Why Derms Are All Obsessed With Protein Intake (And How It Can Help Aging Skin)

Protein has always been a mainstay in the well-being zeitgeist. From counting macros to Keto diets, discussing how much protein our bodies need seems to be an ever-present constant in the wellness conversation.

It’s a worthy debate, of course, as protein consumption influences not only muscle health, but bone, joint, and metabolic health, plus brain, and immune function. So it makes sense that so many health professionals would be invested in the discussion—it’s one of the core ways we support our bodies, so it’s vital to get it right.

More recently, however, the topic of protein consumption has entered the beauty conversation. More and more experts I speak to have emphasized how crucial a protein-rich diet is for the skin, hair, and nails.

The rationale centers on the idea of regeneration. The skin, hair, and nails are made up of proteins, which are made up of amino acids. And those amino acids have to come from the diet: “You need to give your body the raw materials to regenerate,” says board-certified holistic nutritionist Jennifer Hanway.

Why protein matters in skin and hair care

Protein conversations typically revolve around muscle mass—but the ways in which protein is used in the body are vast and varied. “Protein plays a role in building bones, muscles, cartilage, skin, and virtually every body part and tissue,” says registered dietitian nutritionist Alex Larson, MS, RDN about the benefits of protein. 

The skin, hair, and the nails are actually made up of several proteins, including keratin, collagen, and elastin. Keratin, collagen, and elastin are made up of amino acids (they’re commonly called the building blocks of protein). Where does our body get these amino acids, which then become keratin, collagen, and elastin? Consuming protein, be that from a plant or animal source. 

“A sufficient amount of protein as part of a healthy diet is essential to support the body’s ability to synthesize proteins of all types, including those in the skin,” board-certified dermatologist Hadley King, M.D., told mbg about protein and the skin. 

Essentially: By fueling the body with an adequate amount of high-quality protein, it can use the protein’s amino acids to build keratin, collagen, and elastin. 

For example, hair growth is highly dependent on getting enough amino acids to make keratin, explains board-certified dermatologist Neera Nathan, M.D. 

“We know in medicine from observation of people who have inherited disorders of vitamin metabolism deficiency or severe malnutrition that hair growth absolutely depends on basic nutrients and overall internal health. No questions there. So crash diets, restrictive diets, or diets completely void of protein can cause hair loss,” she says.

“When your body goes into panic mode and is trying to conserve resources, your hair will be among the first to suffer because it’s not an essential function. Those resources are going to be routed elsewhere.One of the most important things you can do is get enough protein because it’s needed to make hair. Our hair is primarily keratin, which is protein. It’s that simple.” 

Aging concerns may also be tied back to lack of protein in the diet. 

“I have [someone in my life] who I’ve had some conversations with about her eating because I feel she’s not getting enough protein. She came to me the other day and said, ‘I’m getting a wrinkle here.’ I told her, you’re aging because you’re not getting enough of the collagen you need,” says board-certified integrative medicine physician Taz Bhatia, M.D.

While there isn’t a lot of human-focused research on the subject (just given the complexities of those studies and ethical implications), animal studies have shown that diets low on protein are linked to collagen decline as well as skin barrier damage.

One study found that following a protein-free diet for eight days caused a “dramatic decrease1 in both types I and III collagen” in rats. Another showed that protein-lacking diets triggered atopic dermatitis and skin barrier issues in upwards of 89% of rat subjects2.

Brittle, breakable nails have also been connected to protein concerns. “Nails are made of mainly hardened proteins,” says Amy Lin, the founder of sundays—a nail care salon focused on wellness. “When we’re low in protein, calcium, or other vitamins, that can sometimes show up on your fingernails”—be it as ridges, discoloration, or overall brittleness.

The surge of interest in protein in the beauty space 

Why are people interested in how protein influences their skin, hair, and nails? And why has it become such a strong talking point for beauty professionals as well? 

Well, that’s simply because these areas are the first to be affected. And since they’re external facing parts of the body, they’re highly visible. And the rest is simple: people react to what they see. 

“Since the body’s exterior is largely made of protein, the first signs of protein deficiency are often on the surface,” Michael Hirt, M.D., an internal medicine doctor who is also board-certified in nutrition, says about protein deficiency.

“Our emergency systems will break down non-essential tissues—like your skin—and repurpose those quality proteins to repair the heart or blood vessels or make certain life-sustaining hormones and blood proteins.”

Medical professionals, of course, have understood for some time that protein is a very important part of skin function. But now, the general public’s appetite for protein-related information has grown, specifically within the beauty industry. 

“The beauty world follows the wellness and fitness world in a lot of ways,” says Hanway. 

The influx of new aesthetic treatments, too, have helped spur this interest. The best innovations in in-office, non-invasive procedures are rooted in regenerative medicine—things like exosome therapy3, PRF (next generation PRP), Sofwave—work by encouraging the skin to heal itself and restore its own collagen and elastin.

“With these aesthetic treatments that are regulating your body’s natural collagen and elastin production, the body can’t do those things without the raw materials,” she says. “If you don’t have those building blocks of collagen in your skin, or you are just so stressed out and so depleted that anything new that you make is just going to break down again, you are wasting your money—and these things are not cheap.”

Finally, beauty supplements have exploded in popularity over the last several years. And many of them contain amino acids—be that from plant sources or collagen peptides in collagen supplements. “I think we’re at this point where people really do understand the connection between what you put into your body and how it looks on the outside,” says Hanway. 

How much protein do we actually need? 

The Recommended Dietary Allowance (RDA) of protein is 0.8 gram per kilogram of body weight4 per day. This is the minimum amount of protein a sedentary person needs to meet their nutritional requirements and avoid a nitrogen imbalance, so it’s conservative.

And the truth is that how much protein the body needs is highly individual. And historically, the protein conversation typically revolved around men—given that was whom the majority of the research was conducted on. However, more recent studies have shown how there’s a lot more nuance in women’s protein needs, especially during different phases of the cycle, pregnancy, or during menopause. 

This is to say that the answer to how much protein you need to consume will vary person-to-person, as well as due to what’s happening in your life. 

But a good rule of thumb is this: most active women will want to consume 1.2 to 2.0 grams of protein per kilogram of body weight. Most of the experts we regularly work with suggest aiming for a goal of around 100 grams of protein per day. “For most women, 100 to 120 grams is a really good starting point,” Hanway says. 

Where you are getting your protein matters, too. Look for sustainable, whole food sources of protein, like grass-fed beef, wild-caught fish, or organic proteins when you can, recommends Hanway.

Animal protein tends to be higher in the amino acids that our bodies need to regenerate than plant proteins. That’s not to say you can’t meet your protein needs as a vegan or vegetarian; it just takes more effort and planning.

And of course, it’s only one part of the broader picture. Protein should never come at the expense of fruits, vegetables, and healthy fats. “There are other factors, as well. It’s fantastic if we’re having our protein, but we also need so many vitamin, mineral, and antioxidant co-factors to help with the collagen and elastin production,” she says. 

The takeaway 

The skin, hair, and nails are made up of a variety of proteins—and to produce them, we need their building blocks: Amino acids, via protein consumption. The surge of interest in the beauty space largely has to do with the increased interest in regenerative medicine, and how we can best support our body so it can adequately produce these structural proteins. Want help meeting your protein goals? Here are expert-approved tips on how to consume more protein daily.