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Other Ingredients

Homosalate

Also known as: Homomenthyl salicylate, HMS, 3,3,5-Trimethylcyclohexyl salicylate

The sunscreen solvent that also filters — ubiquitous at high concentrations, with an EU limit and absorption scrutiny.

  • By IngredientWiki Editorial Team
  • Fact-checked by IngredientWiki Editorial Team
  • Updated 2026-09-26
  • 2 min read

In short

Homosalate is an organic UVB filter with an unusual dual identity: it is also an excellent solvent for other crystalline sunscreen actives, which is why American sunscreens use it at higher concentrations than almost any other filter — up to 15% in the US. Its absorption profile caught regulators' attention in the FDA's 2020 studies, showing systemic levels above the agency's threshold of concern, and the EU has limited it to 0.5% in face products and 7.34% overall (2025), while the US continues to permit 15%. It is well tolerated, and like the other scrutinized US filters, its question marks concern data gaps and conservative thresholds rather than demonstrated harm.

  • UVB filter + solvent for other actives (dual role)
  • US allows up to 15% — among the highest of any filter
  • FDA 2020: systemic absorption above threshold of concern
  • EU limits 7.34% overall (0.5% face products) from 2025

What is Homosalate?

Homosalate is the sunscreen ingredient that quietly holds American formulas together — literally. It filters UVB, but formulators value it equally as a solvent that dissolves other crystalline actives, which is why US products use it at up to 15%, higher than nearly any other filter. That high usage is exactly what pulled it into the FDA's 2020 absorption spotlight, producing the now-familiar pattern: blood levels above a deliberately conservative threshold, no demonstrated harm, and a regulatory split — the EU capping concentrations, the US keeping them. Homosalate is best understood as the case that sharpened the whole organic-filter debate.

Where it comes from

Natural sources

  • Fully synthetic salicylate ester, used in sunscreens since the 1970s

How it's made

Oily liquid at up to 15% in US sunscreens; EU limit 7.34% overall from 2025.

What it does in products

  • UVB absorption
  • Solvent for crystalline UV actives
  • SPF-system compatibility
  • Water-resistance support

Benefits

UVB protection

strong evidence

Provides reliable sunburn protection as part of combination systems — the foundational public-health function of sunscreens.

Formula compatibility

strong evidence

Its solvent role lets otherwise-insoluble filters combine in high-SPF products — the formulation chemistry behind American SPF 50+ formulas.

Good tolerability

strong evidence

Low irritation and sensitization rates across decades of widespread use.

Side effects & safety

Contact allergy (rare)Uncommon.

Safety considerations

  • No specific restriction; the FDA absorption findings prompt some clinicians to suggest mineral alternatives in pregnancy as a precaution.
  • None significant.
  • Not for: Known allergy

How it's used

In supplements

Not an oral ingredient.

In skincare

Up to 15% in US sunscreens (EU: 7.34% overall limit from 2025).

Regulatory status

  • FDA-approved OTC sunscreen active (up to 15%); included in the agency's GRASE re-review.
  • INCI name on cosmetic labels: Homosalate.
  • Regulated as OTC drug active.

Popular products containing Homosalate

  • Banana Boat / Coppertone sport sprays — High-SPF systems with homosalateVarious · OTC drug
  • Neutrogena Beach Defense (US) — High-concentration UV systemsNeutrogena · OTC drug
  • Australian Gold (US formulas) — Homosalate-anchored SPF linesAustralian Gold · OTC drug

Product names and brands are shown for reference and belong to their respective owners.

The solvent-filter double life

Most UV filters are crystalline powders needing dissolution; homosalate is an oily liquid that both absorbs UVB and dissolves its powder colleagues. That double duty is why high-SPF American formulas lean on it at 10–15% — a usage level that in turn explains why the FDA's absorption study flagged it.

The regulatory split

The FDA's 2020 maximal-use study measured homosalate in blood above the agency's threshold of toxicological concern, prompting a GRASE re-review. The EU moved to precautionary concentration limits (7.34% overall from 2025), while the US has maintained 15% pending further data. The same molecule, two regulatory philosophies.

Frequently asked questions

Why is homosalate in sunscreen at such high percentages?

It doubles as a solvent for other filters — higher concentrations support high-SPF systems that would otherwise be impossible to formulate.

Is homosalate an endocrine disruptor?

It shows weak hormonal activity in some assays, but human endocrine effects from sunscreen use have not been established — the same signal-versus-outcome gap as related filters.

Should I avoid homosalate?

Current evidence still favors wearing sunscreen. If you prefer lower-absorption options, mineral (zinc/titanium) or EU-limit-compliant formulas are available.

The bottom line

Homosalate is a functional, well-tolerated UVB filter whose high US concentrations put it at the center of the organic-filter absorption debate — with the evidence still favoring sun protection.

References

  1. FDA sunscreen absorption study. JAMA. https://pubmed.ncbi.nlm.nih.gov/31058986/
  2. Homosalate: safety evaluation. PubMed Central. https://pubmed.ncbi.nlm.nih.gov/31778460/
  3. EU homosalate concentration limits. European Commission. https://ec.europa.eu/growth/sectors/cosmetics/legislation_en