Can Gray Hair Ever Turn Back to Its Natural Color?

Usually not. Once a follicle has used up its pigment stem cells, the hairs it grows stay gray, and there is no proven treatment that brings color back. Researchers have recorded rare cases of gray hairs regaining color, and the scientists who studied them say this is more likely early in the graying process.

Why gray hair usually stays gray

Cleveland Clinic states that if your hair turns gray, it is unlikely to regain its color naturally, because cells that stop making melanin usually do not start again. A 2013 review in the Indian Journal of Dermatology, Venereology and Leprology describes graying as usually progressive and permanent.

The reason is in the follicle. Each follicle keeps a small supply of melanocyte stem cells, which provide fresh pigment cells for every new hair. A 2024 review in the Journal of Investigative Dermatology states that graying becomes permanent only when these stem cells are depleted. A 2020 study in mice, published in Nature, found the same result: when stress used up the stem cells, the loss of pigment was permanent.

There is a second limit. The part of a hair above the skin has no living cells, according to a 2013 review in the International Journal of Trichology, so it is not thought to be able to change on its own. Any return of color would show at the root, in new growth. Our page on how hair gets its color explains this in more detail.

The hairs that did regain color

A 2021 study in eLife, led by Martin Picard at Columbia University, looked for this directly. The team measured color along single hairs in tiny slices. According to Columbia, each slice was about 1/20 of a millimeter wide and stood for about an hour of growth.

They studied 397 hairs from 14 volunteers, seven women and seven men, aged 9 to 65. Some hairs were white along one stretch and dark again closer to the root. This happened in both sexes, in several ethnic groups, at different ages and on different parts of the body. In one case, five hairs on one person's head turned dark again during a vacation, at the same time.

The authors describe these reversal events as rare. They write that such events are more likely to happen in the early stages of graying. That is one reason they chose volunteers at the beginning of the aging process rather than older adults. The link with stress is covered in our page on stress and gray hair.

Why this is unlikely to help hair that has been gray for years

The Columbia team built a computer model of their results. It suggests that graying works like a threshold, and that a hair near that threshold can sometimes move back across it for a while. Picard explained the limits in Columbia's announcement:

"But we don't think that reducing stress in a 70-year-old who's been gray for years will darken their hair or increasing stress in a 10-year-old will be enough to tip their hair over the gray threshold."

He added that reducing stress "won't necessarily turn your hair to a normal color." In other words, a few hairs that have only just turned gray may recover. A head of long-gray hair is a different situation.

Medicines that darkened gray hair

Doctors have also seen gray hair darken as a side effect of some medicines. A 2023 review in the International Journal of Biological Sciences lists several reports:

Medicine type	What was reported
Cancer immunotherapy for lung cancer (anti-PD-1 and anti-PD-L1 drugs)	Hair regained pigment in a series of 14 patients
Imatinib, a drug for chronic myeloid leukemia	9 of 133 patients in one study had hair regain pigment
Dupilumab, used for atopic dermatitis	One reported case
Adalimumab, used for rheumatoid arthritis	One reported case
Tamoxifen, used for breast cancer	One reported case

These drugs were given for other illnesses, and the change in hair color was a side effect. A 2024 review notes that several drugs and hormones have caused repigmentation, which points researchers toward biological pathways worth studying. These medicines are not treatments for gray hair. The same 2023 review states that there is no effective countermeasure for gray hair other than hair dyes.

What about vitamins and health problems?

Some early graying is linked to a health problem. Cleveland Clinic says lower levels of vitamin B12 and iron are linked to premature graying, and a 2018 review lists low thyroid hormone as a cause.

The American Academy of Dermatology (AAD) notes that some research suggests gray hair may grow in with color again, but only under specific conditions, such as reducing emotional stress or treating an underlying health condition. It says more research is needed. It also states that there are currently no effective medical treatments to add color back to hair. If you went gray early, suddenly or in patches, a doctor can look for a cause. This post is general information, not medical advice.

What actually changes the color you see

For now, hair color products are the practical choice for people who want less gray. A 2018 review in the International Journal of Trichology describes hair dyes as the main option for cosmetic concerns, and the 2013 review in the Indian Journal of Dermatology, Venereology and Leprology describes hair colorants as a way to camouflage gray. They cover gray hair. They do not restore the follicle's own pigment.

Our guide to ways to cover gray hair compares the main types, and why gray hair resists dye explains why gray can be harder to color. For the other side of the question, see our page on gray hair myths, and for the full science, read why hair turns gray.

LIUMIQ is developing a gradual color product for gray hair. It is a hair color, not a treatment, and it does not change how hair makes pigment. It is not for sale yet. Join the waitlist to follow the work.