Alzheimer’s Disease
Alzheimer’s disease is a neurodegenerative disorder that impairs cognitive function, especially memory formation. It is the most common type of dementia.
Quick Answer
What it is
Alzheimer’s disease is a neurodegenerative disorder that impairs cognitive function, especially memory formation. It is the most common type of dementia.
Key findings
- Grade B: Cognitive Function (MMSE) (Huperzine A)
- Grade B: Memory (WMS) (Huperzine A)
- Grade B: Cognitive Function (ADAS-Cog) (Huperzine A)
Safety
- Preclinical studies demonstrated idebenone protects against amyloid beta toxicity in cortical neurons (PMID:32925607).
- A community-based epidemiological study of 575 deceased participants (Rush Memory and Aging Project) found that higher pelargonidin intake was associated with reduced amyloid-beta accumulation and fewer phosphorylated tau tangles in brain tissue, particularly among those without APOE e4 risk factor.
- lowest quintile of dietary flavonol intake was associated with reduced Alzheimer's dementia risk (HR 0.52, 95% CI 0.33-0.84).
ℹ️ Quick Facts
Quick Facts: Alzheimer’s Disease
- Supplements Studied:19
- Research Trials:32
- Total Participants:29,810
- Top Supplement:Saffron (B)
32 trials
29,810 participantsppts
19 supps · 45 outcomes
Evidence-Based Protocol
Supplement stack ranked by research quality
Primary Stack (Tier 1)
1-2g DHA daily
DHA is a major structural component of brain cell membranes; supports neuronal function and may reduce amyloid pathology
25 studies | 3,000 participants
100-300mg daily
Essential phospholipid for neuronal membrane function; supports neurotransmitter release and cognitive function
15 studies | 800 participants
Supporting Stack (Tier 2)
500-3000mg daily
Stimulates nerve growth factor (NGF) synthesis, promoting neurogenesis and potentially slowing cognitive decline
8 studies | 300 participants
500-1000mg daily (enhanced absorption formula)
Crosses blood-brain barrier; anti-inflammatory and may inhibit amyloid plaque formation
10 studies | 500 participants
300-600mg 2-3x daily
Choline source that crosses BBB; supports acetylcholine synthesis, critical for memory and learning
12 studies | 600 participants
120-240mg standardized extract daily
Improves cerebral blood flow, has antioxidant effects, and may modestly benefit cognitive function
30 studies | 3,000 participants
B6 50mg, B12 500-1000mcg, Folate 400-800mcg daily
Reduce homocysteine (neurotoxic); deficiency accelerates brain atrophy and cognitive decline
20 studies | 2,000 participants
How It Works
Alzheimer's disease is a progressive brain disorder characterized by memory loss, confusion, and eventually loss of ability to perform daily tasks. It involves the accumulation of amyloid plaques and tau tangles, chronic brain inflammation, and loss of neurons—particularly those using acetylcholine. While no supplement can cure Alzheimer's, some may support brain health and potentially slow decline.
IMPORTANT: These supplements are meant to complement, not replace, medical treatment. Work closely with a neurologist for Alzheimer's care.
•Omega-3 Fatty Acids (DHA) are critical for brain structure and function—DHA makes up about 40% of the fatty acids in neuronal membranes. People with higher DHA levels have lower rates of Alzheimer's. While studies in established Alzheimer's show mixed results, DHA may be more beneficial earlier in the disease process or for prevention. It has anti-inflammatory effects and may reduce amyloid accumulation.
•Phosphatidylserine is a phospholipid essential for neuronal membrane function. It supports neurotransmitter release and receptor activity. Studies show it can improve memory and cognitive function in age-related decline, with FDA-qualified health claims for cognitive function.
•Lion's Mane Mushroom is unique in that it stimulates nerve growth factor (NGF) production—a protein essential for neuron survival and function. This could theoretically support neuroplasticity and help maintain brain function. Studies in mild cognitive impairment show improved cognitive scores.
