While there is still no approved treatment to permanently stop or reverse gray hair, scientists are getting closer. The breakthrough began with a happy accident. Dermatologists in Badalona, Spain, reported in JAMA Dermatology that a cancer immunotherapy drug darkened the gray hair of 14 lung cancer patients. That surprise finding spurred exciting new research. Fortunately, if you are dealing with premature graying, some of its causes are currently reversible.
To help you navigate the science, we will explore who tends to go gray first, why gray strands feel so different and how these new discoveries work. We will also break down the potential risks involved and look at the practical options available to you today.
What nationality goes gray first?
On average, people of European descent go gray first. A review in the Journal of Clinical and Aesthetic Dermatology found that White people often start in their mid-30s. Asian people tend to follow in their late 30s. Black people usually gray later, around the mid-40s.
Why the gap? A lot of it comes down to pigment. That same review points to larger pigment packets, called melanosomes, packed more densely into African hair. Researchers believe that extra pigment is why the color holds on longer. Of course, these are only averages. Genetics, overall health and stress can shift the timeline for anyone.
Is gray hair stronger or weaker?
Gray hair is usually weaker and more fragile, not stronger. Color comes from melanin, and the American Academy of Dermatology explains that strands turn gray once follicles stop producing it. When a strand loses melanin, it also loses some built-in structure and natural UV protection. Around the same time, the oil glands in your scalp slow down.
With less natural oil, gray hair tends to feel drier, coarser and more wiry, according to the Cleveland Clinic. It can also break more easily and lose moisture faster. The follicle itself does not fundamentally change. Still, the strand that grows out is more vulnerable to damage. That is why gray hair often needs gentler, more hydrating care.
How the gray hair treatment research works
The most talked-about lead came by accident. In a 2017 study, doctors treated lung cancer patients with immunotherapy. They noticed something strange. Some patients’ gray hair grew back dark. Immunotherapy drugs called checkpoint inhibitors unleash the immune system against tumors. Researchers think they may also reactivate the pigment cells that color hair.
Scientists like Melissa Harris at the University of Alabama at Birmingham now study immunotherapy specifically for graying. She believes losing melanocytes over time is “the major reason why we gray,” and that “reactivating those stem cells” is the way to bring color back. So far, that work is limited to cells and animal models.
The deeper science is also coming into focus. Your hair color comes from melanocyte stem cells in each follicle. A 2025 University of Tokyo study found that DNA damage can push these stem cells to mature and vanish. That process quietly drains the color from your hair, at least in mice. Lead researcher Emi Nishimura says the findings recast graying and melanoma as “divergent outcomes of stem cell stress responses,” as noted by Science Focus. In other words, going gray may sometimes be the body playing it safe.
Common side effects
One important caveat comes first. The cancer drugs that re-pigment hair are powerful immunotherapies, not gray hair treatments. Doctors prescribe them for serious illnesses, and they carry real side effects. Because they rev up the immune system, they can cause inflammation almost anywhere in the body. The most common effects are usually milder, though.
According to the National Cancer Institute, many patients develop a rash, itching or dry skin. Some notice pigment changes, including the hair re-darkening that sparked this research. Others develop light patches as the immune system targets pigment cells. Fatigue is also very common. Some people feel run down, achy or feverish, much like a mild flu. Nausea, a reduced appetite, and diarrhea can also show up. These effects vary a lot from one person to the next.
Rare or serious side effects
Less often, immunotherapy triggers serious inflammation. The American Cancer Society notes that it can affect the lungs, intestines, liver, hormone-producing glands, kidneys and other organs. These reactions are uncommon, yet they can turn severe and need prompt treatment. This is exactly why no one should chase cancer drugs for cosmetic reasons. The cosmetic option many people use, hair dye, carries smaller risks of its own. The U.S. Food and Drug Administration singles out PPD as the dye ingredient most often linked to allergic reactions. So a patch test before coloring is a smart precaution.
What to do if you notice symptoms
First, match your response to the situation. If you take immunotherapy for cancer, report any new symptoms to your oncology team right away. Do not wait, because early treatment keeps reactions from getting worse. If your concern is simply premature graying, see a doctor or dermatologist instead. Sudden or early graying can sometimes signal a vitamin deficiency or a thyroid issue worth checking. Above all, never try to treat gray hair with prescription cancer drugs. The risks far outweigh any cosmetic benefit.
Not all graying is permanent. When premature gray hair stems from a reversible cause, fixing that cause can sometimes restore color. As Dr. Michele Green, a board-certified cosmetic dermatologist in New York City, explains, advanced aging of the hair follicle from stress, smoking or imbalances can cut pigment production short, and “in most cases when the stressor is removed, hair pigment can return.”
Common culprits include low vitamin B12, iron, or vitamin D, an underactive thyroid, and smoking. Even stress may play a role. One Columbia University study found that easing stress allowed some gray hairs to regain their pigment. So if you are graying early, ask your doctor for a simple blood test. It is an easy and worthwhile first step.
