C15:0 (Pentadecanoic Acid) Supplements UK 2026: Buying Guide

Evaluating C15:0 products for metabolic and longevity claims.

🐢 This article contains affiliate links. We may earn a small commission at no extra cost to you. These links do not influence our editorial judgements. See the full disclosure.

TL;DR: C15:0 is an odd-chain saturated fatty acid with interesting cell-system and observational research, but human clinical trials are still early. Products typically provide 100–200 mg/day. Look for pure pentadecanoic acid, not a generic fatty-acid blend.

🐢 Tortoise Wisdom"C15:0 has buzz, but it is not yet backed by large human outcome trials. Treat it as experimental, not essential."

Looking for a product? Here is an independently chosen Amazon option that matches the criteria in this guide.

View on Amazon →

1. What Is C15:0?

C15:0, or pentadecanoic acid, is found in dairy fat and some fish. Researchers have proposed it as an essential fatty acid because low plasma levels correlate with worse metabolic health. Read our full Urolithin A and C15:0 evidence review.

2. Dose and Food Sources

  • Study dose: typically 100–200 mg/day of pure C15:0.
  • Food: full-fat dairy is the main dietary source, but most people do not get 100+ mg/day.

3. Buying Checklist

  • Ingredient: should list 'pentadecanoic acid' or 'C15:0'.
  • Amount per serving: 100–200 mg is typical.
  • Source: check whether it is vegan (synthetic) or dairy-derived if you have allergies.
  • Form: capsules are standard.

4. Safety

Short-term safety data are reassuring, but long-term effects are unknown. Because it is a saturated fat, people with lipid disorders should speak to a clinician before use.