Gray hair is a natural but inevitable sign that we’re aging. But new research suggests that it might not be so inevitable after all. By using drugs that stimulate part of the immune system, researchers think they may be able to restore pigment to hair that’s gone gray to prevent or even rever se the process. The idea started with an unexpected finding in cancer patients. In a study published in JAMA Dermatology in 2017, researchers found that 14 lung cancer patients who were treated with an immunotherapy drug also experienced the re-pigmentation of their gray hair. The researchers weren’t exactly sure why the treatment had this side effect on gray hair, but thought it could be used as a marker that the drug was working in cancer patients. But others, like Melissa Harris, Ph.D., at the University of Alabama, have begun investigating the use of immunotherapy specifically to treat gray hair. What Causes Gray Hair? Hair goes gray as we age due to changes in the pigment-making stem cells called melanocytes that live in and around your hair. Every hair goes through a normal cycle consisting of a growth phase followed by a resting phase, then finally falling out over the course of years. Each time the hair starts a new cycle, pigment (melanin) is created. When that happens, the melanocytes that normally live in the midpoint of your hair, migrate to the follicle to produce pigment, Dr. Jonathan Zippin, dermatologist at Weill Cornell Medicine, told TODAY.com previously. But after seven to 15 rounds of this cycle, those cells stop producing more melanin, the American Academy of Dermatology explains. You’ll notice graying start when “those melanocytes are no longer moving and populating the bottom of the hair,” Zippin said. Stress can also lead to graying by causing your body to release norepinephrine, a hormone. This chemical spurs the melanocytes to leave the hair follicle, contributing to gray hair, the AAD says. Can Immunotherapy Reverse Graying? Harris believes that losing melanocytes as we age is “the major reason why we gray,” she explained in a TODAY segment aired June 16. Getting the pigment back, then, is a matter of rejuvenating that pigmentation system by “reactivating those stem cells,” she explained. So far, Harris and her team have only tested the immunotherapy treatment in cells and animal models. But the results have been as dramatic as those seen in the 14 cancer patients. More and larger-scale research in humans will be needed before the treatment has a chance of hitting the market. For now, there aren’t any approved treatments to reverse or stop hair from going gray. And certain underlying health conditions or stressful life events may make premature graying more likely for you. If you’re concerned the amount of gray in your hair may indicate a medical problem, talk to a dermatologist or other health care provider. This story first appeared on TODAY.com. More from TODAY: Is the Viral Trader Joe’s $10 Vitamin C Serum as Good as Luxury Skin Care? We Tried It What’s the New Sunscreen Ingredient, BEMT? Experts on Why Bemotrizinol Is Different — and Better Best of the Walmart Deals Event: Michael Kors Bags, Cooling Bedding, More ...read more read less