Forms and Doses

Carnosine research uses several different substances, and they are not interchangeable. Sports studies mostly give beta-alanine and measure the carnosine that muscle makes from it. Gut studies give zinc-L-carnosine. Eye studies give N-acetylcarnosine drops. Metabolic and brain trials give carnosine itself by mouth. The pages below describe each form and the evidence on how it is absorbed.

• Carnosinase and absorptionWhat happens to carnosine taken by mouth in people: fast breakdown by serum carnosinase, and what the absorption studies show.
• Beta-alanine, the precursorBeta-alanine is one half of carnosine. Supplementing it raises muscle carnosine. Loading, washout, the tingling side effect and the sports evidence.
• Zinc-L-carnosine (polaprezinc)A zinc complex of carnosine, approved as a gastric ulcer medicine in Japan in 1994 and sold as a supplement elsewhere. Chemistry, history and the trials.
• N-acetylcarnosineCarnosine with an acetyl group added, used in eye drops for cataract. The trials, the independent reviews, and what regulators say.
• Topical gel and skinCarnosine applied to the skin as a gel or cream. What has been published, and what has not.
• Anserine and related dipeptidesCarnosine's relatives: anserine, balenine (ophidine), homocarnosine and carcinine. Where each occurs and how they differ.
• Doses used in published trialsThe doses that researchers used in each study in the database, by species. Not a dosing guide.
• Safety and interaction dataWhat published trials and reviews report about adverse events with carnosine, beta-alanine and zinc-L-carnosine.