Caffeinated Haircare Products Unlock Crazy-Fast Hair Growth—Here's Why

According to board-certified dermatologist and founder of Facet Dermatology, Geeta Yadav, MD, caffeine offers multiple benefits to the hair and scalp. First, it functions as an antioxidant. "As an antioxidant, it helps defend hair and scalp from free radical damage, allowing for smoother, shinier, and healthier-looking hair," she says.

That being said, she admits that the "most interesting" benefit is that it can help with hair growth, which it does by stimulating and actually enhancing blood flow. "In a study, caffeine showed the ability to improve skin barrier function, stimulate blood circulation, and promote new hair growth. It also inhibits phosphodiesterase, which means it can enhance blood flow, too, making for an excellent foundation for healthier hair growth." 

Why is blood flow important, According to Brendan Camp, MD, double board-certified dermatologist, "Better blood circulation on the scalp may improve oxygenation and the delivery of nutrients to hair follicles." In turn, "Improved oxygenation and delivery of vitamins and nutrients to hair follicles may reduce the impact of oxidative stress on hair follicles. Oxidative stress refers to the damage caused by free oxygen radicals, which can have a negative effect on cellular structures." In other words, more blood flow means more nutrients and less damage to hair follicles. And as we all know, happy hair follicles result in strong, shiny hair. 

The best part about caffeine is that there really aren't any negatives associated with its use in topical hair care products. "Most people will not have any issues or negative side effects when using a scalp treatment containing caffeine," Yadav says. "It’s worth noting that a lot of scalp treatments that stimulate hair growth feature ingredients like tea tree and peppermint, which can irritate some skin if it's in higher concentrations. I’d recommend patch testing on your inner arm before committing to full-scalp application." 

Camp agrees, saying it's generally safe. "Those with sensitive skin or a known skin reaction to caffeine may want to avoid caffeine-based hair products or do a test spot prior to application," he says. 

Both dermatologists say it can be used daily. In fact, Yadav recommends using it daily for best results. And while there are many caffeine-infused shampoos on the market, she recommends reaching for a leave-on product, like a scalp serum, instead. "Any product that you leave on will be more beneficial than one that you wash off," she says. "While you’ll see some benefit from a shampoo, especially if you let it sit on your scalp for two minutes before rinsing, a serum that you massage in and leave on overnight will deliver the best results."