Can white hair regain its natural colour?

The appearance of white hair, a process called canities, results from a gradual decline in melanin production by melanocytes, the cells responsible for pigmentation. With age, their number and activity naturally decrease, which explains why hair typically begins to whiten on average around the age of 35, sometimes later depending on the individual. However, certain internal or external factors can accelerate this process and induce a premature canities.

The stress is among the most studied causes: it can disrupt the hair follicle’s equilibrium by impairing melanocyte function, leading to a loss of pigmentation. Nutritional deficiencies may also play a role. A deficiency in vitamins B9, B12 or D, as well as in minerals such as selenium, iron or copper, can affect hair health. Copper, for example, is essential for tyrosinase activity, a key enzyme in converting tyrosine into melanin. Finally, the genetics and individual susceptibilities remain crucial factors: some individuals inherit a predisposition to develop white hair early in life, while certain autoimmune diseases such as the vitiligo may also be involved in the premature onset of white hair.

Many people with silvery hair would like to naturally regain their original hair colour. But is it possible? Yes and no..

In fact, it depends on the cause of canities. If your white hair is due to ageing, and therefore to a reduction in melanocyte activity, it is an irreversible phenomenon and your hair cannot naturally regain its original colour. Similarly, if the cause is a chronic disease, canities cannot be reversed. However, if stress is responsible for your white hair, some scientific evidence suggests that it is possible for them to recolour naturally.

Indeed, a recent study documented this natural repigmentation in 14 participants, with a mean age of 35 years. The researchers observed white hair returning to a pigmented state across several body regions, including the scalp, beard and even pubic hair. Although this phenomenon is rare and limited to a few isolated hair follicles, it demonstrates that the reversibility of canities is not merely theoretical. Some hairs displayed complex transitions, shifting from white to pigmented and then back to white within a single growth phase (anagen), emphasising the dynamic and transient nature of these pigmentary changes.

The mechanism underlying this repigmentation relies on melanocytes and their precursor cells. Researchers suggest that the recolouring could be triggered by the activation and differentiation of a subpopulation of immature melanocytes located in the outer root sheath of the hair follicle, or more likely by migrating transient melanoblasts. These cells would be capable of regenerating pigmentation in the hair by replacing depigmented melanocytes. Hence, repigmentation could occur over a short period—sometimes in as little as a few days—and reach full pigmentation in a median of around three months.

The study also quantified the rate of pigmentary changes. The depigmentation of white hair occurs at a variable rate, ranging from 0.2% to 14.4% loss of pigmentation per day, while natural repigmentation can occur at a similar or slightly faster pace, up to 30% faster on average. These observations show that recolouring is not a gradual reversal but a rapid, discrete and transiently reversible phenomenon, which can take place in the same time span as that required for the initial greying.

Finally, the researchers have explored the role of psychological stress in this process. Previous studies have shown that chronic stress and exposure to certain biological signals can accelerate hair depigmentation by depleting melanocyte stem cells. These results are consistent with empirical observations, where periods of intense stress appear to correlate with the appearance of white hair, while a reduction in stress may encourage natural repigmentation.

Hair whitening may not be inevitably irreversible: part of its dynamics could be influenced by psychological or environmental factors, although such repigmentation remains rare and confined to specific follicles.

The white hair are a natural sign of ageing and do not necessarily require concealment. Nonetheless, some individuals prefer to retain their original pigmentation, which is entirely reasonable. If your hair has greyed or turned white, you can restore your natural shade with hair dyes. We advise consulting a professional hairdresser for this rather than attempting a DIY colour treatment, unless you are certain of what you are doing. Indeed, it is common for hairdressers to see clients who have tried to colour their own hair but have achieved rather unsatisfactory results.

We can also mention certain topical products enriched with peptides and/or plant extracts that claim to repigment white hair. However, the results obtained by those who have tested them are uneven. Some have indeed observed a repigmentation of their white hair, whereas others have seen no change.

Note : The scientific literature reports a few isolated cases of individuals undergoing immunomodulatory or monoclonal antibody treatments who have experienced repigmentation of their grey hair. These events are, however, extremely rare and should in no way encourage the use of such medications in the absence of a medical condition and proper medical advice.

• RAWNSLEY J. & al. Hair biology: Growth and pigmentation. Facial Plastic Surgery Clinics of North America (2018).

• ROSENBERG A. M. & al. Quantitative mapping of human hair greying and reversal in relation to life stress. eLife (2021).

• PHILPOTT M. Watching hair turn grey. eLife (2021).

• JIANG G. & al. Reversing gray hair: Inspiring the development of new therapies through research on hair pigmentation and repigmentation progress. International Journal of Biological Sciences (2023).