Beta-alanine, the precursor

Beta-alanine is one of the two amino acids in carnosine. Muscle makes carnosine from beta-alanine and histidine, and beta-alanine supply is the limiting step (Open Heart review 2014). Most of the sports literature on “carnosine” is in fact beta-alanine research. The study pages on this site mark those entries with the tag “beta-alanine (carnosine precursor)”.

Loading

Harris 2006 showed that beta-alanine taken by mouth raises human muscle carnosine. Hill 2007 measured the rise over 4 and 10 weeks. In the trials reviewed by Stellingwerff 2020, 3 to 6 g a day for four or more weeks raised muscle carnosine by about 30 to 50 per cent. The Australian Institute of Sport fact sheet describes the protocol used in research as 6.4 g a day split over four doses for at least four weeks, then about 1.2 g a day to maintain (AIS). These are the doses researchers used, not a recommendation.

Washout

Muscle carnosine falls slowly after loading stops, about 2 per cent a week (Baguet 2009).

Side effect

Paraesthesia, a tingling of the skin, is the common side effect, at single doses above about 800 mg. A meta-analysis of 101 human studies found no other adverse effects reported more often than with placebo, and put the odds of paraesthesia at about nine times placebo (Dolan 2019).

Performance evidence

A 2017 meta-analysis of 40 studies found a small benefit for exercise lasting 30 seconds to 10 minutes and none for shorter or longer efforts (Saunders 2017). See Exercise and muscle.

In horses

Dunnett and Harris gave beta-alanine with histidine to horses and measured muscle carnosine (Dunnett 1999). A 2024 study tested beta-alanine in Yili racehorses (Li 2024). See Horses and Horse racing and sport rules.

Status

Beta-alanine is not named on the WADA Prohibited List. In Australia, beta-alanine is not a permitted substance in formulated supplementary sports foods under Standard 2.9.4, and it has no entry as an active ingredient in the TGA Permissible Ingredients Determination. See Status in Australia.