Immunotherapy Shows Promise for Reversing Gray Hair: From Cancer Side Effect to Potential Treatment
Key Insights
A 2017 JAMA Dermatology study found that 14 lung cancer patients treated with immunotherapy (search) experienced re-pigmentation of their gray hair (search) as an unexpected side effect.
Researchers, including Melissa Harris, Ph.D. at the University of Alabama at Birmingham, are investigating immunotherapy (search) to reactivate melanocyte stem cells and restore hair pigment.
Gray hair (search) results from melanocytes (search) no longer migrating to the hair follicle base to produce melanin after repeated hair cycles, with stress also contributing via norepinephrine release.
A surprising observation in cancer patients has opened an unexpected frontier in the science of hair graying: immunotherapy (search) drugs may hold the key to reversing gray hair (search). The discovery, first documented in a 2017 study published in JAMA Dermatology, found that 14 lung cancer patients treated with an immunotherapy drug experienced re-pigmentation of their gray hair—a side effect that has since spurred dedicated research into whether the immune system can be harnessed to restore natural hair color.
The finding has captured the attention of researchers like Melissa Harris, Ph.D., at the University of Alabama at Birmingham, who is now investigating immunotherapy (search) specifically as a potential treatment for gray hair (search). "Getting the pigment back is a matter of rejuvenating that pigmentation system by reactivating those stem cells," Harris explained in a TODAY segment aired June 16.
The Biology Behind Graying Hair
Hair graying is predominantly driven by the behavior of melanocytes (search), the pigment-producing cells that reside in hair follicles. Dr. Jonathan Zippin, a dermatologist at Weill Cornell Medicine, describes melanocytes as living at the midpoint of the hair. When they need to replicate, these cells migrate to the base of the hair follicle to produce melanin—the pigment responsible for hair color.
Graying occurs when "those melanocytes (search) are no longer moving and populating the bottom of the hair," Zippin told TODAY.com. After approximately seven to 15 cycles of hair growth and shedding, these cells stop producing more melanin, according to the American Academy of Dermatology. When no melanin is present at all, the hair appears white.
Two distinct types of melanin dictate hair color, and the amount and mixture of these determines whether hair is black, brown, red, or blonde. The age at which graying begins—typically in one's 30s or 40s, per the Cleveland Clinic—and the extent of graying varies significantly between individuals.
Stress also plays a documented role. The American Academy of Dermatology notes that stress triggers the release of norepinephrine, a hormone that spurs melanocytes (search) to leave the hair follicle, contributing to gray hair (search). A 2021 study found that stress can lead to gray hair in humans, and removing that stress appeared to reverse the process in some cases—though effects were temporary and limited to certain age groups and only a few hair follicles.
From Cancer Treatment Side Effect to Research Target
The 2017 JAMA Dermatology study initially interpreted the re-pigmentation effect as a potential marker that immunotherapy (search) was working in cancer patients. But Harris and her team saw a different opportunity: could immunotherapy be developed specifically to address gray hair (search)?
Harris believes that losing melanocytes (search) as we age is "the major reason why we gray." Her approach centers on reactivating the melanocyte stem cells that normally replenish the pigment-producing cells in hair follicles. So far, this research has only been conducted in cells and animal models, but Harris describes the results as being as dramatic as those seen in the original 14 cancer patients.
More and larger-scale research in humans will be needed before any such treatment could reach the market.
The Current Landscape: Serums, Supplements, and Skepticism
The pursuit of gray hair (search) reversal has not gone unnoticed by the consumer market. Online search interest in anti-gray hair serums has climbed 280% in the United States over the past year alone, according to an NBC News analysis. Products containing ingredients like caffeine, peptides, and vitamins promise to reduce the appearance of grays and renew hair color, with some claiming to have research supporting their assertions.
However, dermatologists remain skeptical. "Whether the melanocytes (search) are actually nudged is questionable. ... I don't know that we have any definitive science to say that that's happening," said Dr. Mona Gohara, a board-certified dermatologist based in Connecticut.
Regarding stress-induced graying, Zippin added: "Theoretically, if gray hair (search) is caused by stress and those stressors are removed, that could reverse gray hair, but has that been done pharmacologically? No."
As for vitamin B12 and other supplements marketed for gray hair (search), experts are equally cautious. While vitamins B, A, and biotin have been shown to play a role in hair growth and follicle health, according to the Cleveland Clinic, there are no scientific studies demonstrating that any supplements—including vitamin B12—will prevent or reverse gray hair in humans.
"I think it's fair to say that we don't truly understand what causes gray hair (search). Therefore, it's hard to know whether any particular product will be successful because we don't know what mechanism we're really trying to reverse," Zippin said.
Safety Considerations and the Road Ahead
The U.S. Food and Drug Administration does not review anti-gray hair (search) products for safety before they reach the market. Gohara considers most of these products to be low risk and "pretty safe to try," though potential side effects may include scalp irritation from serums or gastrointestinal issues from supplements. Allergic or adverse skin reactions remain possible with any new topical product.
For now, no FDA-approved treatments exist to reverse or stop hair from going gray. The immunotherapy (search) approach being pursued by Harris and colleagues represents a scientifically grounded pathway, but it remains in early-stage research. As Zippin noted, the fundamental challenge persists: "We don't truly understand what causes gray hair (search). Therefore, it's hard to know whether any particular product will be successful because we don't know what mechanism we're really trying to reverse."