NuvaRing Progestin Dosage
The NuvaRing releases 120 μg of etonogestrel (the active progestin) per day. 1, 2
Detailed Composition and Release Information
NuvaRing is a combined hormonal contraceptive vaginal ring that contains:
- Total content: 11.7 mg etonogestrel and 2.7 mg ethinyl estradiol 2
- Daily release: 120 μg etonogestrel and 15 μg ethinyl estradiol 1, 2
Mechanism and Delivery
The ring works through continuous, controlled release of hormones through the vaginal epithelium. This delivery method:
- Avoids daily fluctuations in serum hormone levels typically seen with oral contraceptives 3
- Bypasses gastrointestinal absorption and first-pass hepatic metabolism 4
- Provides steady, uniform blood concentration of hormones 4
Clinical Considerations
The NuvaRing is designed for a single 3-week use followed by a 1-week ring-free period 3. This regimen:
- Provides robust ovulation inhibition 3
- Has a typical-use failure rate of approximately 9% 1
- May have better compliance than daily oral contraceptives due to once-monthly administration 4
Important Usage Notes
- The ring should remain in place for 3 weeks (21 days)
- A new ring should be inserted after the 7-day ring-free interval even if bleeding has not stopped 1
- The ring can be removed for up to 3 hours during intercourse if desired, though this is not typically recommended 1
Pharmacokinetic Profile
Compared to combined oral contraceptives containing 30 μg ethinyl estradiol:
- Maximum serum concentrations of etonogestrel from NuvaRing are approximately 40% of those from oral contraceptives 5
- After insertion, maximum serum concentrations are achieved in approximately 1 week 5
- The absolute bioavailability of etonogestrel from NuvaRing is higher than from oral contraceptives (102.9% vs. 79.2%) 5
Safety Considerations
Like other combined hormonal contraceptives, NuvaRing:
- Has the same contraindications as combined oral contraceptives 3
- Carries a risk of venous thromboembolism, including cerebral venous sinus thrombosis 6
- Should not be used during the first 3 weeks postpartum due to increased risk of venous thromboembolism 1
The NuvaRing's progestin component (etonogestrel 120 μg daily) is the active metabolite of desogestrel and provides effective contraception while maintaining a favorable side effect profile for most users.