White hair can be a source of discomfort for some people, leading them to seek innovative hair treatments. But is it really possible to repigment white hair? Let's explore the various options together.
Treatment: Is it possible to repigment white hair?
- Where do white hairs come from?
- What repigmentation treatments are currently available?
- An overview of repigmentation effect drugs
Where do white hairs come from?
The emergence of white hair, commonly referred to as canities, is a phenomenon often associated with a decrease in melanin production by melanocytes and a gradual reduction in their number. This natural process typically occurs around the age of 35, or later. It's also worth noting that the appearance of white hair can be influenced by other internal or external factors. Studies have, for instance, shown that prolonged stress can impact the functioning of melanocytes, thereby disrupting melanin production and leading to a decrease in hair pigmentation.
In addition to stress, deficiencies in vitamins B9, B12, D, selenium, iron, or copper can also play a major role in hair color loss. The underlying mechanisms vary depending on the nutrient involved. For instance, copper promotes the activity of tyrosinase, an enzyme essential for the conversion of tyrosine into melanin. Lastly, the early onset of white hair can be influenced by genetic factors or associated with an autoimmune disease such as vitiligo.
What repigmentation treatments are currently available?
Promising a gradual, natural, and most importantly, non-aggressive recoloration for white hair, repigmenting treatments are formulated to boost the synthesis of melanin by the melanocytes in the hair bulb. They contain peptides for this purpose, which are small proteins that penetrate the scalp to the melanocytes to restart their activity. However, opinions regarding the results obtained are mixed. Some say they have indeed observed a repigmentation of their white hair, while others have seen no change.
One can hypothesize that the following reason is at the root of these varying results: the onset of gray hair is not solely linked to a loss of melanocyte activity, but also to a gradual decrease in their number. Indeed, these cells are naturally destroyed as they undergo oxidative stress (UV rays, pollution, etc.). Therefore, if we assume that the peptides used by repigmenting treatments are indeed capable of reaching the melanocytes and restarting melanogenesis, they will only have an effect if there are remaining melanocytes at the hair bulb level. This is why such repigmenting treatments remain uncertain to this day.
An overview of repigmentation effect drugs.
Clinical studies have reported that the oral intake of certain medications can repigment white hair, even when the purpose of these treatments was sometimes entirely different. Among the most commonly found molecules are anti-inflammatories, melanogenesis stimulators, and vitamins. Here is an overview of these different compounds and their effects.
The potential of anti-inflammatories to combat white hair has been investigated in several studies. One of the first to mention it dates back to 1986. Conducted on 37 healthy individuals aged 10 to 20 years with premature white hair, this study showed that the intake of psoralen and exposure to UVA light allowed for complete repigmentation of the hair in 46% of the patients and partial repigmentation in 19%. This method, called PUVA therapy, is currently used to reduce the symptoms of psoriasis and vitiligo. It is unlikely that it will ever be used to repigment white hair, as one of its side effects is an increased risk of developing skin cancer.
Other cases of repigmentation of gray hair caused by anti-inflammatory drugs have been reported sporadically. Drugs that activate retinoic acid receptors, specifically acitretin and etretinate, have been associated with repigmentation of gray hair in two patients with pityriasis rubra pilaris and one patient with psoriasis after 6 to 12 months of treatment. However, the associated mechanisms have not been detailed.
Several medications have also demonstrated an effect on melanogenesis. In a study involving patients receiving imatinib for chronic myeloid leukemia, 7% of the 133 patients exhibited repigmentation of gray hair 2 to 14 months after the start of treatment.
Another tyrosine kinase inhibitor, theerlotinib, also induced a progressive repigmentation of the hair of a patient suffering from metastatic lung adenocarcinoma three months after treatment. A case of hair repigmentation associated with erlotinib began after an episode of folliculitis on the scalp.
Finally, studies conducted on vitamins have shown that some of them have an effect on hair color. This is particularly evident in the repigmentation of prematurely gray hair in two healthy patients one month after starting a treatment with 200 mg per day of calcium pantothenate.
Another study conducted on 27 individuals with gray hair over a period of 8 months showed that the use of 100 mg of calcium pantothenate combined with 200 mg of PABA (4-aminobenzoic acid) per day allowed two individuals to observe a slight repigmentation of their hair. This study also noted that the repigmented hair returned to gray after discontinuing the treatment.
Important : the various treatments mentioned should never be undertaken without medical advice.
RAWNSLEY J. & al. Hair biology: Growth and pigmentation. Facial Plastic Surgery Clinics of North America (2018).
MESINKOVSKA N. & al. Medication-induced repigmentation of gray hair: A systematic review. Skin Appendage Disorders (2020).