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Limited evidenceLongevity & antioxidants

Catalase

An enzyme sold on the theory that hair goes grey because hydrogen peroxide builds up in the follicle. The mechanism has some support; swallowing catalase to reverse grey hair has none.

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What the science says

  • Reversing grey hair Limited evidence

    The rationale comes from work showing that hair follicles accumulate hydrogen peroxide with age and lose catalase activity, which bleaches hair from within. That finding is about enzyme activity inside the follicle; no trial has shown an oral catalase supplement reaches follicles or changes hair colour.

  • Antioxidant supplementation for hair Limited evidence

    A review of oxidative stress in age-related greying describes multiple contributing pathways and notes that topical or systemic antioxidant interventions have not been demonstrated to restore pigment. Orally administered catalase is a protein and is digested into amino acids like any other.

Dosage & safety

Studied doseNo dose has any efficacy evidence. Products typically list 5,000–10,000 IU of catalase, often combined with saw palmetto, biotin or copper.
SafetyNo serious risks reported at label doses, largely because the enzyme is digested. Some products are derived from bovine liver or Aspergillus, which matters for allergies and dietary restrictions. Do not use it to delay evaluation of sudden or patchy hair colour or hair loss changes, which can have medical causes.

How to take it

TimingTiming does not matter.
With food?With or without food; the enzyme is digested either way.
Worth knowingMost catalase products are blends with biotin, copper or saw palmetto, so check you are not doubling those up from another supplement.

Frequently asked questions

Does catalase reverse grey hair?

No trial shows it does: the theory is that hydrogen peroxide builds up in ageing hair follicles as their own catalase activity falls, but no study shows a catalase supplement reaches the follicle or changes hair colour. The evidence is limited to the mechanism.

Can a swallowed catalase supplement reach hair follicles?

Oral catalase is a protein, so it is digested into amino acids like any other protein. Reviews of age-related greying note that antioxidant treatments have not been shown to restore hair pigment.

How much catalase should I take for grey hair?

No catalase dose has any efficacy evidence; products typically list 5,000–10,000 IU, often combined with saw palmetto, biotin or copper. Check you are not doubling up those ingredients from another supplement.

Is catalase safe to take?

Catalase supplements have no serious reported risks at label doses, largely because the enzyme is digested. Some are made from bovine liver or Aspergillus, which matters for allergies and diets, and sudden or patchy changes in hair colour should be checked by a doctor.

Scientific references

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