The combined contraceptive vaginal ring, NuvaRing, and tampon co-usage.

We investigated the effect of tampon co-usage on systemic exposure to etonogestrel (ENG) and ethinylestradiol (EE) from the combined contraceptive vaginal ring, NuvaRing. One cycle of ring use consists of 3 weeks of ring use followed by a 1-week ring-free period. Fourteen healthy women were randomized to use both NuvaRing and tampons (Kotex( regular) or NuvaRing alone for one cycle; participants then switched to the alternate treatment regimen for a second cycle of ring use. The first tampon was self-administered on day 8 of the interaction cycle; 4 tampons a day were used for 3 consecutive days. Tampon co-usage did not result in any changes in serum ENG or EE concentrations and is thus not expected to compromise the ring's contraceptive efficacy.