The branched-chain amino acids (BCAA) are three essential amino acids: leucine, isoleucine, and valine. BCAAs cannot be manufactured by the human body, and are therefore nutritionally essential.

BCAAs act as a fuel source for skeletal muscle during times of trauma or stress, help prevent catabolism (the breakdown of muscle for energy), while encouraging protein synthesis. BCAAs have been studied as a possible aid for severe burns, trauma and sepsis.

Branched-chain amino acids are especially popular among athletes and strength trainers for their anti-catabolic properties.

When To Take BCAA Supplements

Branched-chain amino acid supplements are available in caplet, tablet, and powder form. Use as directed. Consult your physician before taking a BCAA supplement.

BCAA supplements should not be taken by those who are pregnant/nursing, or by individuals with any serious conditions, including those of the kidney or liver. BCAAs should not be consumed in conjunction with alcohol, and care should be taken when taking in conjunction with anti-depressants (consult your physician).

Efficacy: There currently is no scientific evidence to support the claim that increasing protein or amino acid intake through supplementation will enhance metabolic efficiency and increase muscle mass.2,11 While some researchers have reported improvement in mental performance and ratings of perceived exertion,3 most studies fail to demonstrate any improvement in exercise following BCAA oral supplementation.11-14

Adverse effects: Excess amino acids result in the production of urea, which is then eliminated in the urine through various processes which increase the loss of water. Excessive supplementation can lead to dehydration, gout, liver and kidney damage, calcium loss and impaired absorption of essential amino acids.2 BCAA supplementation may cause bloating, water loss and diarrhea. The resulting dehydration may result in impaired exercise capacity, muscle cramping and an inability to regulate body temperature. Extreme dehydration can result in hallucinations or heat stroke.