Do you need amino acid supplements?
Usually not, if you already eat enough protein. If you do buy aminos, pick EAAs over BCAAs. But 20 g of whey isolate already holds about 10 g of EAAs.
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Do you need amino acid supplements?
Usually not. Protein is made of amino acids, so eating enough protein gives you them.
In most cases, the British Dietetic Association says a healthy, balanced diet should provide enough protein. You just need to eat enough to fuel your training.
Adults need nine amino acids from food. These are the essential amino acids (EAAs). BCAAs are just three of them: leucine, valine and isoleucine.
Sources: British Nutrition Foundation; Wolfe 2017
Think of new muscle as a cake that needs nine ingredients. BCAAs bring three.
Protein researcher Robert Wolfe says the other six then have to come from muscle your body breaks down. So BCAAs on their own can only go so far.
Start by checking how much protein you eat. Our guide to how much protein per day has the sums.
EAAs vs BCAAs: which is better?
| BCAAs | EAAs | |
|---|---|---|
| What’s in it | 3 of the 9 essential amino acids | All 9 |
| After a workout | 5.6 g raised muscle building 22% more than a dummy drink over 4 hours, in 10 young trained men | The same team says all 9 may be needed for the biggest effect |
| Against whey | About half the rise seen with whey holding the same BCAAs | In older women, 3 g raised muscle building over a few hours about as much as 20 g of whey |
Sources: Jackman 2017; ISSN 2023
So if you buy one, pick EAAs. The BCAA trial was small, with 10 trained men, and measured muscle building for 4 hours.
One catch: Wolfe and other authors of the ISSN paper on EAAs hold patents or shares in EAA products. The paper is from the International Society of Sports Nutrition, a sports science group. Its muscle data mostly track hours, not months.
For muscle you can see, the ISSN points to weight training plus enough protein. See protein to build muscle.
Is a scoop of whey as good as aminos?
Often, yes. That scoop is an EAA supplement already. The ISSN says 20 g of whey isolate holds about 10 g of EAAs, inside the 15 g it calls reasonable.
Meat, fish, eggs and dairy carry all nine EAAs. Plant eaters get enough too from a mix of plant foods across the day, if they eat enough calories. See vegan protein sources.
Before you buy aminos: four steps
- 1
Work out your protein
0.75 g per kg a day for most adults. 1.4 to 2.0 g per kg for strength or endurance training.
- 2
Fill it with food
Meat, fish, eggs, dairy, or a mix of plant foods.
- 3
Short? Add a shake
20 g of whey isolate holds about 10 g of EAAs.
- 4
Still want aminos?
Pick EAAs, batch-tested, up to 15 g a dose.
Sources: British Nutrition Foundation; BDA; ISSN 2023; UKAD
Say you weigh 70 kg and lift weights. At 1.4 to 2.0 g per kg, that’s 98 to 140 g of protein a day. UK men eat about 85 g a day and women about 67 g, so a lifter may fall short.
Plant-based and training? See plant protein for strength training.
How much EAA per scoop?
At rest, the ISSN says muscle building starts at 1.5 to 3 g of EAAs. It seems to level off at about 15 to 18 g. It calls a dose of up to 15 g reasonable.
- Below 1.5 gBelow the doses shown to work at rest.
- 1.5 up to 15 gISSN: a reasonable dose.
- Above 15 gOver 15 g. The effect levels off by 15 to 18 g.
Source: ISSN 2023
Per meal, the ISSN suggests 20 to 40 g of protein, with 700 to 3,000 mg of leucine.
On the tub, look for grams of EAAs per scoop, not just total aminos.
What to check before you buy aminos
Five checks before you buy aminos
- Check the label lists all nine EAAs, not just leucine, valine and isoleucine.
- Look for grams of EAAs per scoop, and keep a dose at 15 g or less.
- Choose a batch-tested product, and check the batch number before use.
- If you compete in a tested sport, check the product on Informed Sport first.
- Don’t use it to cover a poor diet. Supplements won’t make up for poor food choices.
Why batch-tested? UK Anti-Doping, writing for athletes, says labels can be inaccurate, and products can pick up banned substances during manufacture.
Looking for the best brand? No trial we found compares them. The best tub is one that passes all five checks.
Also taking creatine? See creatine and protein together and supplements worth taking.
When to speak to a GP
Speak to a GP or your specialist team if:
- You have kidney disease. The ISSN says there’s not enough data on EAA safety when the kidneys don’t work well.
- You have PKU, an inherited condition where the body can’t break down phenylalanine. It’s one of the nine EAAs.
- You have maple syrup urine disease, a rare inherited condition where the body can’t break down BCAAs. The ISSN says EAAs could cause a bad reaction.
- You keep losing weight without changing your diet or exercise routine. The NHS says to see a GP.
Training for a tested sport? UK Anti-Doping says to ask a qualified medical professional whether you need a supplement at all.