Encyclopedia · supplement
Catalase and pseudocatalase
The idea that hair grays because follicles accumulate hydrogen peroxide has a real basis in vitiligo skin, but catalase supplements for gray hair have no human trial evidence.
What it is
Catalase is the enzyme that breaks hydrogen peroxide into water and oxygen. Pseudocatalase is a manganese-based mimic used in a UV-activated vitiligo cream. Catalase-containing supplements and "anti-gray" shampoos are marketed.
How it works
Reviews list cumulative oxidative damage as one contributor to graying among several. Paus 2024 In segmental vitiligo, skin showed low catalase and hydrogen peroxide build-up, and a pseudocatalase cream plus narrowband UVB repigmented skin and eyelashes in 5 patients. That is vitiligo, an autoimmune pigment loss, not ordinary age-related graying. Schallreuter 2013
What the studies show
- The vitiligo study measured 10 patients and treated 5, with no control group, and came from the group that developed the product. Schallreuter 2013
- No trial of oral catalase for common gray hair was found (PubMed search 2026-10-10).
How it's used in studies
Topical pseudocatalase with narrowband UVB phototherapy in vitiligo studies. There is no graying dose.
Side effects and safety
Phototherapy has its own skin-cancer considerations. Oral enzymes are normally digested, so a pill may add little catalase activity at the follicle.
Bottom line
A plausible story with no trial for gray hair. See gray hair.
Fun facts
- Vitiligo research reported eyelashes regaining colour after a peroxide-clearing cream plus UV light, in 5 people. Schallreuter 2013
Studies 2
Schallreuter KU et al. Basic evidence for epidermal H2O2/ONOO(-)-mediated oxidation/nitration in segmental vitiligo is supported by repigmentation of skin and eyelashes after reduction of epidermal H2O2 with topical NB-UVB-activated pseudocatalase PC-KUS. FASEB J. 2013
Tested: topical pseudocatalase plus narrowband UVB
Result: Low catalase and peroxide build-up in vitiligo skin; skin and eyelashes repigmented in 5 patients; no control group.
Read the study ↗Paus R, Sevilla A, Grichnik JM. Human hair graying revisited: principles, misconceptions, and key research frontiers. J Invest Dermatol. 2024
Result: Graying reflects oxidative and DNA damage, mTORC1 signalling and pigment-cell ageing; it becomes irreversible only once bulge pigment stem cells are depleted.
Read the study ↗Related
- Gray hair and premature grayingGraying is mostly genetic, but single-hair mapping shows some gray hairs can regain colour, and the famous stress-causes-gray mechanism has only been proven in mice.
- LuteolinA plant flavonoid sold as a supplement slowed hair graying in a mouse model while two similar antioxidants did not, and there is no human data at all.
- Para-aminobenzoic acid (PABA)A 1950 physician report described gray hair darkening on high-dose PABA, and the idea has survived 75 years on weak evidence.