When it comes to beauty treatments that promise to help us achieve our most radiant selves, skin, hair, and nails are marketed as the almighty trio. We are bombarded with messages telling us to take this specific supplement to make our hair, skin, and nails grow luscious and long; to eat these particular foods to support the health of the trio; or to do this certain type of exercise to achieve vibrant, glowing looks and locks.

But are skin, hair, and nails really the trifecta of beauty and health, or is this just a convenient marketing ploy for the beauty industry?

Beyond concerns for our outer appearance, many ob-gyns—the doctors on the frontline of women’s health—report that patients who come in concerned about one of these areas of the body often have interrelated concerns about the others. And for good reason. 

The way the beauty industry groups skin, hair, and nail concerns together may be a bit of a gimmick—a single supplement will never be the holy grail of beauty perfection for all—but these three parts do have a profound biological connection. So, focusing on the health of one may just provide a boost to all.

The Root of the Issue

While your skin, hair, and nails may seem wildly different in many ways, they are actually components of a single organ: the integumentary system. Thanks to skin—which spans a whopping 22 square feet—this is the largest organ system in the body.

But the common root of these beauty powerhouses goes even deeper. Dermatologist Dr. Sandy Skotnicki says the reason these three areas of the body are frequently linked together is because they are all part of the ectoderm, or a group of cells that develop during an embryo’s third week. “They all come from the same stem cell,” Skotnicki says. “Hair, nails, and skin are all connected.”

In addition to their origins, hair, nails, and the outer part of our skin are also all made up of a building block called keratin. This protein serves a protective function in each of these areas, helping to support a strong skin barrier, keeping your strands of hair supple and smooth, and reinforcing your nails to prevent breakage. “Essentially, they're all very similar,” Skotniki says.

The Role of Hormones

Beyond their structural similarities, the members of the integumentary system are also affected by hormones in similar, but specific ways. Many hormonal imbalances often appear early on as external symptoms. For this reason, it’s not uncommon to find that if a problem develops in one area—like brittle hair—you might also experience issues in the others.

As Dr. Gabrielle Francis says, “Your skin and your beauty are a reflection of your health on the inside.”

Take thyroid issues, for example. If your body produces too much thyroid hormone, like in the condition hyperthyroidism, you might experience skin redness and rashes, as well as thinning skin. But the overproduction of TSH also causes hair thinning because the excess hormone attacks hair follicles.

The most common hormonal cause of skin, hair, and nail issues occurs during menopause when lower estrogen levels give way to the increased production of androgens like testosterone that can weaken hair follicles leading to shedding, cause skin aging including thinning skin and wrinkles, and produce nails that are dry and brittle. 

“These three are certainly related and can be treated as such when symptoms are mild, such as the slow-growth of nails or hair and the dryness of hair, skin and nails,” Abdullah says. But it’s important to remember that there’s a difference between a hormonal problem that is causing skin, hair, and nail symptoms and the day-to-day work of keeping the trio healthy and strong.

How to Boost Your Skin, Hair, and Nail Health

The product frequently touted as “the answer” to better skin, hair and nails is collagen. According to Skotnicki, there is some concrete evidence that taking powdered collagen supplements might make a difference. She points to eleven studies involving 805 patients given collagen and says that the results included an increase in skin elasticity, moisture, and density, as well as a reduction in the breakdown of collagen. These studies show that there is evidence that collagen “can help with the ectoderm, right to the skin, hair, and nails,” Skotnicki says.

Not all supplements are created equal, especially in an industry that offers an endless number of choices with zero FDA regulation. If you are interested in taking a supplement that targets this trifecta, Abdullah says there are a few ingredients you should look for that will increase your chances of seeing results. 

• Biotin: Biotin is a building block for keratin and contributes to longer, stronger, shinier hair and nails, as well as better skin elasticity. In supplement form, Skotnicki says the evidence shows biotin predominantly aids the growth and appearance of nails and hair, with less evidence to suggest that it can help skin health.

• Hyaluronic acid: While most people know hyaluronic acid as a powerful topical skincare ingredient, it can also be found in supplements. In this form, it can help build more moisture into the skin and hair, which can lead to a plump, dewy face and less brittle locks. 

• Vitamins: Vitamins have a whole host of health benefits, but vitamins B and D, in particular, can help boost the look and feel of your skin, hair and nails.

Overall, Skotnicki says that any supplement you take for one of the three areas will potentially have some benefit for the others. As long as the supplement is pure (it’s always important to do your brand research before starting a new supplement), it doesn’t hurt to give it a try.

So, Is the Beauty Trifecta Accurate?

The short answer is yes. But, as in all health-related issues, the longer answer is a bit more complicated.

Skotnicki says that while she does see many products out there that claim to treat skin, hair, and nails together, she and her colleagues tend to focus more on the individual issues people are having with each part. This might be especially relevant when your symptoms are a sign of an underlying hormonal imbalances that may require individualized treatment.

But, as Abdullah says, looking at your skin, hair, and nail health together is a good jumping off point, even if it’s not always the ultimate answer. “Blanket prescriptions are a start towards treatment,” she says. Collagen supplements, for instance, “may help with some general issues with dryness of the nails and hair and premature aging of the skin, so most people can benefit from it.”  

“I always like to try to explain things from the basic science,” Skotnicki says. “Your skin, your nails, and your hair are all made up of the same stuff. So it would make sense if you're going to take something that treats all of them.” Skotnicki adds that so many women she sees are focusing so much attention on their skin, “so why not focus on all of them?”