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Oyster extract

Supplement marine extract men's healthenergy
Aka: oyster peptide, zinc-rich oyster powder
Not medical advice. Check with your doctor or pharmacist before you start, stop or change the timing of anything you take.
How to use
What it’s for
Human RCTS cover child growth and liver enzymes
Studied for
The growth trials ran 24 weeks; the liver trial 12
Pros & cons
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
Sources
  1. 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) · read 2026-08-27
    what it says
    “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)”
  2. 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) · read 2026-08-27
    what it says
    “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”
  3. 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) · read 2026-08-27
    what it says
    “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)”
  4. Hepatoprotective effects of oyster-derived bioactive compounds in alcoholic liver disease: a systematic review (Chen et al., Front Gastroenterol 2026) · read 2026-08-27
    what it says
    “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”
  5. NIH ODS — Zinc (Health Professional), read via the archive.org capture because ods.od.nih.gov returns 403 to direct fetches · read 2026-08-27
    what it says
    “Oysters contain more zinc per serving than any other food … Oysters, Eastern, farmed, raw, 3 ounces — 32 mg, 291% DV”
  6. NIH ODS — Zinc (Health Professional), Table 3, read via the archive.org capture because ods.od.nih.gov returns 403 to direct fetches · read 2026-08-27
    what it says
    “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”
  7. NIH ODS — Zinc (Health Professional), read via the archive.org capture because ods.od.nih.gov returns 403 to direct fetches · read 2026-08-27
    what it says
    “Zinc may interact with certain medications, such as quinolone antibiotics, tetracycline antibiotics, and penicillamine”
  8. HSA — Health Supplements Guidelines, GL-CHPB-3-001 Rev 020 (Jan 2026), Table 5: Minerals Limits · read 2026-08-27
    what it says
    “Table 5: Minerals Limits — Nutrient / Maximum Daily Limit … Zinc 15 mg”
  9. HSA — Guidelines on Prohibited and Restricted Ingredients in Health Supplements and Traditional Medicines, GL-CHPB-1-012 Rev 001 (Oct 2025) · read 2026-08-27
    what it says
    “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]”
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Updated 2026-08-29. Every line above traces to a numbered source. Kozen-X is not a medical device and does not give medical advice. It lists what published sources have written down — nothing more. A pair not listed is unrecorded, not cleared. Before you start, stop or re-time anything, talk to your doctor or pharmacist.