GradedHealth

Can grey hair be reversed? What the evidence shows about remedies

A 2025 review found no product that reliably restores grey-hair colour. One small trial hints at prevention, and treating a deficiency helps some people.

Published October 2026

Short answer

The evidence is limited: nothing reliably reverses grey hair. The best-supported steps are a doctor conversation about B12, iron, folate and thyroid tests and not smoking; dyes cover the rest but can cause allergy. Evidence grade C (Limited). One small randomised trial plus case reports, case-control and cross-sectional studies; downgraded for small samples, mixed results and no controlled trial of visible colour change.

Key takeaways

  • A 2025 review of grey-hair research concluded no treatment provides a lasting solution and consistently effective options remain limited [1].
  • In a 24-week randomised trial of 44 women, a Pueraria lobata extract lotion led to fewer new grey hairs than placebo (6.3 vs 11.4 per cm2), but neither doctors nor volunteers saw a visible change [2].
  • Case-control studies link premature greying to lower vitamin B12, folate or ferritin and to thyroid problems, and a 2020 systematic review reports colour returning in some cases once those are treated [3][4][5][6].
  • Among 6,390 young men, family history was associated with about 13-fold higher odds of early greying, obesity with about 2.6-fold and smoking more than 5 pack-years with about 1.6-fold [7].
  • Anti-grey supplements are unproven, and He Shou Wu (Polygonum multiflorum), a common ingredient in such products, has been linked to liver injury [8].

What the study did

A 2025 review in Clinical, Cosmetic and Investigational Dermatology examined why hair turns grey and pulled together the evidence on preventing and treating it, covering genetics, diet, supplements, topical treatments, laser therapy and hair dye [1]. It is a narrative review - one author's reading of the literature rather than a systematic search - so it maps what has been studied without grading the quality of each study [1].

What it found

The review's central conclusion is that no current treatment provides a permanent solution for grey hair, and consistently effective options remain limited [1]. It describes greying as mainly a natural, largely genetic part of ageing rather than a disease [1]. It lists the options people try - antioxidant-rich diets, B vitamins, topical melanin stimulants and low-level laser therapy - but says these need more research before they can be called effective [1]. For people with early greying and no family history, it recommends blood tests for vitamin B12, folic acid and thyroid function, because treating those problems can restore colour in some cases [1].

How it fits

Other reviews agree that evidence-based treatments are lacking [9][10]. The best-controlled test of a remedy is a single small randomised trial: 44 women applied a lotion with Pueraria lobata extract (APHG-1001) or a placebo twice daily for 24 weeks [2]. The treated group grew fewer new grey hairs (6.3 vs 11.4 per cm2), but dermatologist and volunteer assessments found no visible difference in overall greyness [2]. A 3-month study in 15 men of a cosmetic alpha-MSH peptide lotion (10 ppm) reported changes in melanin-related proteins in plucked hairs [11], and a single case report describes a 25-year-old woman whose grey hair turned black after five months of a similar peptide lotion plus supplements [12].

Greying is not always permanent: mapping pigment along individual hairs from 14 volunteers showed some grey hairs regain colour, a rare event that in that study tracked periods of reported stress and relief [13]. A systematic review of 27 reports found grey hair darkening with medications such as psoralens and B-vitamin supplements, but called the evidence low-quality and stressed these drugs are not approved for greying [14]. The newest report, an uncontrolled series, found hair darkened by at least half in 60% of 10 patients given exosome injections [15].

Blood-test studies suggest a treatable minority. A case-control study of 52 patients under 20 found lower vitamin B12, folate and biotin than in controls [4]. A series of 71 patients found vitamin B12 deficiency and hypothyroidism significantly associated with early greying, though ferritin was not [3], while a 300-versus-300 study found low ferritin in 14.7% of cases versus 2.7% of controls and no vitamin D difference [5]. A 2020 systematic review and meta-analysis concluded that treating accompanying conditions led to reversal 'in many cases', and gave only a low-grade (2A) recommendation to calcium pantothenate and PABA [6].

Large surveys consistently flag family history, smoking and obesity: among 6,390 men under 30, family history of early greying carried the highest odds (about 13 times), followed by obesity (2.6) and more than five pack-years of smoking (1.6) [7]. A review of 32 studies found premature greying more common in smokers [16], and in 2,644 students and doctors, obesity, combined B12 and vitamin D deficiency, family history, lack of exercise and smoking went with earlier greying, while higher stress went with earlier onset [17]. Not every study agrees - a 600-person case-control study found no smoking or vitamin D link [5].

