Thiamine Boosts Hair Health From the Inside Out—Here's How

Experts share all the details on this antioxidant.

Woman with an afro

Javier Díez / Stocksy

Whether your hair is pin-straight, wavy, curly, or coily, there’s one thing practically everyone has in common: We all want healthier, stronger hair. And while it seems everyone you ask has their own set of tips and products they swear by, thiamine is an especially versatile ingredient that can help get you the hair of your dreams.

Thiamine has been a go-to for those with thinning hair due to its strengthening powers. “Thiamine is a water-soluble vitamin also known as vitamin B1, the first to be discovered among the B complex vitamins,” says Kari Williams, Ph.D. In addition to being available in supplement form, thiamine can also be found in shampoos and scalp treatments, such as serums, lotions, masks, and tonics.

One of the perks of thiamine is that it plays well with others. “Thiamine can be used with any other hair care ingredients,” says Gary Goldenberg, MD. “I recommend it for those with dry and damaged hair, as it can help with hair breakage.”

Meet the Expert

  • Kari Williams, PhD, is a board-certified trichologist, licensed cosmetologist, and a member of DevaCurl's Expert Curl Council.
  • Gary Goldenberg, MD, is a cosmetic and medical dermatologist based in New York City. He has his own practice, Goldenberg Dermatology, and is the assistant clinical professor of dermatology at Mount Sinai Hospital's Icahn School of Medicine.

Curious to see if this versatile ingredient can nourish your strands to their best state? Ahead, get our experts' thoughts on the benefits and uses of thiamine for hair.

Thiamine for Hair

Type of ingredient: Antioxidant and vitamin

Main benefits: Boosts scalp and hair health, as well as helps with hair loss.

Who should use it: Anyone looking to improve hair growth or to keep their scalp healthy.

How often to use it: As often as needed—suitable for daily use.

Works well with: Most other ingredients.

Don't use with: Horsetail and areca (betel) nuts. It’s also known to interact with other herbs and supplements, so if taking thiamine orally, consult with your doctor first.

What Is Thiamine?

Thiamine is another name for vitamin B1. “It’s part of the B complex valuations and is found in many food sources, such as nuts, legumes, and meat,” Goldenberg says. “Vitamin B1, like all the B complex vitamins, is important for metabolism. Specifically, it’s needed to metabolize glucose to produce energy.” 

Overall, thiamine for hair is very safe. “Possible side effects include an allergic reaction or skin irritation,” Williams says. Since it’s a water-soluble vitamin, one cannot take too much, according to Goldenberg, though he warns there’s one caveat: “Unless there’s severe renal/kidney disease—then you have to be very careful.”

Benefits of Thiamine for Hair

Thiamine improves blood flow, supports the brain and nervous system, and helps with the synthesis of amino acids, according to Williams. “The role B1 plays in the metabolism of macronutrients and energy production is essential for almost every cell in the human body,” she adds. These processes lead to several key benefits of using thiamine for hair health.

  • Promotes a healthy scalp: “Thiamine reduces the constriction of blood vessels, which improves blood flow and the circulation of oxygen and other vital nutrients to the hair follicle,” Williams says. “This provides support for hair growth and a healthy scalp.” 
  • Prevents hair loss: “Vitamin B deficiency, including thiamine, has been associated with hair loss,” Goldenberg says. “Therefore, replacing vitamin B1 can help restore hair loss and improve hair health in general. In my experience, vitamin B complex injections (this includes thiamine) can help hair loss even in those with normal vitamin B1 levels.” 
  • Strengthens brittle hair: Williams explains that because thiamine is an antioxidant, it helps protect hair from damage. Damaged hair is brittle hair, so over time, hair will become healthier from the inside out.  
  • Adds shine: Since thiamine boosts overall hair health, it’s likely to leave locks glossier.
  • Boosts growth: Thiamine helps achieve a healthy scalp, which is essential to hair growth.

Which Hair Types Should Use Thiamine?

While many ingredients are likely to help some hair types more than others, thiamine has the potential to benefit a particularly wide range. “Thiamine is best for all hair types, especially those who may be experiencing thinning, dry, or brittle hair,” Williams says. “The antioxidant properties of thiamine help protect the hair from accumulated damage and promote hair growth through healthy blood flow.”

How to Use Thiamine for Hair

Popping thiamine as a pill is the top choice since to get the most benefit from this nutrient, it’s best to take it as a vitamin supplement. “Because thiamine is a vitamin it is much different from other ingredients typically used in hair care products and is most effective for hair health when taken as a supplement,” Williams says. “This water-soluble vitamin will absorb easily into the bloodstream. Strong, healthy hair grows from the inside out.”

In addition to oral vitamins, Goldenberg says you can also take thiamine as injections of vitamin B complex. However, he notes that applying this ingredient directly to hair isn’t a great idea. “I don’t think this [method] is effective for hair loss and don’t recommend it to patients,” he says. “Many hair care products include thiamine as they claim it helps with hair loss. That may or may not be true. However, it can help strengthen hair and prevent hair breakage.”

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