Clinical studies on BCAA supplements used 5 to 20 grams a day, or 5,000 to 20,000 milligrams, taken in one or two doses around training. The amino acids came in a ratio close to 2:1:1 leucine to isoleucine to valine, so a 10 gram dose carries about 5 grams of leucine, 2.5 grams of isoleucine and 2.5 grams of valine.
That is the dose question answered. The harder question is whether a separate BCAA product does anything a complete protein does not. For most people who already eat enough protein, the research says it adds little.
What BCAAs Are and Why Leucine Leads
You get BCAAs, or branched chain amino acids, from every protein you eat. They are three of the nine essential amino acids, which your body cannot make on its own. Leucine gets the most attention because it triggers the first step of muscle protein synthesis, the process that repairs and builds muscle after training. A 2021 review in the International Journal of Sport Nutrition and Exercise Metabolism describes that role. It also notes that BCAAs remain one of the most popular sports supplements.
BCAA Dosage by Goal
Your goal sets your dose. Each row below comes from a clinical trial, a meta analysis or a position stand, linked in the sections that follow.
| Goal | Dose studied | Timing | Source |
|---|---|---|---|
| Muscle protein synthesis after lifting | 5.6 g once (2.6 g leucine, 1.4 g isoleucine, 1.6 g valine) | Right after resistance exercise | Jackman et al., Frontiers in Physiology, 2017. 10 trained men |
| Soreness after squats | 100 mg per kg of body weight, once | Before exercise | Shimomura et al., Int J Sport Nutr Exerc Metab, 2010. 12 untrained women |
| Muscle damage after jump training | 20 g a day, 2:1:1 ratio | Twice daily for 12 days, plus 20 g before and after the session | Howatson et al., J Int Soc Sports Nutr, 2012. 12 trained men |
| Delayed onset muscle soreness | Up to 255 mg per kg a day | Before exercise, not only after | Weber et al., Amino Acids, 2021. 10 trials |
| Muscle building from protein meals | 700 to 3,000 mg leucine per serving | 20 to 40 g of protein every 3 to 4 hours | Jäger et al., ISSN position stand, 2017 |
BCAA dose by body weight, for women and men
Your body weight changes the amount, because several trials dosed per kilogram instead of using a flat number. Lighter people, including many women, land lower in the range. At 100 milligrams per kilogram, a 60 kilogram person takes about 6 grams and a 90 kilogram person takes about 9 grams. The top of the soreness research, 255 milligrams per kilogram, works out to about 15 grams and 23 grams for the same two people.
Do BCAAs Help Muscle Growth?
BCAAs alone switch on your muscle building, but only partway. In a 2017 trial in Frontiers in Physiology, 10 trained men drank 5.6 grams of BCAAs right after resistance exercise. Muscle protein synthesis ran 22 percent higher than with a placebo.
The same authors noted that this response was about 50 percent smaller than one previously reported for whey protein with a similar BCAA content. Their conclusion: BCAAs alone do not maximally stimulate muscle building after exercise.
Why three amino acids cannot do the job of nine
Your muscle is built from all nine essential amino acids. BCAAs supply three. A 2017 review in the Journal of the International Society of Sports Nutrition made this case directly. It concluded that the claim that BCAAs alone produce an anabolic, or muscle building, response in humans is unwarranted.
Do BCAAs Reduce Muscle Soreness?
Your best case for BCAAs is soreness, and the effect is modest. In a 2010 trial, 12 untrained women took 100 milligrams per kilogram of body weight before a squat session. Their soreness on days 2 and 3 was lower than with a placebo.
In a 2012 trial, trained men took 20 grams a day in a 2:1:1 ratio for 12 days around a bout of 100 drop jumps. The BCAA group showed less soreness and lower creatine kinase, a blood marker of muscle damage.
What the pooled studies show
Pooled results give you the wider view, and they are more mixed than single trials. A 2017 meta analysis of 8 trials in Nutrition found lower creatine kinase in the first 24 hours, with no significant difference in soreness. A 2021 meta analysis of 9 trials in Nutrients looked only at trained men. It found lower creatine kinase up to 48 hours and less soreness only within the first 24 hours.
