Branched-chain amino acid (BCAA) supplements may not be as effective for building muscle mass as other supplements containing all eight Essential Amino Acids, a recent study showed.

The June 2017 study, published in the journal Frontiers in Physiology, demonstrated decreased levels of essential amino acids in athletes taking BCAA supplements without any other forms of supplementation. These findings suggest that other supplements containing complete proteins likely stimulate maximum muscle growth better than BCAAs alone.

What are BCAAs?

BCAAs are essential nutrients found in protein-rich foods like meat, dairy, and legumes, according to WebMD.

There are three BCAAs: leucine, isoluceine, and valine. Proteins comprised of amino acids like these are widely known to aid muscle growth.

A number of brands have jumped on the BCAA bandwagon, offering supplement products ranging from powders to capsules in both small- and economy-sized packages. They’re available in vitamin- and supplement-oriented stores like Vitamin Shoppe and GNC, and also online on brand websites and other sites like

Uses for BCAAs extend beyond exercising, according to WebMD. They can be used to improve concentration and stave off fatigue, and they’re even used to treat certain conditions like Lou Gehrig’s disease and acute hepatic encephalopathy (head swelling) caused by liver disease.

Why do athletes take supplements like BCAAs?

Taking supplements to aid muscle growth first became popular during the 1970s and 1980s, especially amid the birth of modern bodybuilding and newer marketing techniques.

Now, performance-enhancing supplements are more popular than ever before, with many athletes and bodybuilders claiming to achieve better and faster muscle growth through taking supplements.

In an article for, Layne Norton, PhD, said “I believe BCAAs are especially helpful for maintaining muscle mass while on a calorie-deficit diet. They're particularly useful for bodybuilding competitors who take their physiques to the lean extreme.”

What are some alternatives?

Although BCAAs likely benefit muscle growth in some ways, research has suggested that other supplements containing complete sets of essential amino acids can better help athletes achieve optimum muscle growth, in addition to a protein-rich diet.

Products containing essential amino acids (frequently abbreviated “EAAs”) are widely available in vitamin and supplement stores and online as well. Like BCAAs, they come in forms like powders and capsules, and are also popular in the fitness and bodybuilding communities.

Be sure to consult your doctor prior to any dietary changes, new exercise regimens, or initiation of supplements.