Alternatives
For now, the proven options are simpler than a miracle cure. Hair dye remains the most reliable way to cover gray, and semi-permanent formulas offer a gentler route. Addressing reversible causes is the next best step, so check your B12, iron, vitamin D and thyroid. Quitting smoking and managing stress can also help protect the pigment cells you still have. For readers with textured hair, Green notes that the routine may not change dramatically, but it may need to happen more often. Because the scalp makes less oil and gray strands are even more porous, moisture is key to preventing breakage. She suggests lighter oils that hydrate without leaving hair dull or weighed down.
Researchers are testing other ideas, too. One Nagoya University study found that the antioxidant luteolin slowed graying in mice, though no human trial has confirmed that yet. None of these is a guaranteed fix. Still, science is moving fast, and a real gray hair treatment may not be far off.
Bottom line
There is no proven gray hair treatment that reverses graying for everyone, at least not yet. The accidental discovery that cancer immunotherapy can re-pigment hair is exciting, but it is early, and those drugs are far too risky for cosmetic use. Even so, Harris is hopeful, telling BBC Science Focus that “we have tools now that I think are getting us closer to it.” The practical wins today are simpler: cover grays if you like, and ask your doctor to check for reversible causes like low B12, iron, or thyroid problems.
Frequently Asked Questions
What vitamin deficiency causes gray hair?
Low vitamin B12 is the most established nutritional link, while shortfalls in vitamin D, iron (ferritin) and copper may also contribute.
Which parent do you inherit gray hair from?
Neither one specifically, because graying is polygenic and runs in families, with IRF4 the first gene ever linked to graying in a large human study.
Can gray hair be reversed?
Permanent graying cannot be reversed yet, but graying caused by stress or a nutrient deficiency sometimes regains color once the underlying issue is fixed.
Citations
Rivera N, Boada A, Bielsa MI, et al. Hair Repigmentation During Immunotherapy Treatment With an Anti-Programmed Cell Death 1 and Anti-Programmed Cell Death Ligand 1 Agent for Lung Cancer. JAMA Dermatology. 2017;153(11):1162-1165. https://pmc.ncbi.nlm.nih.gov/articles/PMC5817444/
The Institute of Medical Science, The University of Tokyo. Graying Hair May Reflect a Natural Defense Against Cancer Risk. Nature Cell Biology. Published 2025. https://www.ims.u-tokyo.ac.jp/imsut/en/about/press/page_00079.html
Maymone MBC, Abdat R, Goldberg LJ, Vashi NA. Hair Aging in Different Races and Ethnicities. Journal of Clinical and Aesthetic Dermatology. 2021;14(1):38-44. https://pmc.ncbi.nlm.nih.gov/articles/PMC7869811/
Desai DD, Karim M, Nohria A, et al. Premature hair graying: a multifaceted phenomenon. International Journal of Dermatology. 2025;64(5):819-829. https://pmc.ncbi.nlm.nih.gov/articles/PMC12008612/
National Cancer Institute. Immune Checkpoint Inhibitors. National Institutes of Health. https://www.cancer.gov/about-cancer/treatment/types/immunotherapy/checkpoint-inhibitors
American Cancer Society. Immune Checkpoint Inhibitors and Their Side Effects. American Cancer Society. https://www.cancer.org/cancer/managing-cancer/treatment-types/immunotherapy/immune-checkpoint-inhibitors.html
U.S. Food and Drug Administration. Hair Dyes. FDA. https://www.fda.gov/cosmetics/cosmetic-products/hair-dyes
American Academy of Dermatology. What Causes Gray Hair, and Can I Stop It? AAD. https://www.aad.org/public/everyday-care/hair-scalp-care/hair/gray-hair-causes
Cleveland Clinic. Gray Hair. Cleveland Clinic. https://my.clevelandclinic.org/health/symptoms/gray-hair
Iida M, Kagawa T, Yajima I, et al. Anti-Graying Effects of External and Internal Treatments with Luteolin on Hair in Model Mice. Antioxidants. 2024;13(12):1549. https://pmc.ncbi.nlm.nih.gov/articles/PMC11673595/
Adhikari K, Fontanil T, Cal S, et al. A genome-wide association scan in admixed Latin Americans identifies loci influencing facial and scalp hair features. Nature Communications. 2016;7:10815. https://pmc.ncbi.nlm.nih.gov/articles/PMC4773514/
TODAY / NBC News. A New Treatment for Gray Hair? Researchers Are Working on an Innovative Approach. Published 2026. https://www.today.com/health/skin-beauty/innovative-gray-hair-treatment-immunotherapy-rcna351138
BBC Science Focus. We May Finally Have a Way to Reverse Grey Hair. BBC Science Focus. https://www.sciencefocus.com/wellbeing/why-hair-greying-science-reverse
BBC Science Focus. Grey Hairs Grow When Your Body Shuts Down Cancer-Prone Cells, Study Suggests. Published 2025. https://www.sciencefocus.com/news/grey-hair-cancer
Rosenberg AM, Rausser S, Ren J, et al. Quantitative mapping of human hair greying and reversal in relation to life stress. eLife. 2021;10:e67437. https://elifesciences.org/articles/67437