In short: amino acids are the "building blocks" that make up proteins, but not all amino acids have the same metabolic effect. Essential amino acids (EAA) are the main drivers of muscle protein synthesis stimulation. Recent research confirms that adding EAA to a whey protein can further boost muscle growth compared to whey alone, while not all plant protein sources offer the same availability of EAA in the blood. Raw material quality and production process remain decisive for the safety and effectiveness of the final product.
Today we'll find out together what the essential difference is between amino acids and proteins, and why you should never confuse the two.
We'll also clarify whether, after a workout, it's better to take amino acid-based supplements or protein powder, and finally we'll look at the best amino acid supplements on the market.
Let's dive right into this journey to discover essential amino acids: in our guide "Do muscles grow more with animal or plant proteins?" we analyzed the main factors that support protein synthesis and found that essential amino acids are the primary drivers. In fact, there's a strong correlation between the dose of essential amino acids ingested and the stimulation of protein synthesis.
What's the difference between amino acids and proteins?
Amino acids are defined as the "building blocks" that make up proteins: so we can say that proteins are a collection of amino acids. This doesn't mean, however, that ingesting amino acids or proteins indiscriminately gives the same result: each type of amino acid can trigger a different metabolic effect.
To explain it better: a cluster of amino acids forms a peptide, and a cluster of multiple peptides forms a protein.
After a workout, is it better to supplement with amino acids or protein powder to build muscle?
Answering this question wasn't easy, because after years of debate over whether whey protein was the best post-workout protein, a study from the International Society of Sports Nutrition showed that the ideal approach would be to use a whey protein with an additional supply of essential amino acids: the effect achieved in that study was 3 to 6 times greater muscle growth compared to whey protein alone, attributed to the rapid rise in essential amino acid concentration in the blood.
More recent research adds important nuance to this picture. A 2025 systematic review published in the Journal of Cachexia, Sarcopenia and Muscle confirmed that combining leucine-enriched whey (the essential amino acid most involved in activating the mTOR pathway) with resistance training produces significant benefits for muscle mass, strength, and physical performance, particularly in older adults with sarcopenia (DOI: 10.1002/jcsm.70060).
A 2025 study published in The Journal of Nutrition, conducted on healthy young women, instead showed that a single 20 g dose of protein (whey or canola protein) after exercise did not further increase the rate of muscle protein synthesis compared to exercise alone in the first hours of recovery, although it did confirm significantly higher plasma availability of essential amino acids with whey compared to the plant source (DOI: 10.1016/j.tjnut.2025.10.018). This confirms that not all protein sources are equivalent in their ability to make essential amino acids available in the blood, a key factor for protein synthesis.
That's exactly why, together with our experts, we developed Ultra Amino Whey, a combination of whey protein and the right amount of essential amino acids.
What are amino acids used for at the gym?
Amino acids are the fundamental building blocks of proteins and play a key role in muscle protein synthesis. When you train intensely, your muscles undergo stress and develop micro-tears: amino acids provide the nutrients needed to repair and rebuild damaged muscle, promoting muscle growth and recovery.
Adding amino acids to your diet can help you maximize your efforts at the gym. Ultra Amino Whey is an amino acid and protein supplement, also ideal for those who want to reduce or eliminate meat from their diet while maintaining the same protein intake.
The best amino acids and proteins on the market
Among the best amino acid producers on the market, two large companies stand out: Ajinomoto and Kyowa, both Japanese, with over a century of experience in plant-based fermentation. These two companies have patented their production processes to guarantee product quality and the absence of impurities, chemical additives, or synthetic substances.
For the production of our products, we rely only on them because we want to always offer you the best.
Not everyone follows the same standard: a study published by the American Food Journal of Food Sciences in 2013 found that some low-cost amino acid supplements, available on some online marketplaces, were derived from animal by-products not always clearly disclosed on the label. Determining where the ingredients come from therefore remains important.
Unfortunately, not all amino acids and proteins in general are equal: the type of production and the raw materials are the number one difference between a quality product and a low-cost one. A common, inexpensive method is strong acid extraction from animal by-products: over several hours, raw ingredients are exposed to high heat and strong acids, causing hydrolysis. The result is hydrolyzed amino acids that must then be filtered, dried, and refined. Although this method is cheaper, it can result in a product with more contaminants and allergens.
BIOAMIN is a dietary supplement based on essential and semi-essential amino acids produced through natural plant-based fermentation ("Animal Free"), enriched with a natural phytocomplex rich in B vitamins, folic acid, polyphenols and polysaccharides, cold-extracted from red fruit and vegetables, with an innovative stoichiometric amino acid ratio to improve absorption and bioavailability.
Our advice: choose fermented amino acids
Although they cost more, essential amino acids derived from plant-based fermentation are generally considered safer (because they're certified against pollutants and impurities) and offer several advantages:
- Better antioxidant properties, beneficial for the immune system and bone health
- Better bioavailability, meaning higher absorption rates
- Positive effects on the gut microbiota and the natural barrier between blood and the gastrointestinal tract
- Production free of synthetic chemicals
- Greater availability of amino acids even in powder formulations
- Formation of new phytonutrients: a study in the International Journal of Food Science and Nutrition found that fermentation of fenugreek leaves can generate vitamin B12
Frequently asked questions
Q: What's the difference between amino acids and proteins?
A: Amino acids are the basic units that, joined in chains (peptides), form proteins. Not all amino acids have the same effect: essential amino acids (EAA) are the primary drivers of muscle protein synthesis stimulation.
Q: Is it better to take amino acids or protein powder after a workout?
A: According to research, combining whey with additional essential amino acids can boost the anabolic response compared to whey alone, thanks to the rapid rise in EAA concentration in the blood.
Q: Do plant proteins work like whey for muscle growth?
A: A 2025 study showed lower plasma availability of essential amino acids with plant proteins (canola) compared to whey, although this doesn't always translate into a measurable difference in short-term protein synthesis. Protein quality and source remain relevant nonetheless.
Q: Why choose amino acids from plant-based fermentation?
A: For greater purity, the absence of synthetic chemicals, and better bioavailability compared to some low-cost extraction processes from animal by-products.
Q: Are essential amino acids also useful for older adults?
A: Yes: a 2025 review confirmed that leucine-enriched whey combined with resistance training helps counter sarcopenia, improving muscle mass, strength, and physical performance in older adults.
Sources:
Park Y. et al. (2020) J Int Soc Sports Nutr 17:9. DOI: 10.1186/s12970-020-0340-5
Ijaz A. et al. (2025) — Enhancing Muscle Quality: Exploring Leucine and Whey Protein in Sarcopenic Individuals. J Cachexia Sarcopenia Muscle 16(5):e70060. DOI: 10.1002/jcsm.70060 (PubMed)
Boot N. et al. (2025) — Ingestion of 20 g Whey or Canola Protein Does Not Further Increase Muscle Protein Synthesis Rates During Recovery From Resistance Exercise in Healthy, Young Females. J Nutr 155(12):4123-4135. DOI: 10.1016/j.tjnut.2025.10.018 (PubMed)
