Supplement analysis backed by scientific evidence · PT

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Limited evidenceJoints & skin

Birch Bark Extract (Betulin)

A triterpene extract whose only well-tested use is a topical gel for wound healing in the rare skin disease epidermolysis bullosa. As an oral supplement for skin or metabolism there is essentially no human evidence.

Evidence last reviewed: August 2026

What the science says

  • Topical gel for epidermolysis bullosa wounds Moderate evidence

    A phase III randomized trial (EASE) with 24-month follow-up tested a standardized birch triterpene gel (Oleogel-S10) on wounds in epidermolysis bullosa. Wound closure improved versus control gel, though the difference narrowed over long-term follow-up. This is a regulated topical medicine, not the oral extract sold as a supplement.

  • Oral betulin for metabolism or skin ageing Limited evidence

    Claims about betulin improving lipids, insulin sensitivity or skin ageing rest on cell and rodent work. A review of birch bark extract found no controlled human trials of oral use for these outcomes.

Dosage & safety

Studied doseNo established oral dose. The studied product is a topical gel containing about 10% birch triterpenes applied to wounds at each dressing change; oral capsules typically supply 100–500 mg of extract with no trial support.
SafetyThe topical gel commonly causes application-site pain and itching. Oral betulin has not been characterized for safety in humans; avoid in pregnancy, breastfeeding, and alongside medication without medical advice. Birch allergy is a plausible concern for sensitized people.

Scientific references

Where to buy

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