Condition

Chemotherapy Side Effects

Chemotherapy side effects arise because drugs aimed at fast-dividing cancer cells also hit healthy fast-dividing cells in the gut, bone marrow, hair follicles and nerves. Probiotics have the strongest evidence, and trials found appetite went up, while ginger added to usual anti-nausea medicines eased nausea and vomiting, with moderate evidence. One small lemon balm trial found no clear difference in nerve pain, and most other options have limited evidence.

Sources: PMID 38868804

Supplements studied: 9
Graded outcomes: 5
Trials: 10
People studied: 2,802

Evidence by supplement

Strong
Moderate
Limited
Very limited

9 supplements

Probiotics

Probiotics: outcomes studied for Chemotherapy Side Effects
Grade	Outcome	Effect	Size	Studies	People
	Appetite Moderate Increase	Worsens (the measure goes up)	Moderate effect		227 people
	Diarrhea Symptoms	Improves (the measure goes down)		4 studies	327 people
Studies that measured diarrhea symptoms Oral probiotic supplementation to alleviate diarrhea induced by fluoropyrimidines or irinotecan-based chemotherapy: A systematic review and meta-analysis.Complement Ther Med · PMID 39993479 Evaluation of the efficacy of probiotics in the chemoradiotherapy of colorectal cancer: a meta-analysis of Randomized Controlled Trials.BMC Gastroenterol · PMID 40301781 Efficacy and safety of Saccharomyces boulardii CNCM I-745 for the treatment of pediatric acute diarrhea in China: a systematic review and meta-analysis.Front Cell Infect Microbiol · PMID 40535538 and 1 more on the Probiotics page
	Mucositis Symptoms	Improves (the measure goes down)		2 studies	1,055 people
Studies that measured mucositis symptoms Efficacy of probiotics in the treatment of oral mucositis in head and neck cancer patients: A systematic review and meta-analysis.Microb Pathog · PMID 38971507 The effect of probiotics on severe oral mucositis in cancer patients undergoing chemotherapy and/or radiotherapy: A meta-analysis.J Stomatol Oral Maxillofac Surg · PMID 39187039
	Weight	Improves (the measure goes down)		1 study	1,089 people
Studies that measured weight Effects of oral supplementation of probiotics on body weight and visceral fat in obese patients: a meta-analysis and systematic review.Sci Rep · PMID 39984625
	Bloating	Improves (the measure goes down)			125 people
	Constipation Signs and Symptoms	Improves (the measure goes down)			142 people
	Quality of Life	Improves (the measure goes up)			1,089 people

Cannabis

Cannabis: outcomes studied for Chemotherapy Side Effects
Grade	Outcome	Effect	Size	Studies	People
	Nausea Symptoms Moderate Improvement	Improves (the measure goes down)	Moderate effect		81 people
	Vomiting	Improves (the measure goes down)		1 study	81 people
Studies that measured vomiting Oral THC:CBD cannabis extract for refractory chemotherapy-induced nausea and vomiting: a randomised, placebo-controlled, phase II crossover trialAnn Oncol · PMID 32801017

Ashwagandha

Fatigue Symptoms: improves
Condition-Related Fatigue
Insomnia Signs and Symptoms: improves

Ashwagandha: outcomes studied for Chemotherapy Side Effects
Grade	Outcome	Effect	Size	Studies	People
	Fatigue Symptoms Small Improvement	Improves (the measure goes down)	Small effect		100 people
	Condition-Related Fatigue No effect		NoneNo effect	1 study	100 people
Studies that measured condition-related fatigue A Randomized, Double-Blind, Placebo-Controlled, Crossover Study Examining the Hormonal and Vitality Effects of Ashwagandha ( Withania somnifera) in Aging, Overweight MalesAm J Mens Health · PMID 30854916
	Insomnia Signs and Symptoms	Improves (the measure goes down)		1 study	100 people
Studies that measured insomnia signs and symptoms Effect of Withania somnifera (Ashwagandha) on the development of chemotherapy-induced fatigue and quality of life in breast cancer patientsIntegr Cancer Ther · PMID 23142798
	Pain	Improves (the measure goes down)		1 study	100 people
Studies that measured pain A randomized, double blind placebo controlled study of efficacy and tolerability of Withaina somnifera extracts in knee joint painJ Ayurveda Integr Med · PMID 27647541
	Social Functioning	Improves (the measure goes up)			100 people
	Subjective Well-Being	Improves (the measure goes up)			100 people

