Does nexplanon have less mcg per day of progestin than nuvaring? do nexplanon serum levels stay consistent regardless of decreasing amounts per year?

Yes & No: Nexplanon releases less etonorgestrel on a daily basis than Nuvaring. Serum concentrations of etonorgestrel decrease by about 50% towards then end of the third year of use. However, Nexplanon maintains its effectiveness throughout this 3 year period and is probably overall the most effective reversible contraceptive out there (other than total abstinence) as long as it's replaced every 3 years.

See Answer: NuvaRing is a polymeric vaginal ring containing 11.7 mg etonogestrel and 2.7 mg ethinyl estradiol, which releases on average 0.12 mg/day of etonogestrel and 0.015 mg/day of ethinyl estradiol. NEXPLANON contains 68 mg etonogestrel. the mean (± SD) maximum serum etonogestrel concentrations were 1200 (± 604) pg/mL ag 2 weeks. Levels decline so it has to be replaced.