BCAAs: wonder supplement or clever marketing?

As a sports nutrition coach, I frequently get asked whether BCAAs are necessary for muscle growth and recovery. The supplement industry has placed these amino acids on a pedestal as the solution for better performance. But what does scientific research actually say about it? Spoiler alert: it's more nuanced than the shiny tubs in the gym suggest.

What are BCAAs?

BCAA stands for branched-chain amino acids. These are three specific amino acids: leucine, isoleucine, and valine. These three are called essential because your body cannot produce them itself. Therefore, you must obtain them through your diet.

What makes BCAAs special is that they are processed differently from other amino acids. While most amino acids first go through the liver, BCAAs are broken down directly in the muscles. This sounds impressive, and the supplement industry has eagerly capitalised on it. BCAAs make up around forty percent of the essential amino acids in your body and fourteen to eighteen percent of the amino acids in your muscles.

Leucine plays a leading role in this. This amino acid activates an important signalling pathway in your muscles that is responsible for muscle growth. This is also the reason why most BCAA supplements contain a ratio of 2:1:1 leucine, isoleucine and valine.

The hard truth: what does science say?

Let's be honest. The scientific evidence for BCAA supplements is disappointingly weak. A large-scale study from 2022 (https://pubmed.ncbi.nlm.nih.gov/36235655/analysed twenty-four studies on BCAAs in athletes. The conclusion? The benefits for performance and muscle building were negligible.

What is more painful: research shows (https://pmc.ncbi.nlm.nih.gov/articles/PMC5568273/BCAA supplements alone do not promote muscle growth. Why not? Simple: to build new muscle tissue, you need all nine essential amino acids, not just three. If you only take BCAAs, your body won't have enough building blocks to actually create muscle mass.

A study by King's College Londonhttps://www.kcl.ac.uk/news/bcaa-supplements-not-most-effective-type-of-supplements-for-stimulating-muscle-growth) confirms this. Supplements with all nine essential amino acids provide a twice as strong stimulation of muscle building as BCAA supplements. In other words, if you're going to spend money on supplements, complete protein preparations are more effective.

There is one area where BCAAs do show some promise. Studies in strength athleteshttps://pmc.ncbi.nlm.nih.gov/articles/PMC6212987/), show that BCAAs can reduce muscle pain after training. A meta-analysis from 2024 (https://sportsmedicine-open.springeropen.com/articles/10.1186/s40798-024-00686-9confirms this, especially when people use BCAAs for longer periods. Research from 2025https://journals.sagepub.com/doi/10.1177/15579883251332731demonstrates that BCAAs are more effective for reducing muscle soreness immediately after training than before training. However, be aware: this refers to reduced muscle soreness, not automatically better performance or faster recovery. Despite BCAAs reducing muscle soreness, researchers did not always observe a simultaneous recovery of muscle strength.

Interesting is a recent study from April 2025 (https://www.mdpi.com/2072-6643/17/7/1290) who did find some effects in endurance athletes: BCAAs led to a more efficient fat-burning process and reduced fatigue after training. However, the question remains whether these effects also occur in people who simply eat enough protein.

You're already eating them: BCAAs in your daily diet

Here comes the main point. If you just eat enough protein, you'll automatically get enough BCAAs. No supplements needed.

Meat, fish, eggs, dairy, legumes, nuts: they are all packed with them. A hundred grams of chicken breast already contains more than six grams of BCAAs. A cup of Greek yogurt provides about five grams. Even plant-based sources like lentils and quinoa contain substantial amounts.

For the average adult, approximately 68 milligrams of BCAAs per kilogram of body weight per day are recommended. This increases to about 144 milligrams per kilogram during intensive training. This sounds like a lot, but consider: if you consume 1.5 to 2 grams of protein per kilogram of body weight, which is recommended for athletes, you will be well above this.

The interesting thing is that BCAA intake strongly correlates with animal protein consumption, but only weakly with plant-based protein. However, you will get more than enough through a varied diet with both animal and plant-based proteins.

My opinion as a sports nutrition coach

You know me by now. I'm hesitant about supplements, especially when the scientific evidence is shaky. And that's certainly the case with BCAAs. The Australian Institute of Sport places BCAAs in category C: supplements without sufficient scientific substantiation in athletes or with conflicting research results.

Most recreational and amateur athletes get more than enough BCAAs from their normal diet. If you're getting your daily protein intake consistently, such as from meat, fish, eggs, dairy, or plant-based alternatives, then you don't need extra BCAAs. It's simply doubling up, and especially an expensive way to get something you already have.

Furthermore, even if BCAAs had any effect, complete protein sources are still more effective. Why? Because they contain all nine essential amino acids that your body needs for muscle growth. A scoop of whey protein or an extra portion of cottage cheese after your workout gives your body more of what it's asking for than a pot of BCAA powder.

The last word

BCAAs are not a miracle cure. The marketing suggests you can't do without them, but science tells a different story. For the recreational athlete who simply wants to exercise healthily and stay fit, they are redundant. For the amateur athlete who trains seriously? Even then, you get enough through normal nutrition.

There are better things to focus on: good nutrition, sufficient sleep, a good training schedule. These are the foundations. Only when these are in order can you potentially look at supplements. And even then, there are better options than BCAAs.

My advice? Invest your money in quality food rather than supplements with questionable benefits. A piece of salmon, a good steak, free-range eggs, or quality dairy will give you much more for your money. Plus all the other nutrients your body needs.

Because let's be honest: the gym industry runs on selling supplements. But your body runs on good nutrition. And that's fundamentally different.