•Curcumin has potent anti-inflammatory and antioxidant properties and can cross the blood-brain barrier. Laboratory studies show it can inhibit amyloid plaque formation and reduce tau tangles. Population studies in India (where turmeric consumption is high) show lower Alzheimer's rates. Use enhanced-absorption formulas.
•Alpha-GPC is the most effective choline supplement for the brain. It crosses the blood-brain barrier and increases acetylcholine synthesis—the neurotransmitter most affected in Alzheimer's. Studies show it improves cognitive function in dementia patients.
•Ginkgo Biloba improves blood flow to the brain and has antioxidant effects. Large studies show modest benefits for cognitive function in dementia, comparable to cholinesterase inhibitors in some trials. EGb 761 is the most studied standardized extract.
•B Vitamins are essential because high homocysteine levels (common with B vitamin deficiency) are associated with faster brain atrophy and cognitive decline. Supplementation with B6, B12, and folate reduces homocysteine and significantly slows brain atrophy in people with mild cognitive impairment.
Expected timeline: Effects are gradual and aimed at slowing decline rather than reversing it. Lion's mane: 4-16 weeks. B vitamins: 8-12 weeks for homocysteine reduction. Other supplements: ongoing support over months to years.
Generated from peer-reviewed researchSchema v2.0
Supplements for Alzheimer’s Disease
Sorted by strength of evidence
Detailed Outcomes
Grade:
Effect:
Size:
Sort:
|
B
Cognitive Function (MMSE)
Significant improvement in MMSE scores at 8, 12, and 16 weeks (meta-analysis)
20 studies1823 participants
moderate↑Improves
B
Memory (WMS)
Significant improvement in Wechsler Memory Scale at 8 and 12 weeks
8 studies600 participants
moderate↑Improves
B
Cognitive Function (ADAS-Cog)
2.27-point improvement at 400 mcg BID (Phase II trial)
3 studies210 participants
moderate↑Improves
C
Activities of Daily Living
Improved ADL scores at 6, 12, and 16 weeks
6 studies400 participants
moderate↑Improves
D
Cognitive Function (200 mcg BID)
Lower dose (200 mcg BID) showed no demonstrable effect in Phase II trial
1 study210 participants
small↑Improves
B
Alzheimer's Disease Symptoms
Small Improvement
3 studies157 participants
small↓Improves
?
Cognitive Decline
1 study68 participants
↑Worsens
C
Cognitive Function in Alzheimer's Disease
Huperzine-A, the primary active alkaloid from Huperzia serrata, has multiple RCTs and a Cochrane review showing cognitive benefits in Alzheimer's patients via acetylcholinesterase inhibition. However, these trials used isolated Huperzine-A rather than whole clubmoss extract, warranting a lower grade for the whole herb. One animal study using Japanese H. serrata extract demonstrated amelioration of scopolamine-induced cognitive impairment in mice.
8 studies
moderate↑Improves
C
Neuroprotection
Multiple animal and in vitro studies demonstrate neuroprotective effects against ischemia and glutamate excitotoxicity. Key alkaloids (GME, rhynchophylline, isorhynchophylline) protect neurons via 5-HT1A partial agonism, NMDA receptor modulation, calcium channel effects, and anti-inflammatory activity in microglia. No isolated Gou-teng human neuroprotection trials exist.
8 studies
moderate↑Improves
D
Agitation (Dementia-Related)
Human studies of the Yokukansan formula (containing Gou-teng as a key ingredient) show benefit for dementia-related behavioral symptoms and agitation. However, effects cannot be attributed specifically to isolated Gou-teng as Yokukansan is a multi-herb formula. GME's aripiprazole-like partial D2 agonist mechanism provides a plausible pharmacological basis for antipsychotic-like effects observed in animal models.
