Halpern V, Brache V, Taylor BSD, et al. - Researchers conducted this partially randomized, multicenter, parallel-group study with the aim to determine the pharmacokinetics and pharmacodynamics of medroxyprogesterone acetate after a single subcutaneous injection in the abdomen of 150 or 300 mg Depo-Provera. In addition, they compared the results to two injections of Depo-SubQ Provera 104 given 3 months apart. A single subcutaneous injection of 150 mg (n = 24) or 300 mg (n = 9) of Depo-Provera or two injections of Depo-SubQ Provera 104 (n = 9) was administered to 42 women of reproductive age with confirmed ovulatory cycle and body mass index of 18–35 kg/m². Observations revealed no ovulations during 7 months after a single injection of 150 or 300 mg Depo-Provera. The pharmacodynamics and pharmacokinetics data give proof of concept that Depo-Provera (150 mg), when injected subcutaneously every 6 months, may be an effective contraceptive method with up to a 4-week grace period for reinjections.