Aluminum Zirconium Tetrachlorohydrex Gly
Aluminum Zirconium · AZT Gly
What it is
A water-soluble aluminum-zirconium salt complex (CAS listed under Annex III, position 50 of EU Cosmetics Regulation 1223/2009). Forms a gel plug in eccrine sweat-gland ducts on the outer epidermis to reduce sweat reaching the skin surface.
In this product: Active antiperspirant agent.
Dose & route, what actually matters
Dermal, topical application to underarm skin. Shaved or depilated skin was specifically studied by SCCS for higher theoretical penetration; systemic aluminum from cosmetics was still found safe.
EUROPEAN UNION
Restricted under Annex III of EU Cosmetics Regulation 1223/2009, position 50. Permitted up to 6.25% as Al in non-spray formats and 10.60% as Al in spray formats, a precautionary concentration cap, not a danger finding.
UNITED STATES
Permitted as a Category I active ingredient under the FDA OTC Antiperspirant Drug Products monograph (21 CFR Part 350). No aluminum-weight-based concentration cap equivalent to the EU limit.
The evidence
SCCS/1613/19 (2019/2022): 'Only a very small proportion of aluminum from dermally applied cosmetic products can penetrate the skin ... there are no reliable indications of a causal association between aluminium exposure and breast cancer; there are no reliable indications of a causal association between aluminium exposure and neurodegenerative diseases.'
regulatory · 2022 · source
BfR (2020): 'Aluminium in antiperspirants: low contribution to the total intake of aluminium in humans.'
regulatory · 2020 · source
California Prop 65: Not listed.
How to avoid it
Switch to a deodorant (no sweat reduction) rather than an antiperspirant. Aluminum salt complexes only appear as the active ingredient, they are listed first and clearly.
Where it hides
Editorial analysis of publicly available regulatory and peer-reviewed sources. Not medical advice. We name our evidence and link it, including when an ingredient is fine.