A 2021 systematic review in Amino Acids covered 10 trials. Seven reported less soreness 24 to 72 hours after exercise. The clearest benefit came in trained people with mild to moderate muscle damage, at doses up to 255 milligrams per kilogram a day. The authors advised against taking BCAAs only after exercise.
Why Total Protein Matters More Than a BCAA Scoop
Your daily protein total does more work than any separate BCAA dose. The International Society of Sports Nutrition position stand puts 1.4 to 2.0 grams of protein per kilogram of body weight a day as enough for most people who exercise. It suggests 20 to 40 grams per serving, every 3 to 4 hours, with 700 to 3,000 milligrams of leucine in each.
Every complete protein, from meat, eggs and dairy to whey, already carries BCAAs. It also carries the six essential amino acids that BCAAs lack. Once that daily protein target is met, a BCAA product adds more of three amino acids the diet already supplies.
How Much BCAA Is in Whey Protein?
Your whey shake already carries a full BCAA dose. The 2017 Frontiers in Physiology trial put the typical BCAA content of 20 grams of whey protein at 5.6 grams, or about 28 percent. One ordinary serving of whey matches the BCAA dose that trial tested, with the other essential amino acids included.
How Much BCAA Is Too Much?
The doses in these studies keep you well below the one upper limit researchers have proposed. A 2012 study in the American Journal of Clinical Nutrition was run because no upper limit for leucine existed. It raised leucine intake step by step in 5 healthy young men.
Blood ammonia and plasma leucine rose above normal at intakes above 500 milligrams per kilogram a day. The authors suggested about 35 grams of leucine a day as a cautious upper limit. A 20 gram BCAA dose in a 2:1:1 ratio carries 10 grams of leucine.
Turn that into a total and you get about 70 grams of BCAAs a day, because leucine makes up half of a 2:1:1 blend. That 70 gram figure is our arithmetic, not a dose any study tested. For everyday use, the NIH Office of Dietary Supplements says up to 20 grams of BCAAs a day, split into doses, appears to be safe.
Who should avoid BCAA supplements
You should skip BCAAs entirely if you have either of two conditions. Maple syrup urine disease is an inherited disorder in which the body cannot break down leucine, isoleucine and valine, according to the NIH's MedlinePlus. Left untreated, it can lead to seizures, coma and death.
ALS, the nerve disease also called Lou Gehrig's disease, is the other clear caution. In a 1993 trial in Neurology, people with ALS took 24 grams of BCAAs a day or a placebo. After 126 patients had enrolled, deaths stood at 24 in the BCAA group and 13 on placebo, and the trial was stopped. If you manage any medical condition, ask your doctor before you add a BCAA supplement.
The verdict: studies used 5 to 20 grams of BCAAs a day, in a ratio close to 2:1:1. BCAAs alone produced about half the muscle building response of whey with a similar BCAA content. For most people, a complete protein that meets the daily target is the better use of the money, and it already contains the BCAAs.
BCAA Dosage FAQ
How many BCAAs are there?
There are three BCAAs: leucine, isoleucine and valine. All three are essential amino acids, so your body cannot make them and has to get them from food or supplements. The studies above used them in a ratio close to 2:1:1, with leucine as the largest share.
What is the maximum amount of BCAA per day?
You can take up to 20 grams a day, split into doses, which the NIH Office of Dietary Supplements says appears to be safe. The only ceiling researchers have proposed is for leucine, about 35 grams a day. At a 2:1:1 ratio that works out to roughly 70 grams of total BCAAs, by our math rather than any study's.
Can you overdose on BCAAs?
The doses in sports studies stay far below the point where problems showed up, but very high intakes do change your blood chemistry. In the leucine study, blood ammonia rose above normal at intakes above 500 milligrams per kilogram a day. People with maple syrup urine disease or ALS face specific risks, covered in the section above.
How many calories are in BCAA?
