Constraints in the development of contraceptives for men

Considerable efforts have been made to develop a male contraceptive and the studies have provided very useful information in this field. At least five different strategies to develop a male contraceptive have been pursued, na mely: inhibition of sperm production, interference with sperm function, int erruption of sperm transport, prevention of sperm deposition, and preventio n of sperm-egg interaction. Of all these approaches, inhibition of sperm pr oduction by using androgens either alone or in combination with progestins have given the most encouraging results. A number of clinical trials substa ntiate that it is indeed possible to have a reversible, effective and safe hormonal method of contraception. A postmeiotic and epididymal approach to interfere with sperm function or the secretory and metabolic processes of t he epididymis is another attractive option of male contraceptive developmen t. A number of chemical compounds have been identified which interfere with sperm function in the epididymis without affecting sperm production, howev er, the compounds evaluated so far were found to be toxic, interruption of sperm transport through the vas either by vasectomy or percutaneous intrava sal injection of liquids which form cure-in-place plugs is also an attracti ve option. However, reversibility of the methods is of concern in their wid e scale use. The major constraint in developing a long-acting male contraceptive seems t o be the need for greater investment for product development. The clinical trials for evaluating the efficacy and safety of the new products and formu lations stretch over several years and require enormous financial commitmen t. Nevertheless, the long-term gain of having a long-acting reversible cont raceptive for men is far greater than the financial commitments over few ye ars. Male attitude towards using methods of family planning is much more fa vourable than originally believed. The pharmaceutical indus try as well as the health care providers therefore have a greater responsibility. For earl y development of a contraceptive for men, it is essential to increase inves tment and simplify the drug regulatory procedures. The advent of newer tech nologies coupled with the convergent efforts of scientists will certainly m ake it possible to have an effective, safe and reversible male contraceptiv e in the near future.