantly improved PSQI (adjusted mean difference [MD], -2.21)
Efficacy of a Saffron-Based (Crocus sativus L.) Herbal Supplement on Sleep Disturbances in Pulmonary Sarcoidosis: A Randomized Single-Blind Controlled Trial - Randomised trial, 2025; 165 people; adults with moderate insomnia: improves.
sleep quality (SQS) improved significantly after 3 weeks
Effect of a saffron extract on sleep quality in adults with moderate insomnia: A decentralized, randomized, double-blind, placebo-controlled trial - Randomised trial, 2025; 52 people; older adults with sleep complaints: improves.
significantly improved subjective sleep quality (p = 0.02)
A standardised saffron extract improves subjective and objective sleep quality in healthy older adults with sleep complaints: results from the gut-sleep-brain axis randomised, double-blind, placebo-controlled pilot study - Randomised trial, 2021; 120 people; adults with unsatisfactory sleep: improves.
greater improvements in sleep quality ratings
An investigation into an evening intake of a saffron extract (affron®) on sleep quality, cortisol, and melatonin concentrations in adults with poor sleep: a randomised, double-blind, placebo-controlled, multi-dose study - Randomised trial, 2021; 66 people: improves.
improved sleep quality, sleep latency, sleep duration, and global scores
Effects of Saffron Extract on Sleep Quality: A Randomized Double-Blind Controlled Clinical Trial - Randomised trial, 2020; 55 people; healthy adults with self-reported sleep problems: improves.
saffron was associated with greater improvements in ISI total score
Effects of saffron on sleep quality in healthy adults with self-reported poor sleep: a randomized, double-blind, placebo-controlled trial
- Meta-analysis, 2022; 8 studies, 431 people; people with insomnia: unclear: evidence too weak to tell (the review the verdict rests on).
Tart Cherry Juice: sleep quality
The studies read are too weak to tell whether Tart Cherry Juice changes sleep quality. The strongest review read studied elderly patients with insomnia. The evidence is very weak.
5 studies counted of 8 read: 1 review and 4 trials (91 people in the trials).
- Systematic review, 2020; 53 studies, 6,832 people; elderly patients with insomnia: unclear: evidence too weak to tell (the review the verdict rests on). Efficacy, acceptability, and tolerability of all available treatments for insomnia in the elderly: a systematic review and network meta-analysis
- Randomised trial, 2026; 44 people; healthy adults: no clear difference.
no significant differences in sleep time or quality
Montmorency tart cherry supplementation does not impact sleep, body composition, cellular health, or blood pressure in healthy adults - Randomised trial, 2022; 19 people; elite female field hockey players: mixed results.
significant interaction effects with regards to the total time in bed
Effects of Short-Term Intake of Montmorency Tart Cherry Juice on Sleep Quality after Intermittent Exercise in Elite Female Field Hockey Players: A Randomized Controlled Trial - Crossover trial, 2018; 8 people; elderly adults with insomnia: improves.
increased sleep time by 84 minutes on polysomnography
Pilot Study of the Tart Cherry Juice for the Treatment of Insomnia and Investigation of Mechanisms - Crossover trial, 2012; 20 people; healthy adults: improves.
significant increases in time in bed, total sleep time and sleep efficiency total
Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality
Theanine: sleep quality
The best available review (2026, 13 studies, 550 people) found an improvement in sleep quality. 4 of the 6 studies read agree; 1 found no clear difference, 1 found a worse result. The evidence is moderate.
Possible harm: 1 study read reported a worse result for sleep quality with Theanine. One abstract says: "all, except atomoxetine, affected sleep quality, such as by reducing total rapid eye movement (REM), non-REM phase, slow-wave sleep time, and longer sleep-onset latency" Check the studies below, and ask a doctor or pharmacist if this applies to you.
6 studies counted of 11 read: 4 reviews and 2 trials (30 people in the trials).
