Females have a plethora of contraception to choose from, including long-term solutions like the IUD and the implant and short-term strategies like the diaphragm and the vaginal ring. For men, it narrows down to only condoms (with a failure rate of close to 20%) and vasectomy which is considered largely irreversible and involves minor surgery. We've been waiting a long time for a male contraceptive, with a variety of approaches making headlines recently.

There are reasons why pharmaceutical companies have not been quick to invest in bringing male contraceptives to market. Creating a male method is an onerous process. Female birth control largely works by preventing the ovulation of one egg, once a month. But men produce millions of sperm every day and bringing that number down to zero involves the careful experimentation of various hormones, dosing and intervals, and it takes awhile to get it right.

A male contraceptive pill has been developed which is effective, safe and does not harm sex drive, scientists have announced. In what has been described as a “major step forward”, the drug was successfully tested on 83 men for a month for the first time. The main hopes for future contraceptive developments are resting on a long-acting injection or topical gel, both of which are also under development.

However, the new drug, called dimethandrolone undecanoate, or DMAU, includes a long-chain fatty acid which slows down the clearance, allowing just one dose to be taken each day. Like the pill for women, the experimental pill combines activity of an androgen - a male hormone such as testosterone - and a progestin.

Investigators at the University of Washington Medical Centre tested three doses of DMAU - 100, 200 and 400mg - on 100 healthy men between 18 to 50 years old, 83 of whom completed the study.

They were subject to blood sampling for hormone and cholesterol testing on the first and last days of the study. At the highest dose of DMAU tested, 400 mg, subjects showed "marked suppression" of levels of their testosterone and two hormones required for sperm production. The results showed that the pill worked only if taken with food.

Past surveys suggest that at least 50% of men would use new male contraceptives, with men in stable relationships being the most open to taking a daily pill. While some scientists are exploring hormonal options for men that suppress testosterone and sperm production, other researchers are exploring non-hormonal options. In India, an injection procedure that stops sperm from escaping the testes is awaiting government approval, and in the U.S. a start-up and a non-profit organization are working on similar approaches.

"With this non-hormonal approach, sperms are unaffected so the contraception is likely to be readily reversible once the medication has been stopped," a scientist commented.

Some of the work related to the development of this pill has already been accomplished. And there's already a pill on the market that blocks the α1A-adrenoceptor as treatment for a condition called benign prostatic hyperplasia, or an enlarged prostate. The next step in the research is to develop the pill to block the second protein.

If this stage is successful, the team will be looking to start clinical trials, estimating that, if all goes well, the drug could be on the market in as soon as 5 to 10 years.