Covering grey hair with dye works immediately, but hair dyes commonly cause contact allergy: allergy to p-phenylenediamine, the main allergen, affects an estimated 0.1-2.3% of the general population [18], and 'black henna' mixtures that add it sensitised about 2.5% of users in one review [19]. Pure henna allergy is uncommon but documented [20]. Supplements sold for greying carry their own risks: He Shou Wu (Polygonum multiflorum) has been tied to liver-injury reports in several countries [8], and biotin can distort some laboratory tests [21]. A 2026 expert panel on hair ageing agreed that minoxidil is the only medicine with enough support for age-related hair changes in general, and said treatments for pigment loss need more research [22].

Limits

The 2025 review is a narrative review, not a systematic one, so its list of treatments is neither exhaustive nor quality-graded [1]. The one randomised trial was small (44 women), short (24 weeks), and its positive result was a count of new grey hairs rather than a change anyone could see [2]. Most recovery stories are single cases or uncontrolled series, which cannot show that the treatment, rather than chance, caused the change [12][15]. The risk-factor studies are surveys that rely on people's memories and cannot prove cause and effect [7][5]. And cosmetic studies often measure cells or proteins in plucked hairs rather than how hair looks [11].

Go deeper

  • Grey Hair — Premature greying is common, usually inherited, and linked to smoking and to some treatable deficiencies.

References

  1. Gray Hair: From Preventive to Treatment.. Clin Cosmet Investig Dermatol, 2025.
  2. Efficacy and Safety of Pueraria lobata Extract in Gray Hair Prevention: A Randomized, Double-Blind, Placebo-Controlled Study.. Ann Dermatol, 2013.
  3. Demographic Characteristics and Association of Serum Vitamin B12, Ferritin and Thyroid Function with Premature Canities in Indian Patients from an Urban Skin Clinic of North India: A Retrospective Analysis of 71 Cases.. Indian J Dermatol, 2017.
  4. Prospective Analytical Controlled Study Evaluating Serum Biotin, Vitamin B12, and Folic Acid in Patients with Premature Canities.. Int J Trichology, 2017.
  5. Epidemiological and biochemical factors (serum ferritin and vitamin D) associated with premature hair graying in Egyptian population.. J Cosmet Dermatol, 2021.
  6. Premature graying of hair: Risk factors, co-morbid conditions, pharmacotherapy and reversal-A systematic review and meta-analysis.. Dermatol Ther, 2020.
  7. Association of premature hair graying with family history, smoking, and obesity: a cross-sectional study.. J Am Acad Dermatol, 2015.
  8. Polygonum multiflorum: Recent updates on newly isolated compounds, potential hepatotoxic compounds and their mechanisms.. J Ethnopharmacol, 2021.
  9. Premature Graying of Hair: A Comprehensive Review and Recent Insights.. Indian Dermatol Online J, 2024.
  10. Hair Graying Update and Review.. Actas Dermosifiliogr, 2026.
  11. Efficacy of an agonist of α-MSH, the palmitoyl tetrapeptide-20, in hair pigmentation.. Int J Cosmet Sci, 2018.
  12. Reversal of Premature Hair Graying Treated with a Topical Formulation Containing α-Melanocyte-Stimulating Hormone Agonist (Greyverse Solution 2%).. Int J Trichology, 2022.
  13. Quantitative mapping of human hair greying and reversal in relation to life stress.. Elife, 2021.
  14. Medication-Induced Repigmentation of Gray Hair: A Systematic Review.. Skin Appendage Disord, 2020.
  15. Hair Repigmentation Outcomes in Patients With Graying Hair Treated With Exosome Therapy: A Cross-Sectional Observational Study.. J Cosmet Dermatol, 2025.
  16. The Effects of Smoking on Hair Health: A Systematic Review.. Skin Appendage Disord, 2021.
  17. Premature Hair Graying and Its Associated Factors Among Medical Students and Resident Physicians at Imam Abdulrahman Bin Faisal University.. Healthcare (Basel), 2025.
  18. Dermatological adverse effects of hair dye use: A narrative review.. Indian J Dermatol Venereol Leprol, 2023.
  19. Side-effects of henna and semi-permanent 'black henna' tattoos: a full review.. Contact Dermatitis, 2013.
  20. Allergic Contact Dermatitis to Pure Henna: A Systematic Review.. Contact Dermatitis, 2026.
  21. Biotin Supplementation-The Cause of Hypersensitivity and Significant Interference in Allergy Diagnostics.. Nutrients, 2025.
  22. Hair Aging Revisited: An Expert Delphi Consensus on Pathogenesis, Clinical Features, and Future Therapies.. Dermatol Ther (Heidelb), 2026.