- Systematic review, 2026; 13 studies, 550 people: improves (the review the verdict rests on).
beneficial effects were reported on both objective and participant-reported outcomes
Examining the effect of L-theanine on sleep: a systematic review of dietary supplementation trials - Systematic review, 2026; healthy adults: improves.
can support sleep quality, with little effect
Effects of L-theanine on cognition, mood and sleep: evidence from human trials - Meta-analysis, 2025; 18 studies, 897 people; humans of all ages and health status: improves. The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis
- Systematic review, 2023; children with attention deficit hyperactivity disorder: worsens.
affected sleep quality, such as by reducing total rapid eye movement
Association between sleep pattern and pharmacological treatment in children with attention deficit disorder with hyperactivity: a systematic review - Crossover trial, 2023; healthy young women: no clear difference.
no difference was observed between the theanine
Theanine maintains sleep quality in healthy young women by suppressing the increase in caffeine-induced wakefulness after sleep onset - Crossover trial, 2019; 30 people; healthy adults without major psychiatric illness: improves.
Pittsburgh Sleep Quality Index (PSQI) scores decreased after L-theanine administration
Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial
- Systematic review, 2026; 13 studies, 550 people: improves (the review the verdict rests on).
Valerian: sleep quality
The best available review (2024, 8 studies) found an improvement in sleep quality. That review studied adults with insomnia. 6 of the 9 studies read agree; 3 found no clear difference. The evidence is moderate.
9 studies counted of 11 read: 4 reviews and 5 trials (297 people in the trials).
- Systematic review, 2024; 8 studies; adults with insomnia: improves (the review the verdict rests on).
effective concerning subjective improvement of sleep quality
Does valerian work for insomnia? An umbrella review of the evidence - Meta-analysis, 2020; 10 studies, 1,065 people; people with sleep problems: improves.
effectiveness to improve subjective sleep quality
Valerian Root in Treating Sleep Problems and Associated Disorders-A Systematic Review and Meta-Analysis - Systematic review, 2007; 37 studies; healthy individuals and persons with sleep disturbance or insomnia: no clear difference.
found no significant differences between valerian and placebo
A systematic review of valerian as a sleep aid: safe but not effective - Meta-analysis, 2006; 16 studies, 1,093 people; patients with insomnia: improves.
statistically significant benefit (relative risk of improved sleep = 1.8
Valerian for sleep: a systematic review and meta-analysis - Crossover trial, 2021; 39 people: improves.
reduction was significantly higher in group A compared to group B
The Effects of Valerian on Sleep Quality, Depression, and State Anxiety in Hemodialysis Patients: A Randomized, Double-blind, Crossover Clinical Trial - Randomised trial, 2011; 100 people; postmenopausal women experiencing insomnia: improves.
statistically significant change was reported in the quality of sleep
Effect of valerian on sleep quality in postmenopausal women: a randomized placebo-controlled clinical trial - Crossover trial, 2009; 16 people; older women with insomnia: no clear difference.
no statistically significant differences between valerian and placebo
A randomized clinical trial of valerian fails to improve self-reported, polysomnographic, and actigraphic sleep in older women with insomnia - Randomised trial, 1994; 14 people; elderly poor sleepers: no clear difference. The effect of valerian extract on sleep polygraphy in poor sleepers: a pilot study
- Crossover trial, 1982; 128 people; 128 people tested sleep measures: improves. Aqueous extract of valerian root (Valeriana officinalis L.) improves sleep quality in man
- Systematic review, 2024; 8 studies; adults with insomnia: improves (the review the verdict rests on).
Vitamin D: sleep quality
The best available review (2022, 19 studies) found an improvement in sleep quality. 7 of the 8 studies read agree; 1 found a worse result. The evidence is moderate.
Possible harm: 1 study read reported a worse result for sleep quality with Vitamin D. One abstract says: "overall worse sleep quality (ptrend<0.01). Women who became vitamin D replete (≥32ng/mL) also showed a deterioration in total PSQI sleep quality score" Check the studies below, and ask a doctor or pharmacist if this applies to you.
8 studies counted of 10 read: 5 reviews and 3 trials (301 people in the trials).
