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Aluminum Chlorohydrate

Also known as: Aluminium chlorohydrate, ACH

A specific topical antiperspirant active; a 25% ingredient limit is not 25% elemental aluminum or a DIY formulation target.

Two-color collage of an unlabelled roll-on applicator beside a dish of pale powder
Editorial illustration

Aluminum chlorohydrate is an aluminum salt used to reduce underarm sweating. FDA's antiperspirant monograph lists it up to 25% on a specified anhydrous basis in compliant finished products. This is not 25% elemental aluminum, and evidence about topical exposure should not be replaced by assumptions from swallowed aluminum or other salts.1, 4

  • The monograph's 25% limit uses the ingredient's anhydrous basis, excluding specified diluents.1
  • U.S. labels warn against use on broken skin and advise asking a doctor before use with kidney disease.1
  • A small human tracer study measured absorption from a particular roll-on formulation, not lifetime cancer risk.2

What is Aluminum Chlorohydrate?

An antiperspirant reduces sweat; a deodorant claim alone concerns odor. These can coexist in one finished product. Aluminum chlorohydrate is separately listed from aluminum chloride and aluminum-zirconium complexes in FDA's monograph, so their names and allowed conditions are not interchangeable.1, 5, 4

Where it comes from

Natural sources

  • Aluminum is a naturally occurring element; the antiperspirant active is a manufactured salt

How it's made

Aluminum chlorohydrate is formulated for topical use. It is not metallic aluminum, aluminum chloride or a dietary mineral supplement.

What it does in products

  • Active ingredient in topical underarm antiperspirants

Benefits

Underarm sweat reduction in a compliant finished product

moderate evidence

The active has an established antiperspirant role, but the performance claim belongs to the tested finished formula, not an arbitrary raw-salt concentration.1

M019 sets ingredient, labeling and effectiveness-testing conditions. Small formulation changes can affect the result; listing an allowed active does not demonstrate that every product achieves the same sweat reduction.

Evidence scope and limitations

Topical aluminum chlorohydrate antiperspirants, FDA M019 and route-specific systemic safety evidence; not oral aluminum, aluminum chloride therapy or every aluminum-zirconium salt.

  • Monograph conditions apply to compliant finished products, not DIY mixtures.
  • Small tracer studies estimate absorption, not lifetime disease outcomes or inhalation safety.
  • Industry affiliations and a specific tested formula limit extrapolation of the absorption study.
  • Reassuring general risk assessments do not exclude local reactions or override kidney-disease labeling.

Evidence last checked: 2026-10-10

Side effects & safety

Local irritation or rash (varies)The monograph requires stopping use if rash or irritation occurs and excludes application to broken skin. Individual tolerance is not established by a low average absorption estimate.

Safety considerations

  • Topical absorption data cannot clear every medicine combination or be extrapolated to oral aluminum-containing products.
  • Not for: Ask a doctor before use if you have kidney disease, as the U.S. label requires.
  • Not for: Do not apply to broken skin; stop if irritation or rash occurs.
  • Not for: Follow route-specific aerosol warnings rather than treating roll-on absorption results as an inhalation assessment.
1, 2, 4

Amounts studied & product use

These figures describe research or common product use, not a personal dose or treatment recommendation.

In skincare studies and products

FDA M019 lists aluminum chlorohydrate up to 25% on an anhydrous basis, excluding buffer components, water and propellants. This is a condition for compliant commercial drug products, not a personal concentration recommendation or instruction to mix raw powder. Follow the finished product's underarm-use directions.

1

Regulatory status

  • In the United States, antiperspirants are OTC drugs. A product must meet the monograph's complete conditions and applicable drug requirements, not merely contain a listed active. Deodorant and antiperspirant claims have different intended-use classifications.
  • INCI name on cosmetic labels: Aluminum Chlorohydrate.
1, 5

Low absorption and cancer evidence are separate questions

The 2022 tracer study reported a very low absorbed fraction from its specified chlorohydrate roll-on. Its small healthy-volunteer sample and industry-affiliated authors limit generalization. A pharmacokinetic estimate does not directly test cancer outcomes.

NCI's fact sheet does not identify an established breast-cancer link from underarm antiperspirants. BfR's newer assessment considers adverse health effects from daily ACH antiperspirant use unlikely on current evidence. Neither statement means zero risk from every route, dose or formula, or removes the U.S. kidney-disease warning.

2, 3, 4, 1

Frequently asked questions

Is a 25% active label 25% elemental aluminum?

No. M019 specifies the anhydrous ingredient basis. Elemental aluminum, the active salt and the water-containing finished formula are different quantities.1

Does aluminum-free deodorant mean equivalent sweat reduction?

Not from the deodorant claim alone. FDA distinguishes odor-control cosmetics from antiperspirant drugs. A product's actual claim and evidence matter more than the absence of this one ingredient.5, 1

The bottom line

Read the specific active, concentration basis and finished-product directions; keep sweat efficacy, local tolerance and systemic safety as separate questions.

References

  1. OTC Monograph M019: Antiperspirant Drug Products for OTC Human Use. U.S. Food and Drug Administration (2021) · government guidance · Final administrative order OTC000015; M019; posted November 23, 2021
  2. de Ligt R, Westerhout J, Grossouw D, Buters TP, Rissmann R, Burggraaf J, Windhorst AD, Tozer S, Pappa G, Wall B, Bury D, Mason DR, Vaes WHJ. Assessment of dermal absorption of aluminium from a representative antiperspirant formulation using a (26Al)Al microtracer approach: a follow-up study in humans. Toxicology Research (2022) · primary study · PMID 35782644; DOI 10.1093/toxres/tfac029; pharmacokinetic study, not a cancer trial
  3. Antiperspirants/Deodorants and Breast Cancer. National Cancer Institute (2016) · government guidance · Reviewed August 9, 2016
  4. Aluminium in antiperspirants: Health impairments unlikely according to current knowledge. German Federal Institute for Risk Assessment (BfR) (2025) · government guidance · FAQ dated November 25, 2025; describes 2020 and 2023 reassessments
  5. Is It a Cosmetic, a Drug, or Both? (Or Is It Soap?). U.S. Food and Drug Administration · government guidance · Accessed October 10, 2026; classification depends on intended use

Revision history

  1. Initial AI-assisted source checks and claim-level citation mapping under the site-authorized publishing workflow. No separate human or independent medical review is claimed.