The Full List: What Are the Names of the EAAs and BCAAs?

December 12, 2025 •

3 min read

Over 500 amino acids exist in nature, but only 20 are needed to create the proteins in the human body. Nine of these are essential amino acids (EAAs), meaning your body cannot produce them and you must get them from your diet. Among these EAAs is a special subgroup called branched-chain amino acids (BCAAs), comprising three specific names.

Quick Summary

The nine essential amino acids (EAAs) must be obtained through diet and include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Branched-chain amino acids (BCAAs) are a subset of EAAs, consisting of leucine, isoleucine, and valine.

Key Points

The Nine EAAs: The full list of Essential Amino Acids includes Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, and Valine.
The Three BCAAs: Branched-Chain Amino Acids are a subgroup of EAAs consisting of just three: Leucine, Isoleucine, and Valine.
Source vs. Synthesis: EAAs must be consumed through diet or supplements because the body cannot produce them, while BCAAs are part of that essential group and also require dietary intake.
Targeted vs. Complete: BCAAs are specifically targeted for muscle metabolism and recovery, whereas EAAs provide a complete profile for overall protein synthesis and health.
Maximum Synthesis: For maximum muscle protein synthesis, all nine EAAs are required, which means an EAA supplement is more comprehensive than a BCAA-only product.
Dietary Context: The need for supplementation depends on your diet; adequate intake of complete proteins can cover EAA needs, but athletes may still use BCAAs for workout-specific benefits.
Leucine's Role: Leucine is the most important BCAA for activating muscle protein synthesis, acting as the primary trigger for muscle growth.

What Are Essential Amino Acids (EAAs)?

Essential Amino Acids (EAAs) are the nine amino acids your body cannot produce itself, making dietary intake essential. They are fundamental for creating protein and are involved in crucial bodily functions like muscle development, tissue repair, and immune system support. Consuming a balanced diet with complete protein sources, such as meat or dairy, or combining plant-based foods, helps ensure you get all nine EAAs.

The nine Essential Amino Acids are:

Histidine: Involved in producing histamine, important for the immune response and other functions.
Isoleucine: A BCAA vital for muscle metabolism and hemoglobin production.
Leucine: A key BCAA known for activating muscle protein synthesis, aiding in muscle repair and growth.
Lysine: Essential for protein synthesis, calcium absorption, and hormone production.
Methionine: Important for metabolism, detoxification, and tissue growth.
Phenylalanine: Converted into neurotransmitters like dopamine and epinephrine; important for protein structure.
Threonine: A component of structural proteins like collagen and elastin.
Tryptophan: A precursor to serotonin, which influences mood, sleep, and appetite.
Valine: The third BCAA, supporting muscle growth, regeneration, and energy.

What Are Branched-Chain Amino Acids (BCAAs)?

Branched-Chain Amino Acids (BCAAs) are a specific subgroup of EAAs, characterized by their unique chemical structure. They differ from most amino acids by being primarily metabolized in the muscles rather than the liver. This makes them particularly popular for supporting exercise performance, reducing muscle fatigue, and aiding recovery.

The three Branched-Chain Amino Acids are:

Leucine: The most critical BCAA for initiating muscle protein synthesis.
Isoleucine: Supports muscle metabolism and immune function.
Valine: Works with leucine and isoleucine to stimulate muscle growth and repair.

EAA vs. BCAA: A Comprehensive Comparison

Understanding the differences between EAAs and BCAAs helps in choosing the right supplement. BCAAs are a subset of EAAs with a focused role. The table below highlights key distinctions.


Feature	BCAAs (Branched-Chain Amino Acids)	EAAs (Essential Amino Acids)
Composition	Consists of only three amino acids: Leucine, Isoleucine, and Valine.	Includes all nine essential amino acids: Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, and Valine.
Primary Function	Specifically targets muscle metabolism, protein synthesis activation (driven by Leucine), and reducing muscle fatigue.	Provides a more holistic approach, supplying all nine amino acids required for comprehensive protein synthesis, repair, and other vital bodily functions.
Completeness	Considered 'incomplete' for muscle building because they lack the six other essential amino acids needed for maximal protein synthesis.	Considered 'complete' for muscle building because they supply all necessary amino acids, making them more effective for sustained muscle growth.
Best for Athletes	Ideal for reducing muscle soreness and fatigue, particularly for high-intensity training. Can be effective for supplementing low-protein meals.	Optimal for maximizing muscle protein synthesis and overall recovery. A better choice if your diet is lacking in high-quality protein.
Absorption	Can be rapidly absorbed, making them ideal for consumption during a workout to prevent muscle breakdown.	When consumed as a complete supplement, absorption is comprehensive and supports broader needs.

When to Choose EAA over BCAA

While BCAAs target muscle recovery and performance, EAAs offer a complete profile necessary for overall health and maximum muscle building. Muscle protein synthesis requires all nine EAAs. If your diet is consistently high in complete proteins, BCAAs might offer an extra boost around workouts. However, for those with inconsistent or low-protein diets, an EAA supplement is more reliable for meeting all essential amino acid needs.

The Role of Amino Acids in Health and Performance

Amino acids are vital for nearly all physiological processes, forming proteins, enzymes, and hormones. The full spectrum of EAAs is critical for functions ranging from mood regulation to immune support. Optimizing amino acid intake through diet and/or supplementation can enhance athletic performance, speed recovery, and improve overall health.

Conclusion

To summarize, EAAs include all nine essential amino acids that the body cannot make, while BCAAs are a subset of three: leucine, isoleucine, and valine. BCAAs offer targeted benefits for muscle recovery, but all nine EAAs are necessary for maximum muscle protein synthesis and overall health. The best choice of supplement depends on your diet and goals; EAAs are better for comprehensive support if your diet is insufficient in complete protein, while BCAAs can provide a strategic boost for those already meeting their protein needs.

For further reading on the complex metabolic functions of these compounds, refer to the detailed review published in Nutrition & Metabolism.

Frequently Asked Questions

EAAs include all nine essential amino acids that the body cannot produce. BCAAs are a subgroup of EAAs, consisting of only three: leucine, isoleucine, and valine.

Leucine is considered the most important amino acid for muscle growth because it is the primary activator of the mTOR pathway, which initiates muscle protein synthesis.

No, BCAAs alone do not provide all the amino acids needed for complete muscle repair and growth. While they trigger protein synthesis, all nine EAAs are necessary to maximize the process.

If you want a more complete supplement for muscle growth and overall health, especially if your diet lacks protein, an EAA supplement is superior. BCAAs are a good choice if you already consume a high-protein diet and want to target muscle recovery around workouts.

Animal-based protein sources like meat, fish, eggs, and dairy products are considered complete proteins, containing all nine EAAs, including the BCAAs. Plant-based sources include soy and quinoa.

Amino acid supplements are generally safe, but excessive consumption can lead to side effects such as gastrointestinal distress. It's recommended to follow dosage instructions and consult a healthcare professional.

For exercise, amino acid supplements are often taken before, during, or after a workout. Pre-workout intake can help reduce fatigue, while post-workout consumption aids recovery.