5 studies
small↓Worsens
C
Neuroprotection
In rodent models, Convolvulus pluricaulis extracts protect against cerebral ischemia-reperfusion injury (reducing lipid peroxidation and increasing SOD, catalase, glutathione), attenuate 3-nitropropionic acid-induced neurotoxicity relevant to Huntington's disease, and reduce tau and amyloid precursor protein expression in a scopolamine-induced Alzheimer's model. A Drosophila study confirmed rescue of tau-induced neurotoxicity and lifespan extension in a transgenic Alzheimer's fly model.
5 studies
moderate↑Improves
C
Alzheimer's Disease Pathology
In AD mouse models, 7,8-DHF reversed memory deficits, reduced BACE1 and beta-amyloid levels, increased dendritic spine density, and reversed oxidative stress and mitochondrial dysfunction. Consistent neuroprotective effects observed across multiple AD rodent models including scopolamine-induced and ICV-STZ sporadic AD models.
4 studies
moderate↓Improves
C
Alzheimer's Disease Biomarkers
In APP/PS1 transgenic Alzheimer's mice, hederagenin (25–50 mg/kg/day for 2 months) improved cognitive performance in Morris water maze, object recognition, and Y-maze tests while promoting amyloid-beta degradation via PPARα/TFEB-mediated autophagy. Additional studies in SH-SY5Y cells and C. elegans models confirmed reduced Aβ deposition, decreased oxidative damage via PI3K/Akt and PTPN1 signaling.
4 studies
moderate↓Improves
C
Cognitive Function in Dementia
Limited human studies in dementia patients showed modest cognitive benefits. Preclinical studies demonstrated idebenone protects against amyloid beta toxicity in cortical neurons (PMID:32925607). Nootropic use in cognitively healthy individuals is not supported by human evidence.
4 studies100 participants
small↑Improves
C
Neuroprotection
In rodent models of Parkinson's and Alzheimer's disease, longan flower, aril, and polysaccharide extracts consistently attenuated neurotoxicity, improved learning and memory, increased BDNF expression, reduced amyloid-beta and phosphorylated-tau, and enhanced microglial phagocytosis via RAS/MEK/ERK and PI3K/Akt/mTOR pathways. No human studies on cognition exist.
4 studies
moderate↑Improves
C
Cognitive Function in Alzheimer's Disease
A Chinese Phase 3 RCT (n=818, 36 weeks) found a statistically significant improvement in ADAS-Cog12 scores (-2.15 points vs placebo, p<0.0001), but secondary endpoints (CIBIC+, ADCS-ADL) were not significant. A Phase 2 RCT (n=242, 24 weeks) did not reach significance on the primary ADAS-Cog12 endpoint (p=0.30 for 900mg). A small RCT (n=72, 48 weeks) reported improvements comparable to donepezil. A meta-analysis of 3 RCTs (n=1,108) favored GV-971 on ADAS-Cog12 but not other scales. Graded C rather than B due to inconsistent primary endpoint results across trials, failure to meet secondary endpoints, early termination of the global Phase 3 replication trial, and non-renewal of China's conditional approval in 2024.
4 studies1132 participants
small↑Improves
C
Alzheimer's Disease Neuropathology
A community-based epidemiological study of 575 deceased participants (Rush Memory and Aging Project) found that higher pelargonidin intake was associated with reduced amyloid-beta accumulation and fewer phosphorylated tau tangles in brain tissue, particularly among those without APOE e4 risk factor. Preclinical studies also show pelargonidin restores amyloid-beta-induced deficits in animal models.
2 studies575 participants
moderate↓Improves
C
Cerebral Glucose Utilization
Small Increase
1 study8 participants
small↑Worsens
?
Cognitive Decline
3 studies92 participants
↑Worsens
C
Alzheimer's Disease Symptoms
Moderate Improvement
1 study261 participants
moderate↓Improves
?
