Do hair vitamins really work? Dermatologists weigh in

While certain cuts and colors may come in and out of favor, long, luscious, healthy hair is always in style. Hair vitamins, whether multivitamins with biotin or stand-alone collagen supplements, promise to accelerate hair growth and keep strands shiny and strong. Dermatologist Dendy Engelman, MD, says the term often refers to formulas with biotin, vitamin B, vitamin D and keratin. But do hair vitamins really work?

It is not a simple yes or no answer. Dermatologist Mamina Turegano, MD, FAAD, says it depends on the ingredients. Regardless, she recommends seeking the help of a dermatologist or trichologist to create a personalized hair health plan. “Remember, hair loss is complicated and it’s probably best to see a dermatologist to make sure you get the underlying cause because some supplements may be better for your hair loss than others,” she says.

Go ahead, learn which ingredients dermatologists recommend and what underlying causes may be to blame for limp hair.

The science behind hair growth

To understand how hair growth is supported, it is crucial to have a basic understanding of the stages of the hair growth cycle.

“Hair grows in four phases: anagen, catagen, telogen and exogen,” says Turegano. “The Anagen phase is the stage of active growth – this is when the follicle produces new hair cells, resulting in visible hair growth and can last for two to seven years, depending on the genetics, age and location of the hair.” The length of time your anagen phase lasts determines how long your hair can grow. “During this phase, hair grows about one centimeter every month, or half an inch, and approximately 85 to 90 percent of scalp hairs are in the anagen phase at any given time,” she adds.

Next is the catagen phase: “This phase is also known as the transition phase between active growth and rest,” says Turegano. “During this phase, the follicle shrinks and detaches from the dermal papilla, a structure at the base of the follicle, which supplies nutrients to the growing hair – and only one to three percent of hairs are in the catagen phase for about two to three weeks.”

Then comes the telogen phase, where “the hair follicle is dormant and no longer produces new hair cells,” explains Turegano. “This phase lasts about three to four months and the hair is fully formed but not actively growing.”

Finally, the hair enters an exogenous phase. “This is when old hair falls out to allow new growth,” says Turegano. “At any given time, about ten to fifteen percent of the scalp is in the telogen phase.

Ingredients related to hair health

According to the pros, the common ingredients found in hair vitamins are for good reason – each delivers a targeted result to aid hair growth. But there are also off-the-radar ingredients that can be a real game changer and may not be found in the hair vitamin you’re reaching for. Here are the exact ingredients that the experts say can really deliver in terms of hair growth and determine if hair vitamins really work.

Biotin

“Biotin helps produce keratin, a protein that makes up hair, skin and nails, and specifically for hair growth, biotin increases keratin production, improves hair appearance and reduces breakage,” says Engelman. Turegano notes that while the vitamin B7 derivative is very common in hair-focus formulas, “the effectiveness of biotin is still debated,” as the available studies have small sample sizes. That said, Turegano says that supplementing with biotin can be beneficial for people with a deficiency. “But there are downsides—high doses can alter the results of lab tests for heart markers that are tested for heart attacks, so I don’t recommend taking more than 5,000 micrograms of biotin a day,” she says.

Niacinamide

Best known for its role in soothing skin care products, this B3 derivative improves blood circulation in hair follicles, which Turegano notes can promote healthy hair growth and improve hair texture.

Collagen

“Collagen is a protein found throughout the body, including in skin, bones and connective tissue,” says Engelman. “Since collagen is a component of hair follicles, this protein can help strengthen the hair shaft and prevent breakage, as well as supporting the structure and moisture of the skin and promoting a healthy scalp.”

Turegano points to a 2019 study published in the Journal of Drugs in Dermatology, which linked oral collagen supplementation to improvements in hair density and scalp health. “Researchers suggested that collagen’s supportive role in skin structure, combined with its antioxidant properties, may positively contribute to hair health.”

Turegano is a fan of hydrolyzed marine collagen peptides, a popular supplement to scoop into your morning smoothie or coffee. “These peptides provide the building blocks for strong hair and deliver moisture to the scalp,” she explains.

Vitamin A

Engelman explains that by boosting cell turnover, vitamin A can help keep hair moisturized and follicles healthy, which promotes overall hair growth. But other experts warn against experimenting with vitamin A. “Although vitamin A is great for the skin, its derivatives have been reported to cause hair loss when ingested,” says dermatologist Gina Ashforth, MD, FAAD. “Vitamin A is thought to stop the initiation of the anagen phase of the hair cycle and impair the anchoring of the hair in the telogen phase, ultimately leading to increased shedding.”

