IUDs can also cause sepsis or perforate the uterus. This is very rare, but still: perforate the uterus.

All of these are FDA-approved contraceptives that are currently on the market and in women’s bodies, and their side effects are just as bad as those that occurred with the injectable male birth control. Nobody halted them in their tracks, saying that perhaps the risks outweighed the benefits. (Women may well decide that for themselves, though; one study found that nearly 40 percent of women stop using the pill within a year of starting it.)

What’s more, we’re learning more about just how serious the side effects of hormonal birth control may be. A recent study of more than a million women published in JAMA Psychiatry found that women who used hormonal birth control were more likely to be prescribed antidepressants. The study’s design has received some criticism, but it nonetheless underscores that for some women, there are tradeoffs between their reproductive freedom and their mental and emotional health.

Not so for men. Though men have an equal responsibility to prevent unwanted pregnancies, they don’t share equally in the consequences, and never have. The burden of birth control has always fallen largely on women’s shoulders; it is their bodies that will bear the consequences if birth control fails. The only currently available birth-control method for men—short of a vasectomy—is a condom. So a man can either wrap it up, or let the lady handle it. And because condoms are significantly less effective than IUDs, implants, contraceptive pills, and rings, it stands to reason that many will choose the surer thing.

Early versions of the hormonal birth-control pill had tons of side effects, enough that, in a trial done in Puerto Rico in the 1950s, the doctor in charge of the trial recommended against its use. However, as Bethy Squires recently reported in a history of birth control side effects for Broadly, a U.S. pharmaceutical company released the same formulation anyway. (Current formulations use far less hormones, but as we’ve seen, still have side effects.) The Broadly piece also notes that the same group of doctors that studied the female pill originally considered one for men, but testicle shrinkage, among other side effects, led them to abandon it. “It was believed women would tolerate side effects better than men, who demanded a better quality of life,” Squires writes.

The side effects in this most recent study were severe in some cases: 21.6 percent of participants got mood swings or some other kind of "emotional disorder," 38 percent had an increased libido, and 23 percent felt pain at the injection site. The crazy thing, though, is that most men wanted to continue using the injectable birth control—more than 80 percent of them said they would choose to use it.* So if men in the past demanded a side-effect-free life, it seems these days many are at least open to taking on the responsibility of birth control themselves. Perhaps the hurdle that remains is that male birth control is unlikely to substantially improve a man’s quality of life. He can already avoid unwanted pregnancies if his partner is on birth control; with his own he’d get the same advantages, except now he might have mood swings. But for women, birth control has been revolutionary. One-third of women’s wage gains since the 1960s can be attributed to the availability of oral contraceptives, according to a report by Planned Parenthood. College enrollment has historically been higher among women who have access to the pill, and “birth control has been estimated to account for more than 30 percent of the increase in the proportion of women in skilled careers from 1970 to 1990,” the report reads. Not to mention that 86 percent of the declining teen-pregnancy rate in the U.S. is thanks to contraception.