Cognitive Decline
1 study261 participants
↑Worsens
C
Cognitive Decline
Small Improvement
1 study27 participants
small↓Improves
?
Oxidative Stress Biomarkers
1 study27 participants
↑Worsens
C
Cognition
Small Improvement
1 study16 participants
small↑Improves
?
Executive Function
1 study16 participants
↑Improves
?
Memory
1 study16 participants
↑Improves
?
Reaction Time
1 study16 participants
↑Improves
?
Sleep Quality
1 study16 participants
↑Improves
?
Subjective Well-Being
1 study16 participants
↑Improves
C
Alzheimer's Disease Risk
A large prospective cohort study (Rush Memory and Aging Project, n=921, mean age 81) found that highest vs. lowest quintile of dietary flavonol intake was associated with reduced Alzheimer's dementia risk (HR 0.52, 95% CI 0.33-0.84). Kaempferol showed the strongest association (HR 0.49), followed by myricetin and isorhamnetin (both HR 0.62). Interestingly, quercetin alone did not reach significance.
1 study921 participants
moderate↓Improves
D
Body Fat
No effect
8 studies516 participants
none
?
Body Mass Index (BMI)
25 studies1418 participants
↑Worsens
?
Weight
23 studies1265 participants
↑Worsens
?
Waist circumference
11 studies753 participants
↑Worsens
D
Neuroprotection
Multiple preclinical studies demonstrate salidroside protects neurons against ischemia, polyglutamine toxicity, and oxidative damage in cell and animal models. Mechanisms include HSC70/BDNF signaling activation, antioxidant activity, and reduced neuroinflammation via MAPK/NF-kB pathways.
7 studies
moderate↑Improves
D
Alzheimer's Disease Risk
No effect
5 studies14262 participants
none
?
Alzheimer's Disease Symptoms
2 studies774 participants
↑Worsens
?
Cognition
1 study820 participants
↑Improves
D
Attention
No effect
5 studies402 participants
none
?
Cognition
6 studies419 participants
↑Improves
?
Memory
6 studies517 participants
↑Improves
D
Neuroprotection
Polymethoxyflavones (nobiletin, tangeretin) found in orange peel show neuroprotective effects in rodent models of Alzheimer's and Parkinson's disease and are able to cross the blood-brain barrier. No controlled human trials have been conducted to date.
5 studies
small↑Improves
D
Neuroprotection
In Drosophila Alzheimer's disease models, jatamansinol extended lifespan, improved locomotor activity, enhanced learning and memory, and reduced both tau and amyloid-beta protein levels. In rat models, N. jatamansi extract reversed reserpine-induced orofacial dyskinesia and catalepsy, suggesting anti-parkinsonian potential. All evidence is preclinical.
4 studies
moderate↑Improves
D
Neuroprotection
In preclinical models, P. olacoides extract protected rat hippocampal slices from oxygen-glucose deprivation, reduced brain lipid peroxidation and free radical production in aged mice, and prevented amyloid-beta(1-42)-induced cognitive impairment and amyloid deposits in a mouse Alzheimer's model. All studies from a single research group.
3 studies
moderate↑Improves
D
Cognitive Function
In rodent models, mulberry fruit extract enhanced memory via induction of nerve growth factor (PMID:23182412). Two studies in Alzheimer's disease mouse models showed the extract alleviated cognitive impairment by promoting amyloid-β clearance and inhibiting neuroinflammation (PMID:32488469), and reduced amyloid-β oligomer-induced cognitive disturbance and oxidative stress (PMID:34387016).
3 studies
moderate↑Improves
D
Neuroprotection
In vitro and animal studies suggest myricetin may protect against neurodegeneration by modifying amyloid-beta conformation, interfering with secretase activity, and reducing post-ischemic brain damage. Identified as a candidate molecule for Alzheimer's disease research, but no human data exist.
