Homosalate, a common sunscreen ingredient, showed concerning effects on hormone balance in male fish—it lowered testosterone levels, increased estrogen, and caused liver damage. When combined with avobenzone (another sunscreen UV filter), these hormone-disrupting effects got worse. The researchers emphasized that we need more studies on what happens with long-term sunscreen use.

Scientists exposed male zebrafish and human hormone-producing cells to homosalate alone and mixed with avobenzone, then measured changes in testosterone, estrogen, gene activity, and liver health.

Funding not disclosed in abstract