- Meta-analysis, 2022; 19 studies: improves (the review the verdict rests on).
statistically significant decrease in the Pittsburgh Sleep Quality Index
Vitamin D Supplementation and Sleep: A Systematic Review and Meta-Analysis of Intervention Studies - Meta-analysis, 2022; 31 studies: improves. Efficacy of dietary supplements on improving sleep quality: a systematic review and meta-analysis
- Meta-analysis, 2022; 5 studies; people with poor sleep quality: improves.
significantly improves sleep quality (MD: -1.32; 95%CI: -2.55 to -0.09; P = 0.04)
The effect of vitamin D on sleep quality: A systematic review and meta-analysis - Meta-analysis, 2020; people with sleep disorders: improves. A meta-analysis: Does vitamin D play a promising role in sleep disorders?
- Meta-analysis, 2019; 2 studies; patients with psychiatric disorders: improves. The effects of vitamin D supplementation on mental health, and biomarkers of inflammation and oxidative stress in patients with psychiatric disorders: A systematic review and meta-analysis of randomized controlled trials
- Randomised trial, 2024; 212 people; chinese individuals with prediabetes: improves.
total PSQI score in vitamin D + calcium group was lower
Effects of vitamin D and/or calcium intervention on sleep quality in individuals with prediabetes: a post hoc analysis of a randomized controlled trial - Randomised trial, 2018; 89 people; 20-50 year-old people with sleep disorders: improves.
sleep score (PSQI) reduced significantly in vitamin recipients
The effect of vitamin D supplement on the score and quality of sleep in 20-50 year-old people with sleep disorders compared with control group - Randomised trial, 2016; overweight postmenopausal women with low vitamin D: worsens.
deterioration in total PSQI sleep quality score
Repletion of vitamin D associated with deterioration of sleep quality among postmenopausal women
- Meta-analysis, 2022; 19 studies: improves (the review the verdict rests on).
Key findings
- Sleep LatencyImproves (the measure goes down)
- Subjective SleepinessImproves (the measure goes up)
- Sleep QualityImproves (the measure goes up)
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Studies cited
100 studies from PubMed
- Analysis of growth hormone releasing hormone and its analogs in urine using nano liquid chromatography coupled with quadrupole/orbitrap mass spectrometry.
- Overview of Epitalon-Highly Bioactive Pineal Tetrapeptide with Promising Properties
- The Antioxidant Tetrapeptide Epitalon Enhances Delayed Wound Healing in an in Vitro Model of Diabetic Retinopathy.
- Neuropharmacological potential of honokiol and its derivatives from Chinese herb Magnolia species: understandings from therapeutic viewpoint
- Honokiol-Rich Magnolia officinalis Bark Extract Attenuates Trauma-Induced Neuropathic Pain
- Early detection of cannabinoids in biological samples based on their affinity interaction with the growth hormone secretagogue receptor.
- An antibody-free, ultrafiltration-based assay for the detection of growth hormone-releasing hormones in urine at low pg/mL concentrations using nanoLC-HRMS/MS.
- Peptides Regulating Proliferative Activity and Inflammatory Pathways in the Monocyte/Macrophage THP-1 Cell Line.
- Epitalon protects against post-ovulatory aging-related damage of mouse oocytes in vitro.
- Dietary gamma-aminobutyric acid (GABA) induces satiation by enhancing the postprandial activation of vagal afferent nerves
- Advances in the detection of growth hormone releasing hormone synthetic analogs.
- A honokiol-enriched Magnolia officinalis Rehder & E.H. Wilson. bark extract possesses anxiolytic-like activity with neuroprotective effect through the modulation of CB1 receptor
- Comparison of magnetic bead surface functionalities for the immunopurification of growth hormone-releasing hormones prior to liquid chromatography-high resolution mass spectrometry.
- Effects of oral gamma-aminobutyric acid (GABA) administration on stress and sleep in humans: a systematic review
- An immuno polymerase chain reaction screen for the detection of CJC-1295 and other growth-hormone-releasing hormone analogs in equine plasma.
- Supplementation of gamma-aminobutyric acid (GABA) affects temporal, but not spatial visual attention
- Netnography of Female Use of the Synthetic Growth Hormone CJC-1295: Pulses and Potions.
