New Study Gives Male Hormonal Birth Control a Shot

For decades, the responsibility of birth control has fallen primarily on the female. Whether it’s in a pill, ring, implant or shot, many women choose hormonal contraception for its convenience and efficacy. However, negative side effects such as stroke and blood clots make it a high-risk option for some women. Plus, some experience severe mood swings, weight gain and acne as a result of hormonal contraceptives.

In light of the above, many feel that there’s got to be a better way to prevent pregnancy that targets men.

Sure, men can use condoms or the withdrawal method to prevent fertilization. But some find these options inconvenient and unreliable for long-term use. What about a vasectomy? For many young men, this option severely limits their chances of starting a family when they’re finally ready.

Medical researchers are now exploring new birth control options for men. In fact, a recent article published in The Journal of Clinical Endocrinology and Metabolism reported the results of a trial of a hormonal birth control shot that lowers fertility. The study involved 320 healthy men with normal sperm counts who were in monogamous relationships with female partners.

Lowered Sperm Count

During the study, an injection of 1,000 milligrams of a synthetic form of testosterone and 200 milligrams of norethisterone enanthate was administered to the test subjects every eight weeks. The goal of the injection was to lower the participants’ sperm count to less than 1 million per milliliter to prevent pregnancy. The shot effectively held the sperm count at 1 million per milliliter or less within 24 weeks for 274 of the test subjects. The contraceptive method was effective in nearly 96% of continuing users. However, this efficacy rate is still considerably lower than the 99% reported with the proper use of reversible female contraceptives such as birth control pills, IUDs and implants.

Side Effect Analysis

Study participants reported 1,491 negative side effects, which included injection site pain, acne and muscle pain. However, the researchers reported that nearly 39% of these symptoms were unrelated to the treatments. Serious negative side effects included one case of depression and one case of an abnormally fast, irregular heartbeat. Twenty men dropped out of the study early due to side effects.

In March 2011, the study was ended early due to the mood-related side effects. However, it’s encouraging to note that more than 75% of participants reported they were willing to use this method of birth control at the end of the study.

Fertility Recovery

Once the participants stopped getting the injections, their sperm counts were monitored. Fortunately for most men, they returned to fertility during a recovery period. The minimum recovery time was about 12 weeks after the last injection while the average time was about 26 weeks. After 52 weeks in recovery, 8 test subjects had not returned to fertility.

While we don’t expect to see any new male birth control drugs on the market in the immediate future, this study proves the efficacy of using hormone injections to lower the sperm count and prevent pregnancy. Researchers are now comparing the risk of fertility loss for men with the potentially fatal side effects associated with hormonal birth control for women. Additional tests and analyses must be completed before anything new is brought to market. So for now, ladies, hormonal birth control is still just for you.

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To learn more about birth control, call Arizona OB/GYN Affiliates (AOA) at 602-343-6174 or visit