Do Hair Growth Supplements Actually Work? Experts Weigh In

colorful pills vitamins scattered across pink table top

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You've heard of hair growth supplements that claim to give you thick, voluminous, and lustrous locks, but do these products actually work? Whether your hair is thinning or you just want to make your mane a little longer, hair-growth supplements are a well-known "treatment." Surely if there were a miracle-in-a-bottle pill, we'd all be on board and have a Rapunzel-like head of hair. Since that's clearly, and sadly, not the case, it leaves us feeling skeptical about whether or not we're just popping placebos. To answer our questions about hair-growth supplements, we turned to Dr. Rick Mizuguchi of Mount Sinai and Dr. Jennifer Herrmann of Moy Fincher Chipps.

Ahead, check out what you need to know about hair growth supplements and if they actually work.

Meet the Expert

  • Rick Mizuguchi, MD, is a board-certified dermatologist at Mount Sinai. He has an array of experience and particular expertise in cosmetic dermatology.
  • Jennifer Herrmann, MD, is a board-certified dermatologist and dermatological surgeon at Moy Fincher Chipps. Her specialties include laser treatments, reconstructive surgery, and cosmetic fillers.

What Are Hair Supplements Supposed to Do?

So, what exactly is the goal of using hair supplements? According to Herrmann, it really depends on the supplement. "Some supplements aim to improve one’s ability to tolerate stress (ashwagandha), others decrease inflammation (curcumin), some act as potent antioxidants (Vitamin E), others aim to reduce negative hormonal influences (saw palmetto), and some truly 'supplement' when there are vitamin or mineral deficiencies," she explains.

Woman healthy hair
t.maz / Getty Images

What Kinds of Hair Supplements Are There?

The types of hair supplements correlate with the different concerns you can come across, like the stress and hormonal imbalances we talked about above. Herrmann says supplements "can be grouped into those that replenish true deficiencies or insufficiencies, others that decrease inflammation, those that reduce oxidative stress, others that improve gut health (which in turn keeps fewer potentially inflammatory molecules from entering the body and effecting hair), those that reduce hormonal influences that impact hair loss, and those that decrease inflammation."

Do Hair Supplements Really Work?

We hate to bust this myth, but doctors say that hair supplements don't typically work unless you have a deficiency. "I don't really believe in any of the hair supplements that are out there," says Mizuguchi. "I do think that there is growing evidence that iron supplementation in some women with proven low ferritin [the protein that stores iron] levels should take supplementation as it is a vital cofactor for hair growth." However, Mizuguchi advises you to consult with a doctor before taking iron, since too much could lead to serious liver damage.

And while you've probably heard of biotin, a common ingredient in many hair supplement products, Mizuguchi is skeptical about its efficacy. "Biotin is another supplement that's often prescribed, especially for women of color, because it's supposed to be good for hair breakage. A lot of people mistake it as something that is good for hair thinning, but biotin deficiency causes hair breakage and not hair loss."

A lot of people mistake it as something that is good for hair thinning, but biotin deficiency causes hair breakage and not hair loss.

Hair shedding on hair brush
Cherayut Jankitrattanapokkin / Getty Images

If thinning hair is your issue, Herrmann says it's important to figure out why hair loss is happening before choosing a treatment path. "Are you losing hair because of changing hormones? Do you have a dermatologic condition causing discrete bald patches? Or have you over-processed to the point where your fried locks are brittle, breaking, and simply falling out? Better understanding the reason for your hair loss or thinning is important in determining what products might be helpful."

Talk with your doctor about the possible causes of your hair loss to determine which treatment suits your needs.

If you are in need of a thickening or growing agent regardless of the source of hair thinning, Rogaine is the most effective hair growth treatment on the market, according to both Herrmann and Mizuguchi. Herman says, "Although we don’t fully understand the exact mechanism behind Rogaine, studies have shown that it lengthens the hair’s growing phase and restores the size of shrunken follicles. This leads to gradual re-thickening of hair."

How Long Do Supplements Take to Work

As far as time goes, there's no one-size-fits-all answer. Herrmann explains that it can take weeks to months for supplements to work. "There is no quick fix!"

Woman looking at skin in mirror
Petr Kamanin / Getty Images

How Do I Know If I Have a Vitamin Deficiency?

There are quite a few signs that can give clues if someone has a severe vitamin deficiency. To get a better idea, Herrmann broke down a few common deficiencies and what they may cause.

Vitamin C deficiency: This causes hair-splitting, bleeding gums, nosebleeds, poor wound healing, and problems fighting infections."

Niacin deficiency: Can cause a scaly rash on sun-exposed skin, headaches, vomiting and diarrhea, fatigue, and depression.

Vitamin A deficiency: This can cause dry skin, dry eyes, night blindness, delayed growth, and breakouts.

"Vitamin deficiencies can be detected through blood work. They are uncommon except in those following strict diets, including vegan diets," Herrmann explains. "Vegans may need to supplement to make sure they obtain adequate amounts of vitamins that come from animal products. Also, strict sun avoidance can put someone at higher risk for vitamin D deficiency."

What's the Deal with Biotin?

Unfortunately, the buzz about biotin is just that—buzz. "Honestly, there is very little well-researched data on supporting that biotin improves hair growth in those who are not deficient," says Herrmann.

While biotin won't make your hair grow fuller and longer, it can help with hair breakage and split ends if you have a biotin deficiency.

What Are Some Other Ways to Make My Hair Grow?

If dedicated hair-growth supplements and chemical treatments aren't for you, keep scrolling for some alternatives!

Try a Multivitamin

Nature Made Women's Multivitamin Tablets
Nature Made Women's Multivitamin Tablets $8

Herrmann says that taking vitamins B6, B12, and folate may be helpful for hair growth. The vitamins generate red blood cells, which carry oxygen to all of the body's cells, including hair cells on the scalp. Additionally, multivitamins with iron could improve the effects of hair loss caused by an iron deficiency. Remember to see a doctor before taking any sort of supplement.

Eat Foods Rich in Fatty Acids

Herrmann says eating foods rich in omega-3 fatty acids, like salmon, "can also help dry, damaged hair by adding luster, elasticity, and shine to dull locks." Foods rich in protein also strengthen your tresses, which is key for having a lush set of strands.

Use a Thickening Shampoo

Not Your Mother's Way To Grow Long & Strong Conditioner
Not Your Mother's Way to Grow Long & Strong Shampoo $6

Fortified with vitamins, herbs, and bioactive ingredients, this shampoo strengthens hair and promotes healthy hair growth.

The Takeaway

The fact is, hair supplements can really only help if you have a vitamin deficiency. And to know that, you'll need to be diagnosed by a physician.

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