3 studies
small↑Improves
D
Neuroinflammation in Alzheimer's Disease Models
In transgenic Alzheimer's mouse models, 5-month NR supplementation reduced microglial activation, suppressed NLRP3 inflammasome, decreased DNA damage and cellular senescence, and improved cognitive function and synaptic plasticity via the cGAS-STING pathway (Hou et al., 2021). Additional preclinical and review evidence supports NAD+ precursors for neurodegeneration, but no human trials have tested cognitive endpoints in Alzheimer's patients.
3 studies
moderate↓Improves
D
Cholinesterase Inhibition
In vitro enzyme assays demonstrate palmatine inhibits acetylcholinesterase with IC50 of 0.62 μM (second only to berberine at 0.47 μM among protoberberine alkaloids) and butyrylcholinesterase at IC50 3.32-6.84 μM. Two independent studies confirm sub-micromolar AChE inhibitory potency, a mechanism relevant to Alzheimer's disease therapeutics, though no in vivo or human data exist.
3 studies
moderate↑Improves
D
Neuroprotection
In rodent models, Anacyclus pyrethrum reduced oxidative stress markers, restored antioxidant enzyme activity, and may reduce amyloid-beta accumulation via Bcl-2/Bax modulation (PMID:31710948). A 2023 in vitro study confirmed anti-Alzheimer enzyme inhibitory activity of akarkara root-derived metabolites through bioassay-guided fractionation (PMID:37978514).
2 studies
small↑Improves
D
Neuroinflammation
In 5xFAD transgenic Alzheimer's mice, A. iwayomogi extract improved cognitive function in Morris Water Maze tests, reduced amyloid-beta burden, and suppressed glial overactivation via AKT/autophagy-lysosomal pathways (n=12-18/group). Separately, the isolated compound yomogin (5 mg/kg) suppressed LPS-induced neuroinflammation in mice by inhibiting JNK/ERK/p38 MAPK phosphorylation (n=5/group). All preclinical.
2 studies
small↓Improves
D
Alzheimer's Disease Biomarker Engagement
A small open-label human trial evaluated safety and target engagement of two OAA doses in Alzheimer's patients (Vidoni et al. 2021). The study demonstrated safety and some evidence of target engagement but was designed as a safety/biomarker study, not an efficacy trial. Supported by preclinical evidence of OAA-mediated neuroprotection and mitochondrial biogenesis in brain tissue.
2 studies30 participants
small↑Improves
D
Alzheimer's Disease Risk
No effect
1 study2487 participants
none
?
Cognitive Decline
4 studies3358 participants
↑Worsens
?
Alzheimer's Disease Symptoms
2 studies775 participants
↑Worsens
?
Cognition
1 study96 participants
↑Improves
?
Subjective Well-Being
1 study371 participants
↑Improves
?
Tinnitus Symptoms
1 study371 participants
↑Worsens
?
Verbal Fluency
1 study96 participants
↑Improves
D
Alzheimer's Disease Symptoms
Mitsubishi Tanabe Pharma conducted a Phase 2a clinical trial for Alzheimer's disease. The trial failed to meet efficacy endpoints and development was discontinued for this indication. Despite a plausible HACU-based mechanism, human evidence does not support benefit in Alzheimer's disease.
1 study
small↓Improves
?
Alzheimer's Disease Symptoms
2 studies177 participants
↑Worsens
?
Dementia Symptoms
1 study53 participants
↑Worsens
?
Alzheimer's Disease Symptoms
1 study34 participants
↑Worsens
?
Cognitive Decline
1 study241 participants
↑Worsens
?
Alzheimer's Disease Symptoms
1 study295 participants
↑Worsens
?
Cognition
1 study702 participants
↑Improves
?
Alzheimer's Disease Symptoms
1 study24 participants
↑Worsens
?
Cognitive Decline
1 study30 participants
↑Worsens
?
Alzheimer's Disease Symptoms
1 study210 participants
↑Worsens
Research Citations (2)
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