EAAs vs BCAAs: Which Amino Acid Supplement Do You Actually Need?

EAAs vs BCAAs: Which Amino Acid Supplement Do You Actually Need?

EAAs contain all nine essential amino acids your muscles need to grow, while BCAAs contain only three, so EAAs are the better choice when you take an amino supplement at all.

What are amino acids, and why do they matter?

Protein is built from small units called amino acids. When you eat chicken, eggs, fish, dairy or lentils, your digestive system breaks that protein into amino acids, and your body reassembles them into muscle, enzymes, hormones and skin. Twenty amino acids take part in this process. Eleven can be made by the body. Nine cannot, so they must come from food. These nine are called the essential amino acids, or EAAs.

The nine essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. Muscle growth after training depends on having enough of all of them available at the same time. If one is missing, the building process slows down no matter how much of the others you supply.

What are BCAAs?

BCAAs are branched chain amino acids: leucine, isoleucine and valine. They are three of the nine essential amino acids, and they make up around a third of the essential amino acids in muscle protein. Leucine gets the most attention because it acts as a signal that switches on muscle protein building through a pathway called mTOR. Most BCAA products contain a 2:1:1 ratio of leucine, isoleucine and valine, though some use 4:1:1 or 8:1:1 to push the leucine amount higher.

The main problem with BCAAs on their own

For years, BCAA tubs were sold with promises of bigger muscles and faster recovery. The research tells a more careful story. A widely cited 2017 review by Professor Robert Wolfe in the Journal of the International Society of Sports Nutrition looked at the evidence and concluded that BCAAs alone cannot create a full muscle building response, because the six other essential amino acids are missing. Leucine can start the process, but the body needs the full set of raw materials to finish it.

Think of building a house. Leucine is the foreman who shouts "start building". If there are no bricks, wood or cement on site, the foreman can shout all day and nothing gets built. EAAs deliver the foreman and the materials together.

EAAs vs BCAAs: the direct comparison

  • Amino acids included. EAAs contain all nine essential amino acids. BCAAs contain three.
  • Muscle building signal. Both can trigger it, but only EAAs supply the complete set needed to finish the job.
  • Typical dose. EAA products usually suggest 10 to 15 grams. BCAA products usually suggest 5 to 10 grams.
  • Taste and mixing. Both are bitter without flavouring. Most products add sweeteners and flavours, so read the label if you avoid artificial sweeteners.
  • Cost. BCAAs are often cheaper per tub but give you less usable value per gram.
  • Best use. EAAs fit fasted training, low protein days and plant based diets. BCAAs have a small role when your overall protein is already high.

Do you need either one?

The honest answer for most people is: probably not, if you already eat enough protein. Studies show that people who reach a daily target of around 1.6 to 2.2 grams of protein per kilogram of body weight gain nothing extra from BCAAs, because a normal meal already contains plenty of leucine. A 30 gram serving of whey protein contains about 3 grams of leucine and all the other essential amino acids as well. Eggs, meat, fish, dairy and soy supply the full set too.

Before you buy an amino supplement, check your daily protein first. Use our guide to how much protein athletes really need and compare it with what you eat. If you are already close to your target, your money is better spent on food and sleep.

When EAAs can actually make sense

There are a few situations where an EAA supplement is a reasonable tool.

  1. Training fasted in the morning. If you cannot face a meal before an early session, 10 grams of EAAs can supply amino acids without a heavy stomach. Read more about fasted training pros and cons.
  2. Plant based diets with lower protein quality. Some plant proteins are lower in leucine or lysine. An EAA drink can fill the gap, though a mix of soy, pea and rice protein does the same job. See vegetarian and vegan athlete nutrition.
  3. Older adults. Muscle becomes less responsive to protein with age. Research suggests that older people may benefit from a slightly larger dose of leucine per meal.
  4. Long sessions between meals. During a very long training day, a sipped EAA drink can help you feel fresh until the next real meal.
  5. Lactose intolerance or dairy allergy. If whey does not suit you, EAAs are a dairy free source of amino acids.

What about recovery and soreness?

Some studies report that BCAAs slightly reduce muscle soreness after hard exercise. A meta analysis found small, inconsistent improvements, mostly in people who were not eating much protein to begin with. The effect is modest, not dramatic. Good sleep, enough total protein and sensible training volume do far more. If soreness is your main concern, our guide to managing delayed onset muscle soreness explains what works.

How to choose a good amino acid supplement

  1. Look for a transparent label. It should list each amino acid and the amount in grams, not hide them inside a "proprietary blend".
  2. Check the leucine content. A good EAA serving contains about 2.5 to 3 grams of leucine.
  3. Prefer third party testing. Seals from independent testing programmes reduce the risk of contamination or banned substances. Our guide on supplement quality and third party testing explains how.
  4. Avoid long lists of extras. Caffeine, herbal extracts and dozens of ingredients rarely add value and can cause side effects.
  5. Compare cost per serving. Divide the price by the number of servings, not the price by the tub size.

Safety and side effects

At normal doses of up to about 10 to 20 grams a day, amino acid supplements are well tolerated by healthy adults. Some people feel mild stomach upset when taking them on an empty stomach. Very high doses of single amino acids can compete with each other for absorption, which is another reason to choose a balanced EAA formula over a large amount of BCAAs alone. People with kidney or liver disease, pregnant or breastfeeding women, and anyone taking medication should speak with a doctor first.

A simple rule to remember

Build your base with food. Eat 1.6 to 2.2 grams of protein per kilogram of body weight, spread over three or four meals. If you still struggle to reach that, whey or plant protein is usually the easiest and cheapest fix. Use EAAs only for the special situations above. Skip BCAAs unless you already own a tub and want to finish it.

Frequently asked questions

Can I take BCAAs and EAAs together? There is no benefit in doing so. EAAs already contain BCAAs, so you would be paying twice for the same three amino acids.

Should I drink EAAs during my workout or after? Anywhere from 30 minutes before training to straight after works. Timing matters far less than your daily total.

Are EAAs better than whey protein? Not for most people. Whey is cheaper, tastes better, supplies all essential amino acids and gives more total protein. Read our comparison of whey, isolate and hydrolysate.

Will amino acids break my fast? Yes. Amino acids contain calories and trigger digestion, so they end a strict fast.

Can women take EAAs? Yes. Women have the same amino acid needs per kilogram of body weight, and the same dosing applies.

This article is general information and not medical advice. If you have a health condition or take medicine, speak with your doctor or a registered dietitian.

How FiTPLATE helps you use protein properly

Supplements are the last ten percent. FiTPLATE helps you win the first ninety.

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References

  • Wolfe RR. Branched chain amino acids and muscle protein synthesis in humans: myth or reality? Journal of the International Society of Sports Nutrition, 2017.
  • Jäger R et al. International Society of Sports Nutrition Position Stand: protein and exercise. Journal of the International Society of Sports Nutrition, 2017.
  • Schoenfeld BJ, Aragon AA. How much protein can the body use in a single meal for muscle building? Journal of the International Society of Sports Nutrition, 2018.