Online and off, many people have credited supplements with helping them overcome hair loss. Videos abound on TikTok of people saying that brands such as Nutrafol and Viviscal made their hair thicker, healthier and shinier.

So do these hair growth supplements really work?

Such supplements often contain vitamins (like biotin and vitamins A, C and D), minerals (like zinc and selenium) and extracts from plants including turmeric and horsetail. They can also contain collagen and even shark cartilage and oyster extract powder.

In some cases, they might help to regrow lost or thinning hair. But they have not been well-studied and may not be as effective as prescription treatments, like minoxidil (also sold over the counter as Rogaine) or oral finasteride, said Dr. Melanie Tawfik, a dermatologist at MedStar Health in Chevy Chase, Maryland.

They can also have some downsides, said Dr. Ajay Kailas, a dermatologist and founder of the teledermatology company VidDerm. People taking Nutrafol are instructed to take four capsules a day, and a one-month supply costs nearly $90.

“That’s a deal breaker for a lot of my patients,” he said.

The science

Little peer-reviewed research has been conducted on these supplements. Academic researchers have studied some of their individual ingredients, but the key studies that have analyzed the effectiveness of popular hair loss supplements have been funded by the companies that market them. In certain cases, the researchers involved worked for the company, too.

“That’s always a potential bias that we don’t love to see,” Tawfik said.

In one clinical trial published in 2021, for instance, researchers — including one who worked for the company that makes Nutrafol — tested the supplement’s effects on 40 women between the ages of 40 and 65 with self-reported hair thinning. It found that over six months, those who took Nutrafol had significantly more hair growth than those who took a placebo. In a follow-up study published in 2022, a similar research team followed the same women for another six months and reported continued improvements in their hair growth, quality and shedding.

In a 2015 clinical trial of 36 women funded by Viviscal’s then parent company, researchers reported that those with self-reported hair thinning who took Viviscal had more hair growth after three and six months than women who did not use any hair growth products.

It’s unclear, however, if taking a simple multivitamin supplement would have been just as effective, said Dr. Angela Lamb, a dermatologist at Mount Sinai Dermatology in New York City.

When male or female patients complain of hair loss, dermatologists typically check whether they are deficient in vitamin D, iron and zinc, which can cause hair loss. They also check thyroid function, which can influence hair growth, Lamb said. Deficiencies can sometimes be addressed with vitamin or mineral supplements, while thyroid issues are often treated with prescription medications.

Nutrafol and Viviscal contain zinc, and Nutrafol contains vitamin D, so it could be that some or all of the women in these trials were deficient and would have experienced the same benefits by taking a much cheaper vitamin and mineral supplement, Lamb said.

More than vitamins?

Kailas said that he has seen hair regrowth among his patients who have taken hair loss supplements like Nutrafol, even when they are not vitamin deficient. He also uses Nutrafol himself.

Still, many of the ingredients in hair growth supplements are “not well studied,” and what they do is not well understood, Tawfik said.

Nutrafol contains saw palmetto, a plant extract that might help with hair regrowth, according to limited evidence. In one 2020 review of nine studies, researchers reported that topical or oral versions of saw palmetto might be an effective treatment option for patients with androgenetic alopecia and telogen effluvium, two common forms of hair loss. The substance is thought to work by preventing the hormone testosterone from converting to DHT, a process that can cause hair loss, Kailas said.

Collagen, a protein believed to support hair growth, is also often included, though little research on its effects on hair has been done. Many hair supplements additionally contain biotin, but that doesn’t seem to help with hair growth, Kailas said. “That’s a big myth.”

Tawfik also pointed out that Nutrafol and other hair supplements will not improve scarring-related hair loss, such as cicatricial alopecia, in which the immune system destroys hair follicles.

The bottom line

Nutrafol, Viviscal and other hair growth supplements are not tightly regulated by the Food and Drug Administration, Tawfik said. They have not received FDA approval for treating any medical conditions and have not undergone the same safety and efficacy testing as drugs, she said.

But that doesn’t mean you need to avoid them outright. While expensive hair loss supplements are not Tawfik’s “go-to” treatment option, she said, she often does mention them to patients as an alternative to prescription drugs. They haven’t been found to be dangerous, and there is at least “some evidence that they can work,” she said.

So for some people, they can be worth a shot.