Two-year clinical efficacy trial with dose variations of a vas deferens injectable contraceptive for the male

Abstract Contraceptive action of a single intra–vas deferens injection of a specific preparation of styrene maleic anhydride (SMA) dissolved in dimethyl sulphoxide, forming a drug given the name Risug®, has been demonstrated earlier. Now fertility control over a 2-year period with doses having the SMA component ranging from 40 to 70 mg is reported here. The results suggest that pregnancy protection is obtained both in the azoospermic and non-azoospermic states. Side effects are minimal and transient in nature. Libido remains unaltered.