(Back to Basics)

If You're Looking For Longer, Stronger Hair, This Is The Ingredient To Try

Amino acids are the hair care trend to jump on ASAP.

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With new products, brands, and categories popping up every day, beauty can be a bit overwhelming. Back to Basics is our rudimentary beauty series that serves as your crash course on the science behind some of the best formulations in the game.

There are certain well-known hair care ingredients that many immediately gravitate towards. You've probably heard of them: shea butter, glycerin, ceramides, the list goes on. Less notable, however, are amino acids for hair, which are actually proving extremely beneficial for increased moisture, strength, and dandruff relief. To find out the true ins-and-outs of this buzzy ingredient, TZR tapped two hair experts who explained just how critical amino acids are for a lush, healthy head of hair.

What Are Amino Acids?

"All hair is made of the same keratin and amino acids," Bridgette Hill, certified trichologist says. She says that structurally, amino acids are the building blocks of polypeptides and proteins and are essential for physical development, necessary for other functions of the body such as hair and nail growth. "Keratin, the protein that makes up 95% of hair is made up of over 18 types of amino acids," she says. "When discussing hair care and scalp care it is important to make the direct connection to the body as well. There is evidence that hair fibers and scalp receive benefits from hair care products formulated with amino acids." She says that to truly impact the health of scalp and hair, the body must have the necessary essential and non-essential amino acids. This can be achieved through a diet that provides all 20 amino acids or supported through a dietary supplement.

The state of your hair, according to Hill, determines how beneficial amino acids will be to the hair. "Some hair needs more help with strength and moisture than others — for example, highly colored or processed hair, and curly and coily hair types," she says. "When the hair fiber is damaged or has a cuticle that is naturally more open than straight — glassy hair — it is weakened and has a hard time holding on to moisture, like a bucket with holes in it. By using hair products that contain protein and amino acids in combination with [ingredients for] moisture, hair strength, and hydration can be improved."


According to Sophy Phillips, resident hair technician for Monday Haircare, the benefit of protein and amino acids in hair care is that protein adds strength to the strands and allows the hair to hold on to moisture. Hill agrees. "Amino acids bind to the cuticle filling in the gaps and aid in creating a shiny look and silky feel to the hair," Hill says. "In scalp care, certain amino acids aid in managing both pityriasis capitis, [also known as] dry dandruff, and pityriasis steatoides — also known as greasy dandruff."

Best Kinds Of Amino Acids

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According to Hill, the best amino acids essential for hair growth have been identified as cysteine, which provides sulfur to hair cells, improving strength, elasticity, and hair texture; arginine, which supports blood circulation around the hair follicle; lysine, a restorative amino acid that supports collagen production; and methionine, which aids in making pre-collagen, which becomes collagen.

"The medical and science community have identified cysteine as the most important amino acid for hair growth," Hill says. "Sulfur amino acids such as cysteine and methionine help with managing dandruff by reducing skin cell build up as well as offer antimicrobial properties." Depending on the hair product, the brand may specify exactly what type of amino acid is included in the formula. However, in most cases, simply "amino acids" will be listed.

Amino Acids For Natural Hair

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"Hair care products formulated with amino acids have a positive impact on all hair types and textures," Hill says. "Curly to coily hair textures benefit from silk amino acids, like sericin, which is highly moisturizing." She also includes that equally as important is a diet filled with amino acids as well, to truly achieve optimum scalp and hair health from the inside out. Sulfur amino acids such as cysteine and methionine help with managing dandruff by reducing skin cell build-up as well as offer antimicrobial properties.

And even better news, there are few risks involved with using products with amino acids. "The only negatives would be allergic reactions or ingredient sensitives," Hill says. "I advise everyone to be mindful of this when incorporating any new products into a scalp care and hair care regimen."

We only include products that have been independently selected by TZR’s editorial team. However, we may receive a portion of sales if you purchase a product through a link in this article.