BCAAs (Branched-Chain Amino Acids): Evidence and Safety
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BCAAs (Branched-Chain Amino Acids): half-life, strengths and approval status

Amounts studied · Approval status · Half-life notes

What is BCAAs?

BCAAs are three essential amino acids, leucine, isoleucine and valine, named for their branched chemical structure. They make up about a quarter of the amino acids in complete proteins such as meat, eggs and milk. As a supplement they are taken to build muscle, reduce soreness and delay fatigue.

Also known as: branched-chain amino acids, leucine, isoleucine and valine, BCAA powder.

Amounts studied

ODS describes short studies of about 10 to 14 g a day of BCAAs during training, and says up to 20 g a day in divided servings appears safe. These are study protocols, not a recommendation.

Approval status and how it is used

It is sold in the US as a dietary supplement. Under the 1994 dietary supplement law (DSHEA), FDA does not approve dietary supplements before they are marketed, and the maker, not FDA, is responsible for safety and labeling. ODS says BCAAs make up about 14% to 18% of the amino acids in human muscle, and that eating complete proteins, or protein powders such as whey, already provides them.

What studies show, per ODS: little evidence that BCAAs improve endurance performance; several 3- to 6-week studies suggest 10 to 14 g a day might add to gains in muscle mass and strength, but overall the evidence is inconsistent that BCAAs build muscle beyond what enough high-quality protein does. ODS concludes that studies have not consistently shown BCAAs improve performance, build muscle or aid recovery. A 2017 review by Wolfe found no human studies measuring muscle protein building after BCAAs taken by mouth alone, and argued that BCAAs alone cannot drive lasting muscle growth because the other essential amino acids are also needed. A 2019 meta-analysis of 8 small studies (61 people) found less muscle soreness after exercise with BCAAs than with placebo.

Safety, per ODS: no safety concerns have been reported at 20 g a day or less for up to 6 weeks, and no adverse effects are known.

BCAAs half-life and time to peak

  • Half-lifeNot listed
  • Time to peak (Tmax)Not listed

We could not find a single published half-life or time to peak for BCAAs that applies to a supplement dose, so we do not list one.

How to track BCAAs in Dose Track

  1. Add BCAAs as a custom compound. Start typing its name and Dose Track fills in the details from its research library for you to check, and it sits next to everything else you take.
  2. Log each dose when you take it so your history shows exactly what you took and when.
  3. Set reminders on your own schedule, whether that is daily, weekly or every few days.
  4. Your log is stored on your phone and no account is needed. Data only leaves it for features you choose, like AI answers and lab reading.

How Dose Track handles peptides · Reconstitution calculator · Half-life calculator

Leucine (L-Leucine)L-leucine, branched-chain amino acid HMB (Beta-Hydroxy-Beta-Methylbutyrate)beta-hydroxy-beta-methylbutyrate, HMB-Ca Whey Proteinwhey protein isolate, whey concentrate

Frequently asked questions

What is the half-life of BCAAs?+
We could not find a single published half-life or time to peak for BCAAs that applies to a supplement dose, so we do not list one.
Do BCAAs build muscle?+
The evidence is weak. The NIH Office of Dietary Supplements says studies have not consistently shown that BCAAs build muscle beyond what enough high-quality protein does, and a 2017 review found no human studies measuring muscle protein building after BCAAs alone by mouth.
Do I need BCAAs if I eat enough protein?+
ODS says complete proteins from animal foods, combinations of plant proteins, and protein powders such as whey already supply BCAAs, and whey has more leucine than casein or soy.
Can I track BCAAs in Dose Track?+
Yes. BCAAs is in Dose Track's research library, so when you add it as a custom compound its details are filled in for you to check. You can then log each dose next to your other compounds, set reminders on your own schedule, and see your history next to your lab results. Your log is stored on your phone and no account is needed. Data only leaves it for features you choose, like AI answers and lab reading.

Sources

  1. NIH Office of Dietary Supplements. Dietary supplements for exercise and athletic performance, fact sheet for health professionals (updated April 1, 2024).
  2. Wolfe RR. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? J Int Soc Sports Nutr. 2017;14:30.
  3. Fedewa MV, et al. Effect of branched-chain amino acid supplementation on muscle soreness following exercise: a meta-analysis. Int J Vitam Nutr Res. 2019;89(5-6):348-356.
  4. FDA. Questions and answers on dietary supplements.

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