L-carnosine, not to be confused with L-carnitine, is a substance manufactured in the human body, made by combining the amino acids alanine and histidine. The highest levels of carnosine are found in the brain and nervous system, the lens of the eye, and skeletal muscle tissue. Its exact function in the body is not known.

The body manufactures carnosine from common dietary proteins, and for this reason there is no daily requirement of this substance.