{"entity":{"id":"garlic-supplements","kind":"technology","name":"Garlic supplements","aka":["Allium sativum","Aged garlic extract","Kyolic"],"tldr":"Garlic in food is harmless, and some studies link eating more of it with fewer stomach and bowel cancers, but the evidence is mixed. Concentrated garlic supplements thin the blood, so they should be stopped a week before surgery and avoided with blood thinners or low platelets.","summary":"Garlic is used as a food and as a supplement for cholesterol, blood pressure, infections and cancer. Memorial Sloan Kettering's About Herbs summary describes the cancer evidence as mixed: in a large trial, long-term garlic supplementation was associated with lower gastric cancer mortality but not incidence, while other data found neither; meta-analyses disagree on colorectal cancer; and inverse associations with endometrial, prostate and other cancers come from observational studies. There is no evidence that garlic treats an established cancer. Because garlic reduces platelet aggregation and can raise the INR, MSK advises against using supplements with anticoagulants or with platelet problems, and stopping at least seven days before surgery; it lists perioperative bleeding and a spinal epidural haematoma after heavy use. Garlic extract induced the drug transporter P-glycoprotein in healthy volunteers, and in another study in healthy volunteers garlic supplements lowered levels of an HIV protease inhibitor (peak levels by 54 per cent and trough levels by 49 per cent), showing that a supplement can lower drug exposure enough to matter. Raw garlic applied to the skin causes chemical burns.","status":"phase-2","asOf":"2026-11-04","links":[{"label":"MSK About Herbs: Garlic (page last updated 18 November 2022)","url":"https://www.mskcc.org/cancer-care/integrative-medicine/herbs/garlic"}],"tags":["complementary","supportive-care","evidence:insufficient"],"related":["ginkgo","echinacea"],"cancers":["gastric","colorectal"],"sections":["supportive-care","prevention","nutrition-lifestyle"],"technologies":["integrative-oncology","dietary-supplements-treatment-interactions"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":["b-toxicity-qol"],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"principle":"Allicin and other organosulphur compounds formed when garlic is crushed have antiplatelet and antimicrobial effects; processing changes their content substantially.","strengths":["Safe as food","Large population studies of prevention exist"],"limitations":["Prevention evidence mixed; no evidence of treatment effect","Bleeding risk with anticoagulants, low platelets and surgery","Can lower exposure to some drugs"]},"route":"/technologies/garlic-supplements/","neighbours":{"technology":[{"id":"berberine","kind":"technology","name":"Berberine","route":"/technologies/berberine/"},{"id":"dietary-supplements-treatment-interactions","kind":"technology","name":"Dietary supplements during cancer treatment: interactions and harms","route":"/technologies/dietary-supplements-treatment-interactions/"},{"id":"echinacea","kind":"technology","name":"Echinacea","route":"/technologies/echinacea/"},{"id":"integrative-oncology","kind":"technology","name":"Evidence-based integrative oncology","route":"/technologies/integrative-oncology/"},{"id":"ginkgo","kind":"technology","name":"Ginkgo biloba","route":"/technologies/ginkgo/"}],"cancer":[{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"},{"id":"gastric","kind":"cancer","name":"Gastric & gastro-oesophageal junction cancer","route":"/cancers/gastric/"}],"section":[{"id":"nutrition-lifestyle","kind":"section","name":"Diet, Exercise & Lifestyle","route":"/fronts/nutrition-lifestyle/"},{"id":"prevention","kind":"section","name":"Prevention & Risk","route":"/fronts/prevention/"},{"id":"supportive-care","kind":"section","name":"Supportive Care & Survivorship","route":"/fronts/supportive-care/"}],"bottleneck":[{"id":"b-toxicity-qol","kind":"bottleneck","name":"Toxicity and quality of life are undervalued","route":"/bottlenecks/b-toxicity-qol/"}]}}