Leucic Acid

Last Updated: September 28 2022

Leucic acid (also known as α-hydroxyisocaproic acid or HICA) is a leucine metabolite touted to have anabolic properties. Although it appears to be effective following oral supplementation, comparisons to leucine or HMB do not exist.

Leucic Acid is most often used for


Leucic acid (synonymous with the term α-hydroxyisocaproic acid and the latter's acronym HICA) is a metabolite of the branched chain amino acid known as leucine; leucine initially goes into one of two metabolic pathways (KIC or HMB) and then some of the KIC is further converted into HICA.

HICA is claimed to be an anti-catabolic and anabolic agent similar to HMB. The limited evidence that exists right now (literally one study in athletes and a mention of a pilot study conducted by the same researchers) suggests that there is benefit, but beyond needing replication this study is also confounded.

Although it would be imprudent to say that HICA is ineffective (which it does not appear to be) and similarly imprudent to say that it is worse than HMB or leucine, due to the lack of comparative data between HICA and HMB/leucine the question of 'which one to use' cannot be answered and we have no indication if HICA is better or worse than the other options.

HICA holds some promise for future research to tackle, but currently does not have enough evidence to support its usage as a supplement; it may simply be a more expensive and equally effective leucine.

What else is Leucic Acid known as?
Note that Leucic Acid is also known as:
  • Alpha-Hydroxy-isocaproic acid
  • DL-alpha-Hydroxy-isocaproic acid
  • HICA
Leucic Acid should not be confused with:
Dosage information

The only human evidence currently uses a daily dose of 1,500mg HICA, split into three divided doses of 500mg. There is not enough evidence to suggest if this is the optimal dose nor is there evidence to assess the comparative potency of HICA against leucine or HMB supplementation.

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1.^Staten MA, Bier DM, Matthews DERegulation of valine metabolism in man: a stable isotope studyAm J Clin Nutr.(1984 Dec)
2.^BLANCHARD M, GREEN DE, et all-Hydroxy acid oxidaseJ Biol Chem.(1946 Apr)
3.^Broadbent JR, Gummalla S, Hughes JE, Johnson ME, Rankin SA, Drake MAOverexpression of Lactobacillus casei D-hydroxyisocaproic acid dehydrogenase in cheddar cheeseAppl Environ Microbiol.(2004 Aug)
4.^Sakko M, Tjäderhane L, Sorsa T, Hietala P, Järvinen A, Bowyer P, Rautemaa R2-Hydroxyisocaproic acid (HICA): a new potential topical antibacterial agentInt J Antimicrob Agents.(2012 Jun)
7.^Hoffer LJ, Taveroff A, Robitaille L, Mamer OA, Reimer MLAlpha-keto and alpha-hydroxy branched-chain acid interrelationships in normal humansJ Nutr.(1993 Sep)
9.^Jakobs C, Sweetman L, Nyhan WLHydroxy acid metabolites of branched-chain amino acids in amniotic fluidClin Chim Acta.(1984 Jul 16)