- Qualitative identification of growth hormone-releasing hormones in human plasma by means of immunoaffinity purification and LC-HRMS/MS.
- Expanded test method for peptides >2 kDa employing immunoaffinity purification and LC-HRMS/MS.
- Neurotransmitters as food supplements: the effects of GABA on brain and behavior
- Effect of delta sleep-inducing peptide on the expression of antioxidant enzyme genes in the brain and blood of rats during physiological aging.
- [Main mechanisms of rhabdomyolysis-caused kidney injury and their correction by organospecific peptides].
- [Peptides and CCL11 and HMGB1 as molecular markers of aging: literature review and own data].
- Effect of Magnolia officinalis and Phellodendron amurense (Relora®) on cortisol and psychological mood state in moderately stressed subjects
- Neuro-modulating effects of honokiol: a review
- Immunoaffinity purification of peptide hormones prior to liquid chromatography-mass spectrometry in doping controls.
- Effect of delta sleep-inducing peptide on oxidative modification of proteins in rat tissues and blood during physiological aging.
- Effects of melatonin and epithalamin on the content of protein and lipid peroxidation products in rat cortex and hippocampus under conditions of acute hypoxia.
- [Peptide Ala-Glu-Asp-Gly and interferon gamma: their role in immune response during aging].
- Melatonin and pineal gland peptides are able to correct the impairment of reproductive cycles in rats.
- The natural products magnolol and honokiol are positive allosteric modulators of both synaptic and extra-synaptic GABA(A) receptors
- Honokiol promotes non-rapid eye movement sleep via the benzodiazepine site of the GABA(A) receptor in mice
- Safety and tolerability of subcutaneous CJC-1295 in healthy adults: Phase I clinical trial
- Activation of the GH/IGF-1 axis by CJC-1295, a long-acting GHRH analog, results in serum protein profile changes in normal adult subjects
- Pulsatile vs continuous growth hormone secretion: clinical implications
- [Endogenous anticonvulsants: neuropeptide Y and delta sleep inducing peptide].
- Effect of a proprietary Magnolia and Phellodendron extract on stress levels in healthy women: a pilot, double-blind, placebo-controlled clinical trial
- Interaction of Delta sleep-inducing peptide and valproate on metaphit audiogenic seizure model in rats.
- Normalizing effect of the pineal gland peptides on the daily melatonin rhythm in old monkeys and elderly people
- [Age-related changes of exercise capacity and some biochemical indices of rat muscles under influence of different light conditions and pineal preparations].
- Antioxidant properties of geroprotective peptides of the pineal gland.
- Effect of epithalamin on the rhythm of immune and endocrine systems functioning in patients with chronic coronary disease.
- Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults
- Once-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, normalizes growth in the GHRH knockout mouse
- Growth hormone-releasing hormone and growth hormone secretagogues: clinical applications
- Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog.
- Delta sleep-inducing peptide (DSIP): a still unresolved riddle
- Delta-sleep-inducing peptide potentiates anticonvulsive activity of valproate against metaphit-provoked audiogenic seizure in rats.
- Anti-aging peptide bioregulators induce reactivation of chromatin.
- [Comparative study of the effects of melatonin and epitalon on the protracted memory under the shuttle labyrinth test conditions in rats in the course of aging].
- [Influence of light regimens, melatonin, and epitalon on amylase activity in the pancreas and small intestine in rats of different age].
- [Effect of age, different light conditions, melatonin, and epitalon on lysosomal proteinase activity in the liver and kidneys of rats].
- Effect of a proprietary Magnolia and Phellodendron extract on weight management: a pilot, double-blind, placebo-controlled clinical trial
- Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats: identification of CJC-1295 as a long-lasting GRF analog
- Antiepileptic activity of delta sleep-inducing peptide and its analogue in metaphit-provoked seizures in rats.
- Pineal peptides restore the age-related disturbances in hormonal functions of the pineal gland and the pancreas
- [Effect of epitalon and melatonin on life span and spontaneous carcinogenesis in senescence accelerated mice (SAM)].
- Antigen-induced changes in the endocrine function of the thymus in CBA mice during aging: role of peptide factors released by the pineal gland.
