How we rate
“Strong” = several concordant meta-analyses or systematic reviews. “Moderate” = one synthesis, or several controlled trials. “Limited” = early trials only. The rating is about the quality of the studies, not about how useful the supplement is.
BCAA / Essential Amino Acids
Three amino acids (leucine, isoleucine, valine) taken around exercise: they slightly reduce muscle soreness and markers of muscle damage, but alone, they stimulate muscle protein synthesis for less time than a real protein.
Benefits
- Reduces muscle soreness up to 96 hours after intense exercise and lowers creatine kinase, a marker of muscle damage (2024 meta-analysis), with a clearer effect at higher doses and longer supplementation durations
- Across 25 studies and 479 participants, fewer markers of muscle damage and muscle soreness 24 to 48 hours after intense exercise, with a dose-dependent effect
- In resistance-trained men, reduces creatine kinase up to 48 hours after the training session and muscle soreness within 24 hours (meta-analysis of randomized trials)
- Before an endurance effort, 20 g one hour before prolonged time to exhaustion from 46.6 to 50.4 minutes in 16 distance runners
- After a training session, 5.6 g of BCAAs alone increase muscle protein synthesis by 22% compared to placebo
- In 106 cirrhosis patients with muscle wasting, 7.2 g per dose over the long term improved muscle mass, strength, and function, with fewer complications
Precautions
Across 25 studies, BCAAs did not accelerate strength recovery after intense exercise, even when muscle soreness decreased. On performance and body composition, benefits are negligible according to the systematic review conducted in athletes, and results are inconsistent in endurance. Alone, BCAAs are not enough to build muscle: a review considers this idea unjustified, due to the lack of the other essential amino acids, and in elderly men, 6 g of BCAAs stimulate muscle protein synthesis for less time than 30 g of milk protein. In basketball players, they did not accelerate recovery after sprints with changes of direction.
Recommended dosage
5.6 to 6 g after the session in trials on muscle protein synthesis, 20 g one hour before an endurance effort, up to 255 mg per kilo per day against muscle soreness, preferably taken before exercise.
How to take it
- Before rather than after: in a pilot trial, BCAAs taken before eccentric exercise reduced muscle soreness and muscle damage better than intake afterwards.
- Dose against muscle soreness: up to 255 mg per kilo per day in the meta-analysis on muscle soreness, in trained athletes, after mild to moderate muscle damage.
- Over several days: in the 2024 meta-analysis, higher daily doses and longer supplementation periods yielded better results.
- For endurance: 20 g one hour before a graded treadmill test prolonged the effort by nearly 4 minutes in 16 runners, with less serotonin in the blood.
- It is not a complete protein: 5.6 g of BCAAs alone stimulate muscle protein synthesis (+22%), but a review considers the idea that they are sufficient without the other essential amino acids to be unjustified.
- With carbohydrates: BCAAs and carbohydrates taken after the session increased muscle protein synthesis by about 15% compared to carbohydrates alone.
Did you know?
In 45 older men, 6 g of BCAA increased muscle protein synthesis within two hours of intake, just like 30 g of milk protein — but between two and five hours, only the milk protein still kept it elevated.
What the studies say
This meta-analysis shows that BCAA supplementation significantly reduces markers of muscle damage (creatine kinase) immediately and 72 hours after intense exercise. It also significantly decreases delayed onset muscle soreness (DOMS) up to 96 hours after exertion. Higher daily and total dosages, as well as longer supplementation periods, are associated with better effects. In conclusion, BCAAs can be useful for reducing creatine kinase and DOMS after intense exercise.
Salem A, Ben Maaoui K, Jahrami H, AlMarzooqi MA, Boukhris O, Messai B, Clark CCT, Glenn JM, Ghazzaoui HA, Bragazzi NL, Ammar A, Trabelsi K, Chtourou H. — Sports medicine - open (2024) — View the source study
Pairs well with
- Creatine monohydrateBCAAs (particularly leucine) are associated with stimulating muscle protein synthesis (BCAA 3, 6, 7), whilst creatine monohydrate may complement this action by having potential anti-catabolic effects that reduce muscle protein breakdown (Creatine 5), suggesting a synergistic effect in supporting muscle health.
- Whey proteinWhey protein is a rich source of essential amino acids (EAAs) and BCAAs, which stimulate muscle protein synthesis (Whey 3, 7). Enriching a mixture of EAAs (whose composition is based on whey protein) with leucine (a BCAA) can specifically enhance muscle protein synthesis in older adults (Whey 6), suggesting that combining these supplements offers a benefit in optimising muscle anabolism.
For information only: not a substitute for medical advice. Dietary supplements are not a replacement for a varied, balanced diet. Learn more