{"ok":true,"entry":{"slug":"oyster-extract","kind":"supplement","name":"oyster extract","aliases":["oyster peptide","zinc-rich oyster powder"],"brands_sg":[],"class":"marine extract","tags":["mens-health","energy"],"use_for":"human rcts cover child growth and liver enzymes","use_after":null,"use_duration":"the growth trials ran 24 weeks; the liver trial 12","take_with":null,"pros":["oysters carry more zinc per serving than any food","two 24-week child-growth rcts (n=80 each) were positive","no serious adverse events in those growth trials"],"cons":["review: 10 animal studies, 1 rct — certainty very low","the human trials are in children and in drinkers","mild rash led to one drop-out in a growth trial"],"dose_note":"the two child-growth trials gave 500 mg a day of a fermented oyster extract for 24 weeks; the adult liver trial ran 12 weeks and its abstract states no milligram dose","dosage":{"ul":null,"unit":"mg","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":["singapore caps zinc in health supplements at 15 mg a day for general adult use — relevant to zinc-labelled oyster products","the adult upper limit for zinc is 40 mg a day at 19+ years (nih ods)","shellfish — two events of mild rash, possibly related, occurred in a growth trial","the growth trials were in children aged 6–9, not adults"],"clashes":[{"src":["ods_zinc_meds","ods_zinc_food"],"note":"nih ods lists these as zinc interactions; oysters are the richest food source of zinc","with":"quinolone or tetracycline antibiotics, penicillamine"}],"sources":[{"id":"oyster_growth2026","url":"https://europepmc.org/article/PMC/PMC13243516","label":"Fermented oyster extract promotes height growth in children with mild short stature: a randomized, double-blind, placebo-controlled trial (Kim et al., Nutr Res Pract 2026)","quote":"subjects received FGO (n = 40) or placebo (n = 40) once daily (500 mg/day) for 24 weeks … the FGO group showed significant improvements in height, height SD score, and height velocity (all P < 0.001)","accessed":"2026-08-27"},{"id":"oyster_growth2026b","url":"https://europepmc.org/article/PMC/PMC13125082","label":"Fermented oyster extract improves linear growth in children with idiopathic short stature: a randomized, double-blind, placebo-controlled trial (Nagahawatta et al., Prev Nutr Food Sci 2026)","quote":"80 children aged 6－9 years … No serious adverse events or clinically meaningful laboratory abnormalities were observed; however, two events of mild rash, possibly related to FGO, led to one drop-out","accessed":"2026-08-27"},{"id":"oyster_liver2015","url":"https://europepmc.org/article/PMC/PMC4509380","label":"Improvement of liver function by the administration of oyster extract as a dietary supplement to habitual alcohol drinkers: a pilot study (Osaki et al., Exp Ther Med 2015)","quote":"84 adults who had an alcohol-drinking habit and marginally high serum GGT levels were enrolled … A significant between-group difference in the change of mean GGT from baseline was, however, found at week 12 (P=0.049)","accessed":"2026-08-27"},{"id":"oyster_ald2026","url":"https://europepmc.org/article/PMC/PMC13035715","label":"Hepatoprotective effects of oyster-derived bioactive compounds in alcoholic liver disease: a systematic review (Chen et al., Front Gastroenterol 2026)","quote":"Eleven studies met the inclusion criteria, comprising ten animal studies and one randomized controlled trial … the certainty of evidence ranged from very low to low, reflecting … limited human data","accessed":"2026-08-27"},{"id":"ods_zinc_food","url":"https://web.archive.org/web/2026/https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/","label":"NIH ODS — Zinc (Health Professional), read via the archive.org capture because ods.od.nih.gov returns 403 to direct fetches","quote":"Oysters contain more zinc per serving than any other food … Oysters, Eastern, farmed, raw, 3 ounces — 32 mg, 291% DV","accessed":"2026-08-27"},{"id":"ods_zinc_ul","url":"https://web.archive.org/web/2026/https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/","label":"NIH ODS — Zinc (Health Professional), Table 3, read via the archive.org capture because ods.od.nih.gov returns 403 to direct fetches","quote":"Table 3: Tolerable Upper Intake Levels (ULs) for Zinc in Milligrams (mg) … 19+ years — 40 mg male, 40 mg female, 40 mg pregnancy, 40 mg lactation","accessed":"2026-08-27"},{"id":"ods_zinc_meds","url":"https://web.archive.org/web/2026/https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/","label":"NIH ODS — Zinc (Health Professional), read via the archive.org capture because ods.od.nih.gov returns 403 to direct fetches","quote":"Zinc may interact with certain medications, such as quinolone antibiotics, tetracycline antibiotics, and penicillamine","accessed":"2026-08-27"},{"id":"hsa_hs_zinc","url":"https://file.go.gov.sg/hsa-hs-guidelines.pdf","label":"HSA — Health Supplements Guidelines, GL-CHPB-3-001 Rev 020 (Jan 2026), Table 5: Minerals Limits","quote":"Table 5: Minerals Limits — Nutrient / Maximum Daily Limit … Zinc 15 mg","accessed":"2026-08-27"},{"id":"hsa_prohibited_2025","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, GL-CHPB-1-012 Rev 001 (Oct 2025)","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 [oyster / Crassostrea spp. not listed in Annex A or B]","accessed":"2026-08-27"}],"brand_certs":null,"updated_at":"2026-08-29T16:16:27.496708+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."}