Researchers are trying to provide a promising approach to male contraception that involves immobilizing sperm.
Derek Berwin/Getty Images
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Derek Berwin/Getty Images
Researchers are trying to provide a promising approach to male contraception that involves immobilizing sperm.
Derek Berwin/Getty Images
Existing male contraceptive options are condoms, vasectomy or abstinence.
So the job of unwanted pregnancies often falls to women who can check their ovulation daily, get an IUD implanted, wear vaginal rings, use a diaphragm, or, when all else fails, the morning after pill.
Scientists are more successful as sperm producers. A paper published in the journal Dec. 14 Nature CommunicationsNew approaches to male contraception show promising results. The researchers proved that a compound that inhibits the sperm enzyme’s need to swim, suggesting a way of action, a form of temporary contraception. (Although tested in mice, many species have the same enzyme as human males.
“Our lab found a switch to move sperm,” says Jochen Buck, a pharmacologist at Weill Cornell Medicine and co-author on the paper, “And now we’ve developed a compound that prevents it.”
The potential potency of the compound as a male contraceptive has been discovered in the past. Five years ago, a student in Buck’s lab wanted to test it on mice as a possible treatment for a damaged eye. But the student was terrified of the mice so he asked the second doc, Melanie Balbach, for help. Balbach agreed that he could also check what happened to the sperm of male mice, since he knew the drug was acting on an enzyme related to male fertility.
Balbach presented the results to Buck and lab director Lonny Levin at a lab meeting the following week. They were amazed: After the male mice were injected with the mixture, their sperm did not move.
Lonny’s reaction was, “Wow! This means we could develop a male contraceptive,'” Buck recalls, “and my reaction was, ‘Lonny, that’s better. “We can have a male contraceptive.”
The drugged sperm stopped swimming, slowing their tails to a quick twitching thrashing. In men, this might mean never making it out of the vaginal canal past the cervix into the uterus. Further research has shown that it is fast acting, taking effect in about fifteen minutes. And it was time – it stayed in the system for several hours.
During those hours, I had plenty of sex with both male and female mice in the study. Within 2.5 hours of getting the medication, it was 100% effective in preventing pregnancies. Within 3.5 hours it was 91% effective.
Goat has high hopes that the same will work in humans. “The prediction is after half an hour or after five hours or after eight hours; [their] they don’t move the narrative – and after a day or two they are back to normal,” he says.
Non-federal experts find the study promising, but caution that drugs that work in mice don’t always work in humans.
“It is very early,” said Dr. Michael Eisenberg, urologist and director of the Male Reproductive Medicine and Surgery Program at Stanford Medicine. “Note that the pill could reduce the potency of stimulating fertility, whenever a study is done in mice, you need to repeat it and make it valid in humans as well.”
Dr. John Amory, a professor of medicine at the University of Washington who is currently researching a form of hormonal male contraception for humans, says the new compound is a “great idea.”
“It’s an open question how well it would translate from mice to humans,” he adds. “There are differences in reproductive physiology between species, but it’s worth trying.”
The drug in the seed is pelted by an enzyme that is the same for many mammals. Researchers are now working in tunnels, and hope to start human trials in two to three years.
The demand for male contraceptives is there, Eisenberg says. “There’s no doubt it’s a big job. When you’re exploring people, especially young people, it’s very important to have something in them. [more] options. ”
Some other experimental ideas, such as hormonal pills, needles and injections for men, can take weeks to work. Some can cause mood disorders, affect alcohol tolerance, or shrink men’s testicles. When male contraceptives are available to healthy men, “the tolerance of the side effects is going to be too much, too much,” says Eisenberg.[The gains] to be specific enough without many of these off-target effects.”
The side effects of this new potential treatment in men are not yet known, but having a male contraceptive treatment that can be taken as needed can reduce those risks, says Amory. Unlike the hormonal approach, which has to be taken daily, “you only have to take it episodically, so you have less to worry about long-term toxicities.”
According to the researchers, the study subjects were doing well. “Look, our rats will never mate unless they are in pain,” said Buck. If successful, he says, he hopes some drug will be available eight years from now.
Is this realistic? It can be done. “It’s a joke in the field: it’s been a male contraceptive for 5 to 10 years out of the last 40 years,” says Amory. “It’s always just around the corner.” Technology, he says, continues to advance, and eventually society will get there.
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