- Delta sleep-inducing peptide and its tetrapeptide analogue alleviate severity of metaphit seizures.
- [Behavioral and electroencephalographic effects of delta sleep inducing peptide and its analogue on metaphit-induced audiogenic seizures in rats].
- Effect of peptide preparation epithalamin on circadian rhythm of epiphyseal melatonin-producing function in elderly people
- Effects of pineal peptides on circadian dynamics of spermatogonia proliferation in albino rats.
- Effect of epithalamin on circadian relationship between the endocrine function of the thymus and melatonin-producing function of the pineal gland in elderly people.
- [The pineal gland's peptides factors and the rhythms of functions of the thymus and bone marrow in animals during aging].
- [Effect of epitalon on the immunity and hemostasis in hypophysectomized chicken and old hens].
- Pharmacokinetics, safety, and tolerability of increasing repeat doses of CJC-1295 in healthy volunteers
- Delta sleep inducing peptide (DSIP): effect on respiration activity in rat brain mitochondria and stress protective potency under experimental hypoxia
- Epithalon peptide induces telomerase activity and telomere elongation in human somatic cells
- The role of pineal gland in breast cancer development.
- [Effect of epithalamin on free-radical reactions in the formed elements of blood from breast cancer patients].
- Effect of Epitalon on biomarkers of aging, life span and spontaneous tumor incidence in female Swiss-derived SHR mice.
- [Regulating effect of pineal gland peptides on development of T-lymphocytes in CBA aging mice: role of microenvironment of immune system organs and neuroendocrine factors].
- Epitalon and colon carcinogenesis in rats: proliferative activity and apoptosis in colon tumors and mucosa.
- Peptides and Ageing
- Aging of the pineal gland
- Inhibitory effect of the peptide epitalon on the development of spontaneous mammary tumors in HER-2/neu transgenic mice.
- Epithalon decelerates aging and suppresses development of breast adenocarcinomas in transgenic her-2/neu mice.
- Effects of epithalon on activities gastrointestinal enzymes in young and old rats.
- Growth hormone-releasing peptides, ghrelin, and growth hormone secretagogues
- Synthetic tetrapeptide epitalon restores disturbed neuroendocrine regulation in senescent monkeys.
- Effect of pineal tetrapeptide on antioxidant defense in Drosophila melanogaster.
- Studies of cytokines in nerve tissue cultures.
- Peptide bioregulators inhibit apoptosis.
- Effects of intranasal growth hormone-releasing hormone on sleep and sleep-related growth hormone release in aged men
- [Long-term results of comprehensive treatment for cervical cancer with poor prognosis].
- Honokiol, a putative anxiolytic agent extracted from magnolia bark, has no diazepam-like side-effects in mice
- Opioid detoxification with delta sleep-inducing peptide: results of an open clinical trial
- [Effect of melatonin and epithalamin on the antioxidant defense system activity in rats].
- Effect of melatonin and pineal peptide preparation epithalamin on life span and free radical oxidation in Drosophila melanogaster.
- [Comparison of the antioxidant properties of melatonin, epithalamin, and glutathione by the method of luminol-dependent chemiluminescence in vitro].
- [Effect of melatonin and epithalamin on life span and lipid peroxidation in Drosophila melanogaster].
- GHRH increases slow-wave sleep and REM sleep in humans
- [Melatonin and epithalamin extinguishes the lipid peroxidation process in rats].
- Delta-sleep-inducing peptide sequels in the mechanisms of resistance to emotional stress
- [Melatonin and epithalamin inhibit the process of free radical oxidation in rats].
- Twenty years of study on effects of pineal peptide preparation: epithalamin in experimental gerontology and oncology.
- Induction of a prolonged increase in growth hormone (GH) levels by GH-releasing hormone
- Delta sleep-inducing peptide administration does not influence growth hormone and prolactin secretion in normal women.
- [The delta sleep-inducing peptide and its role in modulating epileptic activity].
- [The use of peptide preparations of the epiphysis (pineal gland) in oncology: 20 years' experience of research on epithalamin].