Lemon Balm

Pain
Quality of Life: improves

Lemon Balm: outcomes studied for Chemotherapy Side Effects
Grade	Outcome	Effect	Size	Studies	People
	Pain No effect		NoneNo effect	1 study	72 people
Studies that measured pain Effect of Melissa officinalis on Chemotherapy-Induced Peripheral Neuropathy in Cancer Patients: A Randomized Trial.Int J Hematol Oncol Stem Cell Res · PMID 38868804
	Quality of Life	Improves (the measure goes up)			72 people

Ginger (Zingiber officinale)

Nausea Symptoms: changes; see studies

Ginger (Zingiber officinale): outcomes studied for Chemotherapy Side Effects
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Nausea Symptoms	Changes; see studies		9 studies	60 people
Studies that measured nausea symptoms Ginger syrup as an antiemetic in early pregnancyAltern Ther Health Med · PMID 12233808 Ginger for nausea and vomiting in pregnancy: randomized, double-masked, placebo-controlled trialObstet Gynecol · PMID 11275030 Effect of a ginger extract on pregnancy-induced nausea: a randomised controlled trialAust N Z J Obstet Gynaecol · PMID 14712970 and 6 more on the Ginger (Zingiber officinale) page

Zinc

Mucositis Symptoms: improves

Zinc: outcomes studied for Chemotherapy Side Effects
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Mucositis Symptoms	Improves (the measure goes down)		4 studies	194 people
Studies that measured mucositis symptoms Zinc sulfate in the prevention of radiation-induced oropharyngeal mucositis: a prospective, placebo-controlled, randomized studyInt J Radiat Oncol Biol Phys · PMID 14697435 The effect of zinc sulfate in the prevention of high-dose chemotherapy-induced mucositis: a double-blind, randomized, placebo-controlled studyHematol Oncol · PMID 21692101 A randomized double-blind, placebo-controlled trial of zinc sulfate supplementation for alleviation of radiation-induced oral mucositis and pharyngitis in head and neck cancer patientsJ Med Assoc Thai · PMID 23720981 and 1 more on the Zinc page

Vitamin B6

Hand-Foot Syndrome Symptoms: improves

Vitamin B6: outcomes studied for Chemotherapy Side Effects
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Hand-Foot Syndrome Symptoms	Improves (the measure goes down)		2 studies	5 people
Studies that measured hand-foot syndrome symptoms A randomised study evaluating the use of pyridoxine to avoid capecitabine dose modificationsBr J Cancer · PMID 22814578 Pyridoxine therapy for palmar-plantar erythrodysesthesia associated with continuous 5-fluorouracil infusionInvest New Drugs · PMID 2345070

S-adenosylmethionine

Liver Enzymes: changes; see studies

S-adenosylmethionine: outcomes studied for Chemotherapy Side Effects
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Liver Enzymes	Changes; see studies		1 study	50 people
Studies that measured liver enzymes S-adenosylmethionine (AdoMet) supplementation for treatment of chemotherapy-induced liver injuryAnticancer Res · PMID 14981985

Yarrow

Mucositis Symptoms: improves

Yarrow: outcomes studied for Chemotherapy Side Effects
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Mucositis Symptoms	Improves (the measure goes down)		1 study	56 people
Studies that measured mucositis symptoms Effect of adding the herb Achillea millefolium on mouthwash on chemotherapy induced oral mucositis in cancer patients: A double-blind randomized controlled trial.Eur J Oncol Nurs · PMID 25667123

Key findings

AppetiteProbioticsWorsens (the measure goes up)
Nausea SymptomsCannabisImproves (the measure goes down)
Fatigue SymptomsAshwagandhaImproves (the measure goes down)

The Chemotherapy Side Effects Support protocol

2 primary supplements · 8 supporting supplements

Probiotics10–50 billion CFU daily; Lactobacillus rhamnosus GG or multi-strain formulas
Ginger1–2 g daily in divided doses starting 3 days before chemotherapy

See the full protocol

Studies cited

1 study from PubMed

Effect of oral administration of kefir on serum proinflammatory cytokines on 5-FU induced oral mucositis in patients with colorectal cancerInvest New Drugs · PMID 18762864

Evidence by supplement

Key findings

The Chemotherapy Side Effects Support protocol

Studies cited

Related conditions

Supplement stack for Chemotherapy Side Effects