[4] The drug is at or beyond the phase III stage of clinical development, but has not been marketed at this time.

[1] The drug was also previously tested successfully as a combined injectable contraceptive with estradiol hexahydrobenzoate, but this formulation was never marketed.

[7] LNG-B has been tested successfully in combination with testosterone buciclate as a long-lasting injectable contraceptive for men as well.

[8][9] LNG-B may have several advantages over depot medroxyprogesterone acetate, including the use of much lower comparative dosages, reduced progestogenic side effects like hypogonadism and amenorrhea, and a more rapid return in fertility following discontinuation.

[7][10] The drug has a well-established safety record owing to the use of levonorgestrel as an oral contraceptive since the 1960s.