{"ok":true,"entry":{"slug":"feverfew","kind":"supplement","name":"feverfew","aliases":["Tanacetum parthenium"],"brands_sg":["Swanson Vitamins","Nature's Way","NOW Foods","Vitacost","Oregon's Wild Harvest"],"class":"botanical","tags":["general"],"use_for":"migraine prevention — mixed results in small studies","use_after":null,"use_duration":null,"take_with":null,"pros":["some research points to fewer migraine attacks"],"cons":["results are mixed across small studies","dose and plant source differ between studies","ragweed sensitivity can mean an allergic reaction"],"dose_note":"the studies reviewed used different plant sources and dosage levels","dosage":{"ul":null,"unit":null,"fda_dv":null,"rda_ai":null,"ul_status":"none_established","population":"general adult","hsa_max_daily":null},"ul_status":"none_established","sg_class":null,"cautions":["ragweed and related plants — allergic reactions reported in sensitive people","pregnancy — NCCIH says feverfew may affect uterine contractions","blood clotting — NCCIH says feverfew may slow it"],"clashes":[{"src":["nccih_feverfew_safety"],"note":"NCCIH says feverfew may interact with some medicines used for migraine","with":"migraine medicines"}],"sources":[{"id":"nccih_feverfew","url":"https://www.nccih.nih.gov/health/feverfew","label":"NIH NCCIH — Feverfew: Usefulness and Safety (last updated February 2025), 'How Much Do We Know?' and 'What Have We Learned?'","quote":"Some research suggests that feverfew may help prevent migraine headaches, but results have been mixed … The studies, which were small and used different sources and dosage levels of feverfew, showed inconsistent findings","accessed":"2026-08-27"},{"id":"nccih_feverfew_safety","url":"https://www.nccih.nih.gov/health/feverfew","label":"NIH NCCIH — Feverfew: Usefulness and Safety, 'What Do We Know About Safety?'","quote":"People who are sensitive to ragweed and related plants may have allergic reactions to feverfew … Feverfew may slow blood clotting … Feverfew may interact with some medicines, including those used for migraine … Do not take feverfew while pregnant","accessed":"2026-08-27"},{"id":"hsa_hs","url":"https://file.go.gov.sg/hsa-hs-guidelines.pdf","label":"HSA — Guidelines on health supplements (Singapore), maximum daily limits Tables 4–5","quote":"Table 4: Vitamins Limits … Nutrient Maximum Daily Limit … Table 5: Minerals Limits","accessed":"2026-08-27"},{"id":"hsa_pr","url":"https://file.go.gov.sg/hsa-chp-prohibited-restricted-ing-guidelines.pdf","label":"HSA — Guidelines on prohibited and restricted ingredients in health supplements and traditional medicines (Oct 2025), Annex A/B","quote":"The objective of this guideline is to highlight the substances of concern when used in HS and TM and is not meant to be an exhaustive list.","accessed":"2026-08-27"},{"id":"iherb_sg","url":"https://sg.iherb.com/c/feverfew","label":"iHerb Singapore — Feverfew: Leaf Extract Capsules for Head Comfort category page (default best-selling order)","quote":"Feverfew: Leaf Extract Capsules for Head Comfort","accessed":"2026-08-27"}],"brand_certs":null,"updated_at":"2026-08-29T16:16:19.87501+08:00"},"disclaimer":"kozen-x is not a medical device and does not give medical advice. it lists what published sources have written down. absence of a record is not the same as safe."}