Skeptics (among them, Dr. Wesley) are starting to come around after a 2014 randomized double-blind study published in the American Journal of Clinical Dermatology found a “statistically significant” difference in hair density for women who used a laser comb compared with those who used a sham device. (“Comb” is something of a misnomer. The device looks like a hairbrush crossed with a cordless phone; it is glided back and forth across the scalp, roughly a half-inch at a time, usually about 15 minutes three times a week.)
When it comes to a hair growth shampoo, you have two options: prescriptions or over-the-counter treatments. Prescription shampoos like ketoconazole are anti-androgenetic, meaning they prevent testosterone and dihydrotestosterone (DHT), two hormones associated with hair loss by targeting hair growth at the site of the follicle and helping to interrupt the hormone cycle locally that causes thinning,” explains Dr. Schweiger. “Over-the-counter growth shampoos typically contain amino acids and antioxidants to provide the components to rebuild hair as well as reduce damage and inflammation.”
“There’s people selling pills and creams and lotions and whatever else, and sometimes you can’t even trust what ingredients they have in there,” he warned us when we spoke to him over the phone. Key takeaway: The hair loss industry is crazy dishonest, so we eliminated any treatments (especially homeopathic methods) that aren’t based in concrete, peer-reviewed science.
Castor oil, as some might already know, is one of the most popular all-natural "panaceas." Go ahead, Google it: What you'll find is article after article about how the viscous oil can help with shedding, breakage, and regrowth. But unlike rosemary oil and vitamin B5, both of which have studies that back up their aid in hair growth, scientific evidence surrounding castor oil is lacking. (Any testimonials about castor oil for hair growth are anecdotal, coming mostly from blogs, Reddit, and YouTube.)
The follicles on the sides of the scalp are more genetically resistant to DHT, which is why male pattern baldness often results in a “crown” of hair. But its downsides are serious. “With women, finasteride is not an option,” says Dr. Wolfeld. “It’s not FDA-approved for women to take, so we don’t prescribe it.” In fact, due to the drug’s effect on hormone levels, pregnant women are advised to not even touch broken or crushed tablets.
The second member of “the big three” and another extremely effective FDA approved hair loss treatment is minoxidil. Minoxidil was originally an oral medication for high blood pressure. But after a while, patients started reporting hair growth — all over their bodies. And not much longer after, the minoxidil topical solution for treating hair loss was born.
The other main hair-loss treatment that was recommended by all four dermatologists I interviewed is finasteride, often called by its brand name Propecia. This FDA-approved medication is only available with a prescription, but these days, it’s found as a generic and ordered online after a virtual consultation, through start-ups like Hims, Keeps, and Lemonaid.
Minoxidil (Rogaine, generic versions). This drug was introduced as a treatment for high blood pressure, but people who took it noticed that they were growing hair in places where they had lost it. Research confirmed that a 2% solution of minoxidil applied directly to the scalp could stimulate hair growth. How it works is still not clear. Two double-blind studies of women ages 18 to 45 demonstrated its effectiveness. In one study, 13% of female minoxidil users had moderate hair growth, and 50%, minimal growth (compared with 6% and 33%, respectively, in the placebo group). In the second study, 60% of women in the minoxidil group reported new hair growth, compared with 40% in the placebo group. As a result of these studies and others, over-the-counter 2% minoxidil is FDA-approved for treating androgenetic alopecia in women.