How it works

Researchers have proposed several ways carnosine acts. Most of the evidence is from chemistry, cells and animals that lack serum carnosinase, so a mechanism shown in a dish is not shown in a person. Aldini and colleagues wrote in 2021 that the molecular mechanisms “are not yet clearly defined” (Free Radical Research 2021).

The pages below take each proposed mechanism in turn.

• pH buffering in muscleHow carnosine takes up hydrogen ions as working muscle acidifies, and how much of muscle buffering it accounts for.
• Antioxidant and metal bindingCarnosine reacts with reactive oxygen species and binds copper and zinc. What the laboratory evidence shows and what it does not.
• Anti-glycation and carbonyl quenchingThe hypothesis that carnosine traps reactive carbonyl compounds and so slows the formation of advanced glycation end products.
• Calcium handling in muscleLaboratory evidence that carnosine changes how muscle fibres respond to calcium, a proposed second mechanism for its effect on performance.
• Breakdown by carnosinaseThe two enzymes that break carnosine down, why humans differ from other mammals, and the link between the CNDP1 gene and kidney disease.