I'm A Plastic Surgeon: This Is What I Recommend If You Have Thinning Hair 

Anthony Youn, M.D., may be a board-certified plastic surgeon, but he prefers long-term recommendations for skin longevity (hence, the holistic in his professional title) over "quick" fixes under the knife. In fact, it's his personal goal to keep patients out of the operating room: He does perform surgery on a select bucket of patients, sure, but only as a last resort. Until then, he likes to stick to proactive measures and less-invasive treatments—so, naturally, his recommendations for thinning hair align with this holistic philosophy. 

"We know that vitamin D is very important for the hair follicle and therefore hair growth," seconds board-certified dermatologist and hair care expert Raechele Cochran Gathers, M.D., on an episode of Clean Beauty School. "In fact, vitamin D is one of the fat-soluble vitamins needed for maintaining and creating functioning hair follicles." (Find our favorite vitamin D supplements here).

Another treatment Youn loves for thinning hair? Low-light laser therapy. While we need more research, the current data seems encouraging: Specifically, one study found that women who received red light therapy at 650 nm every other day for 17 weeks experienced a 51% increase in hair density1, and another research review touted red light therapy as safe and effective for promoting hair growth2 in both men and women. 

"Low-light laser therapy is basically like the laser of a laser pointer," Youn explains. "It doesn't create any heat. You can have it pointing at your skin for hours, and you're not going to get a burn." The theory, he continues, is that these low-light lasers can create changes in your follicle's growth phase, which can help to thicken and grow hair. 

On to the topicals. "There's actually something very natural that people can use: a topical rosemary oil," Youn says. In fact, a 2015 randomized comparative trial found that rosemary essential oil was just as effective3 as minoxidil (the active ingredient in many commercial hair-growth products) for reversing hair loss caused by androgens—also known as male- or female-pattern baldness—after six months. 

"However, a significant difference between the two is that [minoxidil] had a higher rate of itching and discomfort of the skin, whereas rosemary oil did not," Youn adds regarding the study. "So that is definitely a very reasonable option for people who want to stay natural and have some thinning hair issues."