Men simply don’t have an effective, reversible form of birth control comparable to the female pill. What’s taking so long?
When it comes to controlling our own fertility, it sure sucks being a guy.
Since the 1960s, women have had access to safe, effective, reversible, hormonal birth control. And it seems like every year there’s a new TV commercial selling women the latest contraceptive pill, patch, shot, or implant.
A few months ago I read about encouraging advances in the science of male contraception. That led me on a long search to speak to the leading minds in the field.
As readers know, I had a vasectomy several years ago. But I have several buddies who are either on the fence about wanting kids or don’t want them right this second. So, for those guys, I wanted to ask these scientists: What’s taking so long?
Presently, when it comes to keeping our sperm from reaching a partner’s egg, we have four options, each of them with major downsides.
First: abstinence. Look, if Catholic priests can’t stick to this standard, you shouldn’t, either.
Second: pull ’n’ pray. Use this method and you’ll soon unwrap neckties every third Sunday in June.
Third: condoms. Reversible? Check. Effective? Sure, as long as they don’t break. But let’s face it, nobody likes using condoms, especially when you’re in a long-term relationship.
Fourth: vasectomy. Ridiculously effective, yet permanent. They’re great for when you’re absolutely sure you never want to attend a parent-teacher conference, but not so good if you’re not so sure.
Men simply don’t have an effective, reversible form of birth control comparable to the female pill. Why has it taken so long to develop these methods for men?
According to the docs, the challenge is twofold. The first lies in differences in the biology of men and women. During pregnancy, the hormone progesterone naturally halts ovulation. Men, however, never stop producing sperm.
The second challenge lies in numbers. A woman releases just one egg during her cycle; men produce a thousand sperm every second. Researchers into male contraception have to deal with literally billions of egg-seeking swimmers.
But fortunately for us, they’re getting results. Sure, there are some obstacles to overcome—mainly funding for further research and a lack of pharmaceutical companies taking an interest in the field—but, as scientists tell me, we could be only a few years away from temporary, reversible male contraceptives.
When used correctly, these new contraceptives should be just as effective as their female counterparts. And like the Pill, they will protect only against pregnancy, not STDs—which means condoms won’t be history just yet.
Dr. Diana Blithe, program director of the Contraceptive Development Research Centers Program funded by the National Institutes of Health, says the most effective known method is to administer some sort of progestin molecule, a synthetic hormone similar in function to progesterone, which regulates pregnancy in women.
In men, progestin suppresses the body’s ability to make enough testosterone to support sperm production, so sperm count levels drop well below what’s needed to fertilize an egg under normal circumstances.
At this point, it would take a large-scale study for this method to get FDA approval. When administering progestin to men, it’s necessary to administer back some androgen like testosterone, because without it, Blithe says, a man would begin to experience hot flashes and have trouble achieving an erection. Testosterone is currently commercially available as a transdermal gel, but development of an oral form remains a challenge.
There are several ways to administer the progestin: daily pills or gels, and long-lasting implants or injections. Men could choose the method they prefer. Blithe thinks the long-lasting versions would make a better option; unlike pills, the injection and implant don’t depend on remembering to take it—a major reason why the Pill often fails.
The testosterone-replacement part, however, could be effective in daily dosage form. “If you don’t take it, you start to feel the effects,” explains Blithe. “That’s self-motivating in that respect.”
Dr. John Amory is an Associate Professor of Medicine at the University of Washington, where he’s currently in the middle of clinical trials testing a “gel-gel” combination of progesterone and testosterone.
How does this gel work?
First, a simple explanation of male fertility: To make sperm, the brain first tells the pituitary gland to secrete two hormones, LH and FSH. In men, those hormones affect the testes, signaling them to produce sperm and testosterone. The testosterone then gets into the bloodstream and goes back to the pituitary, which helps regulate its own production.
The gel approach would simply boost the amount of testosterone in the man’s bloodstream.
“It’s what we call a negative-feedback loop,” explains Amory. “If you give somebody testosterone from the outside, in a dose slightly more than his body would make, it will suppress the production of LH and FSH in the pituitary. That deprives the testis of the signals that are required for spermatogenesis.”
Amory’s current study is looking into the effectiveness of using two gels to suppress sperm production. One gel contains progesterone; the other, testosterone. Men apply the gels once a day.
“It’s like putting on sunscreen,” Amory says.
It should take about two to three months for the gel treatment to become effective. And the good news is, it should be completely reversible. Men should begin producing sperm again about three to six months after they stop using the gels.
But it will still take several months before Amory and his researchers get their results.
Another approach is being examined by Dr. Debra Wolgemuth, Professor of Genetics and Development at Columbia University. For the past five years, she’s researched new methods in male contraception; one of the most promising involves the use of inhibitors of retinoids, the metabolites of vitamin A.
Her investigation into these retinoid inhibitors as a contraceptive began when she came across a paper showing that scientists at Bristol-Myers Squibb had synthesized compounds that proved toxic in the testes. A light bulb went on:
“One person’s toxin can be another person’s contraceptive,” Wolgemuth laughed in a phone interview.
As you probably know, vitamin A is a compound found in foods like carrots, liver, and broccoli, but it has to be converted into an active form before it can be used in biological processes. One of its active forms is retinoic acid, which affects processes such as gene expression.
In the testes, retinoic acid binds to proteins in the cell called retinoid acid receptors, which regulate the production of various proteins needed for sperm formation. Block those proteins, and sperm don’t form correctly, making the male infertile.
In earlier studies, Wolgemuth found that male mice with a mutation at one of the retinoid acid receptors were sterile, while females with the same mutation were still fertile.
Wolgemuth’s latest scientific paper shows that using retinoid inhibitors to induce infertility is reversible, one of the key components to creating a marketable contraceptive.
“We’re trying to ask questions like, How long can we keep the mice on the drug and still allow them to regain fertility when we stop? And we’re also interested in how low a dose we can give,” she said.
So what’s causing the holdup? The research is there, the resources may even occur naturally, and—trust me—the market is ready. Blithe agrees: there are certainly plenty of people interested in male contraceptive options. That’s especially true with couples where the woman can’t take hormonal contraceptives for health reasons such as diabetes or obesity.
But the Pill has been around since the 1960s. So why has it taken so long to get male contraception to market? The joke in the male contraceptive field goes that we’ve always been five years away from male contraception being available.
I contacted representatives from Merck, maker of Implanon and Nuvaring, and Bayer Healthcare Pharmaceuticals, makers of Yaz and Mirena. Reps from the companies wrote in separate emails that they’re not currently researching male contraceptive methods. When asked why not, the reps didn’t respond. Bummer.
Besides the science challenges mentioned earlier, Blithe believes there are some barriers at pharmaceutical companies. The developed techniques couldn’t be too expensive for men to afford them. And, Blithe notes, there’s a lot more money to be made in cancer and lipid-lowering drugs than in male contraception.
“So when you say it’s five years away, well, it could be a lot sooner, it could be a lot longer, depending on whether a company will take that responsibility,” she said.
Are you listening, Big Pharma?
An alternate version of this piece appeared on AlterNet.