Do You Need To Take Amino Acids?
From recovery to muscle growth, here’s what the science says about amino acids—and whether adding them makes sense for your routine.
Shutterstock/Paul Biryukov
Walk into any gym and you’ll see shaker bottles filled with powders promising strength, recovery, or both. One of the most talked-about categories right now? Amino acids. They’re more than just a trendy supplement. They’re the molecules that make muscle growth possible. And the research is clear: the right blend, especially EAAs with leucine, can give your training a measurable edge.
Aminos 101
Amino acids are the building blocks of protein. Your body uses them to repair and rebuild muscle tissue after exercise. Of the 20 amino acids, nine are classified as essential amino acids (EAAs) because the body cannot make them on its own. They must come from food or supplementation.
EAAs vs. BCAAs
Within the nine EAAs is a subgroup known as branched-chain amino acids (BCAAs), which include leucine, isoleucine, and valine. BCAAs have long been popular in sports nutrition because they help reduce muscle breakdown and can signal the start of muscle repair. Here’s why they matter:
• Leucine is considered the most important of the three. It acts like a switch, turning on a pathway in the body called mTOR that signals it’s time to build muscle.
• Isoleucine and valine help with energy production during exercise and reduce muscle breakdown.
So when you see “BCAA” supplements, you’re getting just those three amino acids. They can be useful, but they don’t provide the other six essential amino acids your muscles also need to actually rebuild and grow.
What the Research Says
Several studies highlight the benefits of supplementing with EAAs, especially when leucine is included in higher amounts. These include:
• Reduced soreness: A meta-analysis in Applied Physiology, Nutrition, and Metabolism found that amino acid supplementation reduced muscle soreness and muscle damage markers after exercise.
• Muscle growth: A review in Frontiers in Physiology explained that while leucine activates muscle protein synthesis, all nine EAAs are required to sustain it and build new muscle tissue.
• EAAs are superior: A study in Nutrition & Metabolism concluded that leucine-enriched EAA formulas were more effective than BCAAs alone at improving net muscle protein balance. Think of BCAAs as the spark—they signal your body to begin recovery. EAAs with leucine, on the other hand, are the full toolkit: they provide the spark and the raw materials your muscles need to repair and grow stronger. That combination is what makes them more effective for strength and recovery than BCAAs alone.
So, Do You Need to Supplement EAAs?
If you’re consistently eating enough high-quality protein, you may already be covering your amino needs. But if you train hard and often, struggle to hit your protein targets, or want faster recovery and less soreness, then EAAs with leucine can be a smart, science-backed addition.
The Pretty Local POV
Supplements aren’t a shortcut; you still need a balanced diet, rest, and smart training. But EAAs with leucine stand out as a recovery ally, helping reduce soreness, improve muscle repair, and maximize the results of the work you’re already putting in.
I’ve been using Kion Aminos, which are formulated with all nine EAAs plus leucine, and I’ve noticed a real difference in how quickly I recover between strength sessions. You can check them out here and get up to a 20% discount on your purchases.
Here’s my progress from January, when I added creatine to my diet. I added Aminos on August 1st. Photo taken at the end of September.
