C15:0 / Pentadecanoic acid (Fatty15)
An odd-chain saturated fatty acid that may be the first essential fatty acid identified in 90 years. Emerging evidence; not yet established.
Early human trials and biomarker work positive: improved liver function, red cell membrane integrity, inflammatory markers, modest lipid effects. The 'essential fatty acid' framing is contested — not yet established by mainstream nutritional science. Effects: 12+ weeks for biomarkers.
C15:0 (pentadecanoic acid) is a saturated fatty acid found in whole-fat dairy. Researcher Stephanie Venn-Watson and team proposed in 2020 that low C15:0 levels may underlie a 'Cellular Fragility Syndrome' that accelerates aging, and that supplementation reverses biomarker changes associated with metabolic decline. The branded form (Fatty15) is C15:0 in pure form. Early human trials are showing improvements in liver fat, red blood cell membrane integrity, and inflammatory markers. The claim that C15:0 is 'the first essential fatty acid discovered since omega-3 in the 1930s' is bold and not universally accepted. Treat as promising-but-emerging.
- Form
- Fatty15 (branded pure C15:0). Generic versions becoming available. Or consume whole-fat dairy.
- Dose
- 100 mg/day (the Fatty15 dose). Up to 300 mg/day in some emerging research.
- Timing
- With a meal. Once daily.
- Schedule
- Daily.
- Side effects
- Generally well-tolerated. Mild GI upset rare.
- Interactions
- No established interactions. Limited data.
- Contraindications
- Pregnancy / lactation — limited safety data. Active liver disease (caution).
- Lab markers
- C15:0 in red blood cell membrane (specialty labs offer this — useful baseline + follow-up). Liver enzymes if tracking liver outcomes.
- Food sources
- Whole-fat dairy (butter, full-fat milk, full-fat yogurt, cheese) is the primary food source. Some grass-fed beef. The shift away from full-fat dairy in modern diets may be why C15:0 levels have dropped at population scale.
Pairs with
Omega-3 fish oil (complementary fatty acid). Generally no established synergies.
within Fatty acids