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.
Hidden ingredients / Journalism
Laboratory testing commissioned by US campaigners found 38 chemicals not listed on the label across 17 popular fragrances, 14 per product on average, including hormone-disrupting synthetic musks.
Moderate evidence: NGO report, not peer reviewed; numbers now verified against the primary (Sarantis 2010, in our evidence base); one sample per product, tentative library IDs, no concentrations.
Source: Sealey 2016 (citing Sarantis 2010, Not So Sexy), Environment International Link to this fact
Hidden ingredients / Measured in people or real products
Once in the air, scent chemicals such as linalool, ionones, and the woody musk OTNE ('Iso E Super') reacted with ozone to form dozens of new oxidized chemicals, including a hydroperoxide. None of these was in the product.
Moderate evidence: Compound identities are tentative (formula-level mass spectrometry); products unquantified; no hazard testing.
Source: Wu 2024, Environmental Science & Technology Letters Link to this fact
Hidden ingredients / Review of other studies
Fragrance in deodorants and antiperspirants often functions as a deliberate odor-masking ingredient at percent-level concentrations (e.g., linalool combined with dihydromyrcenol at 0.2-1% w/w, or a multi-fragrance blend of musk, skatole, lemon oil, lavender oil, jasmine, vanillin, benzoin, benzyl acetate, and menthol in one patented licorice-root deodorant), separate from and in addition to any anti-microbial active in the same product.
Moderate evidence.
Caveats
Review compiling cosmetics-industry patents and older formulation studies, not new experimental data; the specific listed formulations are patent examples, not necessarily current marketed products.
Source: Kanlayavattanakul & Lourith 2011, International Journal of Cosmetic Science Link to this fact
Hidden ingredients / Lab study (cells or chemistry)
Testing 62 individually purchased fragrance-related ingredients found in the deodorants, 8 were estrogenic in the same cell assay – including the musk HHCB/galaxolide and benzyl salicylate – at potencies the study describes as comparable to parabens, a preservative class with well-documented weak estrogenic activity.
Moderate evidence.
Caveats
Potencies were 100,000 to 100,000,000 times weaker than estradiol (EC50 3.08×10^-6 to 1.45×10^-4 M; EEF 2.34×10^-8 to 1.15×10^-6); a positive result in this cell assay does not establish that any dose reaches human tissue.
Hidden ingredients / Other evidence
Several flavor chemicals in this review (menthol, carvone, camphor, borneol, terpineol, ionones, damascones and the musks muscone, and civettone) are also fragrance materials, but the FEMA review assesses them only as swallowed food ingredients; it gives non-oral data 'less weight' and has no inhalation or skin-allergy assessment.
Moderate evidence: The paper says some inhalation data may substitute when flavor exposure is far smaller than inhaled exposure; it does not claim any airborne or skin risk from these substances.
Source: Adams 1996, Food and Chemical Toxicology Industry-funded Link to this fact
Hidden ingredients / Other evidence
FEMA has removed at least 14 substances from its GRAS list over the years, including musk ambrette, quinoline, calamus, ethylene oxide, and methyl eugenol; the most common reason was that existing data no longer supported a conclusion of general recognition of safety, not newly shown harm.
Moderate evidence: List and reasons are FEMA's; the paper does not date each removal or give the data behind it. The count of 14 treats calamus and calamus oil as one.
Source: Hallagan 2020, Food and Chemical Toxicology Industry-funded Link to this fact
Hidden ingredients / Measured in people or real products
The lab was Analytical Sciences in Petaluma, California, using modified US EPA methods 8260 and 8270 (GC/MS) plus a separate GC/MS method for six synthetic musks.
Moderate evidence: Method description is brief; no QC data or confirmation status for each compound is given.
Source: Sarantis et al. 2010 (Not So Sexy, Canadian edition) Link to this fact
Hidden ingredients / Measured in people or real products
All 17 tested perfumes, colognes, and body sprays contained at least one synthetic musk; Galaxolide was in 15 and was not on any of those 15 labels.
Moderate evidence: Qualitative detection; musk concentrations are not reported; one sample per product.
Source: Sarantis et al. 2010 (Not So Sexy, Canadian edition) Link to this fact
Hidden ingredients / Lab study (cells or chemistry)
In lab tests on human cells, four fragrance musks (including Galaxolide and Tonalide) blocked the progesterone receptor; Tonalide (AHTN) and Phantolide (AHMI) did so at about 0.02 µM, the strongest effect in the study, and Galaxolide (HHCB) at 0.2 µM.
Moderate evidence.
Caveats
Cell-reporter assay, single compounds, one lab, test-tube concentrations; no animal or human data and no comparison with body levels. Two authors work at the company that sells the assay.
Source: Schreurs 2005, Toxicological Sciences Link to this fact
Hidden ingredients / Other evidence
In a 2005 lab study on mussel gill tissue, six synthetic musks used as fragrance ingredients, including musk xylene, musk ketone, galaxolide and tonalide, blocked the cell's pump that expels foreign chemicals, at micromolar concentrations.
Moderate evidence.
Caveats
Ex-vivo marine mussel gill, one lab, n=3-7 animals per compound, one dye assay; no human cells or exposures; effective concentrations exceed measured water levels and the authors' estimate of human body burdens.
Source: Luckenbach 2005, Environmental Health Perspectives Link to this fact
Hidden ingredients / Other evidence
The 'white musk' scent oil tested in a 2025 Japanese lab study was a blend of synthetic fragrance ingredients: its largest peak was linalool (11.9% of GC peak area), then hedione (8.3%), galaxolide (5.2%), hexyl cinnamal (4.6%), benzyl acetate (3.7%) and tonalide (1.6%), with galaxolide at 34.8 mg/mL and tonalide at 15.0 mg/mL in the neat oil.
Moderate evidence: One product from the study's own co-developer, one analysis; percentages are peak areas, not weight; other peaks were not identified; other 'white musk' products may differ.
Source: Zennifa 2025, Scientific Reports Industry-funded Link to this fact
Information, not medical advice. See also: myths we won’t tell you.