Vitamin C

It might be better known for its immune benefits, but vitamin C plays a key role in the production of collagen, a protein essential to hair health. “Vitamin C is known for its antioxidant properties and its role in collagen formation,” explains Engelman. “It supports hair health by promoting collagen production, which strengthens hair and improves its structure, helping to keep hair strong and visibly shiny.”

Vitamin E

“Vitamin E is a vitamin with powerful antioxidant properties that helps improve blood circulation to the scalp and ensures that the hair follicles receive more oxygen and essential nutrients,” says Engelman.

Keratin

“Keratin is a protein that creates structure for hair, skin, and nails, which can help strengthen hair, improve its appearance, and reduce breakage,” explains Engelman.

Saw Palmetto

“Saw palmetto promotes hair growth by reducing DHT, or dihydrotestosterone, a hormone that shrinks the hair follicle and leads to progressive hair thinning,” says Turegano. “This is good for male as well as female pattern baldness which is also referred to as androgenetic alopecia.

Zinc

“Zinc is an important mineral for building the integrity of the hair,” says Turegano. “It is a powerful inhibitor of hair follicle regression and accelerates hair follicle recovery.

She cites a 2016 study that evaluated serum zinc levels in patients with various types of hair loss, including alopecia areata and telogen effluvium. “The study found that alopecia patients had significantly lower serum zinc levels compared to healthy controls, and zinc supplementation was shown to improve hair regrowth in those with zinc deficiency.”

MSM

According to Turegano, this largely unknown ingredient with the full name methylsulfonylmethane is important because its main ingredient is sulfur, which is “necessary for the formation of hair cartilage and collagen in the skin,” she says.

Adaptogens

“Ashwagandha and shatavari are both adaptogens that help balance stress hormones and support healthy hair growth,” says Turegano.

Turmeric

“Turmeric, an ingredient found in turmeric, is a concentrated antioxidant that targets many of the root causes of hair loss and is five hundred times more powerful than turmeric alone,” says Turegano.

Vitamin D

“Vitamin D has anti-inflammatory and immunosuppressive properties and regulates the differentiation and proliferation of keratinocytes,” says Turegano. Of course, vitamin D supplementation is especially beneficial for those who are deficient.

Turegano cites a 2013 study published in Skin Pharmacology and Physiology that examined the relationship between vitamin D and hair loss in women with androgenetic alopecia. Researchers found that women with this condition had significantly lower levels of vitamin D compared to a control group, suggesting that the vitamin may play a role in hair loss.

Ashworth is skeptical of the available evidence, saying that although “vitamin D is produced in the skin and plays a role in regulating the hair cycle, limited research shows that vitamin D supplementation can improve hair growth in patients,” she says. “But because of the high prevalence of vitamin D deficiency in the general population, it is reasonable to check vitamin D levels in patients who have hair loss and treat the deficiency accordingly,” she says. That said, she cautions against taking vitamin D supplements without a deficiency, as too much vitamin D can do more harm than good.

Other factors underlying hair loss

While hair vitamins are marketed to everyone, it’s important to understand if you’re getting enough of them elsewhere in your diet. “There are two important situations to distinguish when it comes to vitamin supplementation for hair health—supplementation in an environment of known vitamin deficiency versus supplementation without a known deficiency,” says Ashworth. “Most hair supplements and vitamins are available over the counter and are not regulated by the FDA, making it easy to overdose or misdose a particular vitamin.

In addition, it is important, says Ashworth, to eliminate or identify underlying diseases. “Hair loss is an umbrella term that covers dozens of different conditions – and to get an accurate diagnosis, it helps to see if blood tests show an actual vitamin deficiency.”

While choosing a well-formulated hair vitamin is key, it’s important to consult a dermatologist to help choose the right combination. “Hair loss is complicated,” says Turegano. “That’s why I always recommend seeing a dermatologist to diagnose the root of the problem rather than looking for a quick fix.” Turegao suggests a multi-pronged approach: “I start with a thorough medical and family history, physical exam, and biopsy, if needed,” she says. “I also order lab work to check for underlying deficiencies or hormone imbalances and prescribe medications and suggest supplements and topicals, depending on my final diagnosis.

Engelman points out that there are both internal and external factors that can affect hair growth that need to be taken into account when choosing a hair vitamin. “Several factors can affect hair growth or disrupt hair growth stages, including hormonal changes, stress, lifestyle, metabolism, nutrition and aging,” says Engelman.

Takeaway

While not every hair vitamin works for everyone, certain ingredients can help support overall hair health, especially in people with vitamin deficiencies. Experts recommend consulting a dermatologist to check for vitamin deficiencies and determine any underlying causes of hair loss. Then together you can create an evidence-based plan that will work for your body’s needs.