Pentadecanoic Acid C15:0 Test

Pentadecanoic acid (C15:0) is an odd-chain, saturated fatty acid (formula CH₃(CH₂)₁₃COOH) most commonly found in dairy fat, certain fish, and ruminant-derived foods. Unlike even-chain fats, it can’t be synthesised de novo in significant amounts by the human body, so circulating levels serve as a biomarker of dietary dairy intake. Emerging research also links higher C15:0 levels with favourable metabolic profiles—lower risk of type 2 diabetes and better insulin sensitivity—making it a useful marker in advanced nutritional and metabolic testing.