Amino Acids for Hair Growth
Surely amino acids aka protein have something to do with your hair loss. I mean, more protein is the solution to muscle growth and manliness in general, right? There isn’t much that a giant steak (and whiskey) can’t solve -- just ask Ron Swanson.
Jokes aside, you’re facing a threat to your attractiveness and youth. You feel it and science has confirmed it. You can pretend to shrug it off all you want, but losing your hair is scary. You’re not alone. One-fourth of American men have some hair loss by age 21 and two-thirds by age 35, according to the American Hair Loss Association. Still, we know you’d rather not be a part of this club.
The list of junk science and quackery surrounding hair loss solutions is long. Nutritional supplements, herbs, shampoos, and home remedies that promise fast hair growth are a dime a dozen, and you could waste a lot of time and money testing them all out.
So, where do amino acids and proteins fit in? We’re about to break down the science, but here are the main takeaways:
- Amino acids are present and crucial in nearly all of your tissues, including your hair.
- The chance that your thinning hair is caused by an amino acid or protein deficiency is very, very slim.
- The is no clear, convincing evidence that amino acid supplementation or topical solutions can improve hair growth in men.
- Few hair loss treatments on the market are actually backed by scientifically-sound research. Finasteride and minoxidil are among those few.
What Are Amino Acids?
Proteins are "the building blocks of life!" You’ve heard it before. We all have. Since like junior high biology class. But you may not know that amino acids are the building blocks of proteins -- they are organic compounds that make up the larger protein molecules.
"You can think of a protein as a string of beads, where each bead is an amino acid," explains Khan Academy. The links of the chain: peptide bonds. But, we’re getting too deep.
In all, there are 20 amino acids required by the body. Our bodies produce some naturally. Though they are important, they’re known as "nonessential" amino acids. The others, known as “essential” amino acids, we must get from our diet. Once your body breaks proteins down, the smaller essential and nonessential amino acids are absorbed and go to work doing what they do best.
So, what do they do?
Amino acids play a role in many bodily (and cellular) functions: acting as an energy source, breaking down food, transporting nutrients, removing waste produced by metabolism, repairing and growing body tissue, aiding in immune function, regulating hormones, regulating appetite, and on, and on. Bottomline: they’re vital. Without them, the human body and all of its proteins -- including our hair -- would be impossible.
When it comes to hair growth, amino acids are necessary, but that alone shouldn’t send you out for new supplements.
Amino Acids and Your Hair
"Unlike in the case of the skin, the presence and the role of naturally occurring free amino acids in hair shafts are not known yet," reads a 2007 study in the Journal of Cosmetic Science. Yes, as with most science, what we don’t know about amino acids and hair loss far outweighs what we do.
Like the rest of your body, your hair is loaded with amino acids. There, they’re found naturally in the form of keratin, the type of protein your hair is made of. But amino acids are also created as result of protein degradation caused by environmental damage, for example, not just present in keratin when the hair leaves your scalp. Also, there are several things that can change the chemical makeup of your hair, your hair follicles and your ability to grow hair. Aging, weather damage, chemical processing, genetics and nutritional deficiencies may impact amino acid concentration in the existing hair alone.
Because there are so many factors at play, the solution to hair loss isn’t as simple as, "the sun depletes arginine (an amino acid) in your hair, so take an arginine supplement!" Many websites and snake oil peddlers would love to convince you otherwise, however, as they’re selling solutions backed by oversimplified statements just like this. If only it were so simple.
As a matter of fact, research that definitively ties treatments to
There is concrete evidence that biotin, topical minoxidil, and finasteride can be effective, but when it comes to most nutritional supplements and cosmetic applications, that same clear evidence doesn’t exist.
The Research: Nutrition
Cysteine, an amino acid, makes up about one-fourth of keratin -- the key protein that makes up every strand of what’s left of your hair. It is also useful in protecting your hair and hair root from oxidative stress. A few small studies have linked cysteine supplementation to positive results:
- In a 1998 study, volunteers took 4 pills each day containing cysteine for 50 weeks. They saw a 50% increase in hair growth. However, the entire study only included 48 volunteers, half of which were men. Further, just 12 people total took the supplement.
- Forty women took a supplement including cysteine for a period of 6 months and showed a "significant" change in hair growth compared to the placebo group. However, the supplement included other ingredients, making it difficult to credit the cysteine alone.
Lysine is another amino acid present in your hair, required for the production of collagen (a protein!), and present in hair roots. If you’ve done any amount of research on amino acids and hair loss, there’s a chance you’ve heard of lysine, largely because of this research:
- When paired with iron, there
isevidence women with pattern hair loss may experience a decrease in shedding with lysine supplementation. However, hair loss in women has historically been tied to anemia or iron deficiency, so it can’t be said that the lysine alone is helpful, nor can it be said that the same results would occur in men.
The Research: Topical Applications
Scientists, often funded by the cosmetic industry, have spent quite a bit of time and energy looking at the effects of proteins applied directly to the hair. Because chemical reactions, like those that happen in the sun or when you color your hair, can deplete proteins and amino acids in the hair, the research has largely focused on the effects of hair products on hair health and strength, not hair loss or growth.
For example, in 2005, a study in the Journal of the American Academy of Dermatology, said that 6 different amino acids can be lost during hair "weathering", but that some of these amino acids can be reintroduced to the hair. Cosmetic applications containing amino acids, the researchers said, “had a direct effect on the strength of the hair”.
But unless your hair loss is caused by damage from coloring, heat styling, the environment or other external factors, it’s unlikely this existing research applies to you.
In rare cases, hair thinning and loss can be caused by protein deficiency and malnutrition. In the modern Western world, it’s highly unlikely this is what’s behind your balding -- even if you’re on the trendy vegan train. Protein deficiency in the U.S. is "very rare" and is caused by not enough food, in general, not just a lack of animal-based protein. On the
As the scientists put it:
"While trials of amino acid and protein supplements have been published, they are formulated with a variety of nutrients, and therefore it is unclear what role, if any, is played by amino acid and protein supplementation in the absence of known deficiency."
This article was reviewed by Brendan Levy, MD