Getting Closer to Developing a Birth Control Pill For Men
Baylor College of Medicine's Martin M. Matzuk and his collaborators may have discovered the key to a male birth control pill: cripple the sperm's capacity to swim.
When Carl Djerassi discovered what would become the birth control pill in Mexico City in 1951, the fear, articulated in a U.S. News & World Report cover story from 1966, was that it would unleash “sexual anarchy.” Wives would sleep with the accountant, the gardener, and Zeebo, the freelance birthday clown. With no baby to betray them, their husbands would be none the wiser. Sixty years later, as we continue to search for a male birth control pill, the fear is that men will lie about having taken it.
Soon this fear may be tested. Baylor College of Medicine’s Martin M. Matzuk and his Harvard collaborator, James Bradner, found that an experimental cancer drug made mice infertile without altering their hormone levels. The pill’s trick, published in the August 17th issue of Cell, is to turn sperm into bad swimmers.
Male oral contraceptives have long eluded researchers. While women have one egg on the market at any given moment (sometimes two, which can result in fraternal twins), men produce 1,500 sperm cells every second. That’s 90,000 a minute. 5,400,000 every hour! Hormonal treatments work on men, but they’ve been abandoned because men were dismayed by the side effects: lowered libido, moodiness, and depression. Sound familiar? Yup, add “weight gain” and you’ve got the most common side effects of The Pill, with which nearly eleven million women in America make do.
Matzuk and Bradner’s discovery significantly advances the pursuit for a molecular male contraceptive–something that alters the structure of a protein as opposed to altering hormone levels. The difficulty of developing an effective molecular contraceptive for men is the blood-testis barrier. Much like the blood-brain barrier, there is a membrane between the blood stream and the testes which is very protective and very selective about which molecules it will let through. Bradner came to think that an experimental cancer drug he had been working with at Harvard’s Dana Farber Cancer Institute might just be small enough to pass through. So he sent the synthesized molecule to Matzuk, a fertility scientist in Houston for extensive testing.
The drug is called JQ1, and it was synthesized at Harvard’s Dana Farber Cancer Institute to impede a cancer causing gene called BRD4. As it turns out, that cancer causing gene is in the same family as a gene intimately involved in sperm production, BRDT. When JQ1 is given to mice, it inhibits BRDT, stunting sperm production and ensuring that those that are produced can’t swim so well. Over eighteen months of testing, Matzuk found that the drug didn’t affect testosterone production or mating behavior. And the effects were reversible. When Matzuk stopped giving the mice JQ1, their sperm production returned to normal. If the drug can be modified for human use–something Matzuk and Bradner are working on right now–it’ll be, as the Houston Chronicle said, “the first reversible contraceptive for men since the condom.”
Of course, drugs are like new contractors–they always take ten times longer than you expected. 2011 brought reports of breakthroughs in a contraceptive targetting vitamin A, which assists with the “division and maintenance of sperm cells.” And in 2003, the media proclaimed that “effective and reversible hormonal male contraceptive appears to be within reach,” which wasn’t false; it’s just that that referred to the hormonal male oral contraceptive, and men weren’t willing to go hormonal. Nor should they have been. Nor should anyone.
So this finding with regard to JQ1 is good news. As is a recent survey conducted by contraceptive researcher John Amory at the University of Washington. Two-thirds of the men Amory surveyed, said they would be interested in possibly taking a molecular male oral contraceptive. And 98 percent of women surveyed said they would trust their male partner if he said he was on it.