What amino acids really do for your skin, hair and muscles

If you’re trying to build muscle tone or simply sharpen up your health, chances are you’ve come across amino acids. They’re often touted for everything from boosting metabolism and supporting mood to improving skin collagen and muscle growth. But what are they really, and do we get enough from food alone—especially if you’re vegetarian or vegan? And when does it make sense to consider a supplement? To find out, we spoke to Jo Woodhurst, nutritionist and director of nutrition at Ancient+Brave.

Why amino acids matter

Why are amino acids such a big deal for the body? Think of them as the “building blocks” of protein and protein itself as the scaffolding that holds us together. From repairing tissues to powering metabolic processes, proteins are behind almost every function that keeps us alive. Amino acids make that possible. Picture them as the alphabet: on their own they create letters with distinct roles–from producing hormones to regulating neurotransmitters—but when strung together, they form words (peptides) and eventually whole sentences (proteins) that carry out the body’s most intricate tasks.

What are essential amino acids?

Our body needs 20 different amino acids to function. Of those 20, nine are considered “essential” amino acids (EAAs) because the body doesn’t make them naturally. Instead, these nine essential amino acids must be consumed via food.

Each amino acid has different functions. When combined into a protein, the role expands further. The human body is believed to contain between 10,000 and 50,000 different proteins—each with a unique purpose, including:

Structural materials such as muscles, skin, blood, ligaments, tendons, bones, collagen, and the walls of intestines and arteries.Enzymes that catalyse reactions essential for digestion, energy production and detoxification.

The nine essential amino acids are:

phenylalanineisoleucinehistidineleucinelysinemethioninethreoninetryptophanvalineWhat foods contain essential amino acids?

Essential amino acids cannot be produced by the body and must be consumed from the foods we eat. Luckily, plenty of foods that contain essential amino acids:

MeatFishPoultryEggsMilk and dairy productsSoybeans and derivatives (tofu, tempeh, miso)QuinoaBuckwheatHemp seedsPeanutsPeasWhat are the non-essential amino acids?

If nine of the 20 amino acids can’t be made by the body naturally, that means the remaining eleven amino acids can. As you may have guessed, these eleven are thus called “non-essential amino acids”—not because they aren’t necessary, but because the body needs them conditionally, like during times of stress, illness, or intense physical demands such as pregnancy.