Don’t take our word for it. Here’s every fact on this site, with its evidence grade, its caveats, and a link to the source, so you can check us.
We start you on the strong ones: findings that have been replicated or come from one large, well-controlled study. Moderate and weak facts are here too, labeled for what they are. Use “Link to this fact” to share a single card.
Health effects / Animal study
AETT, a musk fragrance once common in soaps, deodorants, and cosmetics, caused progressive nerve-fiber demyelination and irreversible pigment build-up in the brains of rats fed the compound for 12-20 weeks; the fragrance industry voluntarily withdrew it from cosmetics in 1978 on the strength of its own data.
Moderate evidence: Small single-lab study (N=16 rats), one route (dietary), one dose pair (25/50 mg/kg/day); AETT was withdrawn from cosmetics in 1978 and is not a current fragrance ingredient.
Source: Spencer 1979, Science Industry-funded Link to this fact
Health effects / Lab study (cells or chemistry)
Among 62 individually tested deodorant ingredients, only fragrance chemicals (plus one insect-pheromone contaminant) showed any estrogenic activity; no carrier, stabilizer, emulsifier, plasticizer, antitranspirant, or other active ingredient (including triclosan and BHT) tested positive.
Moderate evidence: Only 62 of the many ingredients found by GC/MS screening were selected for individual testing, based on frequency of occurrence; ingredients not selected were not tested at all.
Health effects / Measured in people or real products
A Korean government risk assessment of 64 deodorants found that at the maximum concentrations actually measured in the products, none of the 19 fragrance and biocidal ingredients carried to detailed (tiered 2) assessment exceeded its margin-of-exposure or hazard-quotient safety threshold, for either the inhalation or the dermal route.
Moderate evidence.
Caveats
A single government risk-assessment study using modeled Korean population-average exposure factors and mostly-animal (rat) toxicity reference values with standard uncertainty factors, not a clinical safety trial; not independently replicated.
Source: Kim et al. 2018, Science of The Total Environment Link to this fact
Health effects / Other evidence
The more types of personal care product a man had used in the previous 48 hours (cologne, aftershave, hair gel, deodorant, lotion), the higher his urinary MEP, rising about 33% per additional product type.
Moderate evidence: Five product categories; very few men used four or five types (22 and 3); no health outcome measured.
Source: Duty 2005, Environmental Health Perspectives Link to this fact
Information, not medical advice. See also: myths we won’t tell you.