BCAAs and Testosterone: How Necessary are They?

By Ali Kuoppala | Last reviewed Tue 25 September 2018

Medical Review by Gerardo Sison, PharmD

BCAAs (Branched-chain amino acids) are leucine, isoleucine, and valine, and the name is simply derived from their branch chained looking chemical structure.

Those three amino’s all belong to the category of essential amino acids for human survival. And research shows that they’re the main amino acids behind muscle protein synthesis.

Sure there are roughly about 20 amino acids that the muscle consist of, but BCAAs (leucine, isoleucine, and valine) comprise a third of the amino acids in muscle tissue.

Branched-chain amino acids also differ from the other amino’s because they’re not metabolized in the liver (like rest of them are), instead, BCAAs are metabolized directly in the muscle tissue. Meaning that when you ingest BCAAs your muscles can almost instantly use them as energy and to stimulate muscle protein synthesis.

Because of the fact that they’re the main amino acids behind muscle protein synthesis, and can be directly used by the muscle tissue as energy, supplementation with BCAAs pre – post – and after training has became a norm in the bodybuilding world. Now there’s a ton of different BCAA supplements on the market, all claiming to be better than the other.

However, the greedy marketers of the supplement companies often leave out the most crucial fact…

…If you’re not training in a fasted state, BCAA supplementation is a complete waste of your time and money, because if you eat protein, you’re also consuming a ton of BCAAs.

Whey protein contains 25% BCAAs, animal protein contains roughly 18% BCAAs, egg white protein has around 18% BCAAs, the protein in cottage cheese has roughly 13% BCAAs, bean and pea protein has around 4%, and the protein in nuts only contains about 2% of BCAAs.

In other words: By eating 100 grams of chicken breast meat, you’d be consuming roughly 1,5-2 times the amount of BCAAs that you’d get in a “recommended dosage” of a BCAA supplement.

So does this mean that BCAAs are a complete waste of money and time?

Answer: If you’re not doing the fasted training then you have no reason whatsoever to consume BCAAs, you get plenty of them via foods and they’re present in your body during workouts.

However, if you’re doing fasted training in part with intermittent fasting (which is an incredibly awesome way to stimulate anabolic hormones and torch body fat), then BCAA supplementation is essential and extremely important.

That’s because if you’re in a fasted state, you may not have those BCAAs available in your body during workouts, which would lead to slow gains and even to some muscle breakdown during exercise (not a surprise as we’re talking about the main amino’s behind protein synthesis).

To have those amino acids in your body, you would need to consume some protein (whey, chicken, beef, fish, etc) before the workout. However, this would also break the fast and cut you out of those massive fat melting and hormone stimulating benefits.

And that’s exactly where BCAA supplementation steps in…

By consuming BCAAs via instantized powder or tablet form, you can get plenty of those essential muscle building amino acids (leucine, isoleucine, and valine) into your muscle tissue without breaking the fast as they’re so low in calories. This suppresses the catabolic effects of fasted training.

That’s the only reason why I use and recommend BCAAs in a supplemental form. It’s great for people who do intermittent fasting and workout in a fasted state, simply because you can get the protein directly into the muscle tissue without breaking the fast.

Other than that a person who doesn’t follow an eating pattern like intermittent fasting – or doesn’t practice fasted training – has no use to BCAA supplementation.

BCAAs and Testosterone

bcaa how to use and what it doesNone of the articles in this blog would be complete if I wouldn’t talk about testosterone.

And since we’re discussing BCAAs today, here’s the latest research about the effects of BCAAs on male testosterone levels:

The evidence clearly shows that BCAA supplementation pre – during – and post-exercise seems to significantly increase testosterone levels, growth hormone levels, and muscle protein synthesis (study, study, study, study, study, study).

BUT this still doesn’t mean that you would need to supplement with BCAAs if you’re not doing any sort of fasted training. You can simply sip some whey protein powder during the workouts, or eat a bit more chicken – as I said above – protein packed foods are filled with BCAAs already.

So how much BCAAs should you consume when working out in a fasted state?

Answer: I use 5-7 grams pre-workout, 5-7 grams during workouts, and 5-7 grams after workouts when I’m training in a fasted state. An hour or two after I’m done with my training I start eating.

Go above that recommendation and you’re likely to break the fast and lose the enhanced fat burning and anabolic hormone stimulating effects that come with fasted training.

Is there a brand of BCAA you recommend?

Answer: I personally use and recommend this unflavored BCAA supplement from Optimum Nutrition, simply because I’m not a big fan of sweeteners, preservatives, fillers and other junk chemicals.

With that being said, leucine tastes pretty damn horrible, to be honest. And most people seem to have huge problems consuming unflavored BCAAs because of the incredibly nasty taste.

But if you’re not a bitch about it, you should buy the stuff unflavored, and just gulp it down like a man.


So there you go, a simplified guide on BCAAs and how to use them properly, along with the latest research on what the amino’s do to your hormones.

Here’s a concentrated form of the above:

If you workout in a fasted state, use 5-10 grams of BCAA pre, 5-10 grams during, and 5-10 grams post workouts. If you don’t workout in a fasted state, don’t use BCAA supplements.

Ali Kuoppala

Ali Kuoppala is the founder of Anabolic Men. He has authored and co-authored multiple men's health books and focuses on uncovering the methods of optimizing hormonal health. To date, his articles on various websites have been read more than 15-million times. To read more about Ali, visit his Medium article.