Leucic Acid

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.

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.

The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what effects leucic acid has on your body, and how strong these effects are.

Grade	Level of Evidence [show legend]
	Robust research conducted with repeated double-blind clinical trials
	Multiple studies where at least two are double-blind and placebo controlled
	Single double-blind study or multiple cohort studies
	Uncontrolled or observational studies only

Level of Evidence ? The amount of high quality evidence. The more evidence, the more we can trust the results.	Outcome	Magnitude of effect ? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.	Consistency of research results ? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.	Notes
	Lean Mass	Minor	- See study	An increase in lean mass has been noted in the legs of soccer players to the degree of 0.4kg over 4 weeks; this study currently stands alone
	Muscle Soreness	Minor	- See study	A decrease in muscle soreness has been noted in the one study conducted in athletes (when measured at week 4 only) to the degree of around 23%, but muscle soreness was not overly high in the study to begin with
	Weight	Minor	- See study	The lone study using leucic acid in athletes has noted a minor but statistically significant increase in weight, attributable to lean mass (muscle plus water; bone mass unchanged)
	Anaerobic Running Capacity	-	- See study	No significant influence on anaerobic running capacity
	Bone Mineral Density	-	- See study	No significant alterations in bone mineral density
	Fat Mass	-	- See study	No significant interaction between leucic acid and body fat has yet to be detected
	Power Output	-	- See study	Power output as assessed by jumping tasks and weightlifting is unaffected