CA inhibitor 1 treatment has only transient effects on estrous cyclicity in mice

Approximately 45% of new HIV infections worldwide occur in women and girls and adherence to pre-exposure prophylaxis (PrEP) to prevent HIV infection is limited. Long-acting PrEP such as lenacapavir may improve adherence. One barrier to PrEP usage in women and girls is impact on the menstrual cycle, though impacts of long-acting PrEP are unclear. To model the effect of lenacapavir administration on cyclicity, adult female C57Bl/6J mice were injected with CA inhibitor 1 and assessed for estrous cyclicity. Ca inhibitor 1 transiently delayed the start of the next cycle. However, Ca inhibitor 1 was associated with a higher proportion of normal length estrous cycles. Ca inhibitor 1 did not impact astrocyte immunoreactivity or chronic cellular activity in the medial preoptic area (mPOA), a major regulator of the estrous cycle. These findings suggest that lenacapavir may be a viable PrEP alternative for those concerned with PrEP impacts on menstrual cycle.