You get about 40 calories from a 10 gram dose if you count BCAAs like protein, at the standard 4 calories per gram used on U.S. food labels. Your label may not list protein at all, because FDA rules bar a product made only of individual amino acids from declaring it. Check the calories line on the Supplement Facts panel for your product's own figure.
How many capsules or scoops of BCAA should I take?
Divide your daily dose in grams by the grams of BCAAs in one capsule or one scoop, which you can work out from the serving size on your label. If a label shows 500 milligrams per capsule, a 5 gram dose takes 10 capsules. If one scoop carries 5 grams, a 10 gram dose is two scoops.
Should you take BCAAs every day?
You can, and several trials gave them daily. The NIH notes studies lasting about 3 to 6 weeks at about 10 to 14 grams a day. If you already meet your daily protein target, though, the research above suggests a daily BCAA dose adds little.
How Much BCAA Should You Take?
For muscle growth, put your effort into total protein instead of a separate BCAA dose. Aim for 1.4 to 2.0 grams of protein per kilogram of body weight a day, split into servings of 20 to 40 grams.
For soreness after hard training, the studied range is about 5 to 20 grams of BCAAs a day, taken before exercise as well as after. Expect a small effect. The clearest results came in trained people.
At BioHealth Nutrition, the BCAAs come inside the protein itself. Our whey isolate protein powders fit the serving sizes above.
A scoop of our pasture fed whey protein isolate carries 27 grams of protein with 1 to 2 grams of carbs. Isolate is filtered to remove most of the lactose found in regular whey, a difference covered in our guide to whey isolate vs whey protein.
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Recovery products are grouped in our mobility and recovery supplements collection.
Related reading: how whey compares with collagen as a daily protein source, in collagen peptides vs whey protein.
Sources. Jackman SR. et al., Branched Chain Amino Acid Ingestion Stimulates Muscle Myofibrillar Protein Synthesis following Resistance Exercise in Humans, Frontiers in Physiology, 2017. Wolfe RR., Branched chain amino acids and muscle protein synthesis in humans: myth or reality?, Journal of the International Society of Sports Nutrition, 2017. Shimomura Y. et al., Branched chain amino acid supplementation before squat exercise and delayed onset muscle soreness, International Journal of Sport Nutrition and Exercise Metabolism, 2010. Howatson G. et al., Exercise induced muscle damage is reduced in resistance trained males by branched chain amino acids, Journal of the International Society of Sports Nutrition, 2012. Rahimi MH. et al., Branched chain amino acid supplementation and exercise induced muscle damage in exercise recovery: a meta analysis of randomized clinical trials, Nutrition, 2017. Khemtong C. et al., Does Branched Chain Amino Acids (BCAAs) Supplementation Attenuate Muscle Damage Markers and Soreness after Resistance Exercise in Trained Males?, Nutrients, 2021. Weber MG. et al., The use of BCAA to decrease delayed onset muscle soreness after a single bout of exercise: a systematic review and meta analysis, Amino Acids, 2021. Plotkin DL. et al., Isolated Leucine and Branched Chain Amino Acid Supplementation for Enhancing Muscular Strength and Hypertrophy: A Narrative Review, International Journal of Sport Nutrition and Exercise Metabolism, 2021. Jäger R. et al., International Society of Sports Nutrition Position Stand: protein and exercise, Journal of the International Society of Sports Nutrition, 2017. Elango R. et al., Determination of the tolerable upper intake level of leucine in acute dietary studies in young men, American Journal of Clinical Nutrition, 2012. The Italian ALS Study Group, Branched chain amino acids and amyotrophic lateral sclerosis: a treatment failure?, Neurology, 1993. National Institutes of Health, Office of Dietary Supplements, Dietary Supplements for Exercise and Athletic Performance, fact sheet for health professionals, updated 2024. National Library of Medicine, MedlinePlus Genetics, Maple syrup urine disease. U.S. Food and Drug Administration, 21 CFR 101.36, nutrition labeling of dietary supplements, and 21 CFR 101.9(c)(1), calorie factors.
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