Letter to the Editor on “Associations between urinary biomarkers of phthalates and phthalate alternatives and female sexual function in a North American cohort”

Schildroth and colleagues address an underexplored area by examining how everyday chemical exposures may relate to women’s sexual well-being. Phthalates are synthetic chemicals used as plasticizers, widely present in personal care products, plastics, food packaging, and household items, including di-n-butyl phthalate (DnBP), di(2-ethylhexyl) phthalate (DEHP), and alternatives such as mono-carboxyisononyl phthalate (MCNP). Their potential to affect hormonal and reproductive pathways has raised concern, yet we still know relatively little about how these exposures relate to sexual function, especially among women trying to conceive. By collecting multiple urine samples and pairing them with validated sexual function measures, this study fills an important gap.1 The results present a complex and somewhat inconsistent pattern that merits careful consideration. The authors analyzed data from 347 preconception women who provided pooled urine samples shortly after enrollment and completed sexual function questionnaires about a month later. Most phthalate and phthalate-alternative metabolites were only weakly associated with sexual function, yet several showed clearer patterns. DnBP-related metabolites—especially mono-n-butyl phthalate—were linked to slightly lower scores, particularly in orgasm and pain. In contrast, MCNP and certain DEHP metabolites showed small but more positive associations, including higher desire, better arousal, greater satisfaction, and reduced discomfort. Several relationships were non-linear, and vaginal lubricant use appeared to modify some associations. Overall, the findings suggest that phthalates may influence sexual function differently depending on the compound and individual behaviors.1