"The male birth-control pill has been five years away for 30 years now," says Dr. John Amory, one of the very few male contraceptive researchers in America. It has been 52 years since the female pill debuted, but while every baby has two parents, birth control still remains overwhelmingly women's work.

PROBLEMS:

Sperm are tricky. Unlike a lady's monthly egg, there are millions of wriggly sperm to stop! And unlike eggs, they just keep coming! Female birth control taps into women's normal periods of infertility, but according to nature, dudes' bodies just want to make babies constantly.

Failure is not an option. The stakes for birth control are much higher than other drugs. Most new drugs need to be only somewhat more effective than doing nothing—but the male pill would need to be 99 percent effective. However, it also has to be 100 percent reversible.

Society is not helpful. Be honest: If men had to bear equal responsibility for the outcome of a pregnancy, we would have developed male birth control 2,000 years ago. Instead, scientists need to create a birth control with zero side effects, because research shows that men won't use it otherwise and companies don't want to invest in creating drugs that aren't a sure shot. Without side effects, nearly 50 percent of American men say they would take a birth-control pill.

THE SOLUTIONS:

The Nonhormonal Pill

Dr. Amory spends his days trying to annihilate sperm in various ways, but recently his favorite execution methods involve drugs that are typically used for other issues and coincidentally cause infertility. The anti-cancer drug gamendazole, for example, interrupts sperm maturation. Dr. Amory is currently looking into a de-worming drug that blocks an acid needed to create sperm. Sadly, it also makes people violently ill when they drink alcohol, so... yeah. It needs some tweaking.

The Hormonal Pill

Scientists have already made pills that use progestin and testosterone to stop sperm production. University of California, Los Angeles and the University of Washington have tested this extensively, but because they carry side effects of increased libido and mood changes, pharmaceutical companies have killed the trials because they say the drugs would never sell.

Ancient Herbs

An age-old Indonesian fertility fix has recently been making waves: A native herb called gandarusa appears to make men unfertile. In a long-term study on 100 Indonesian men, it was 100 percent effective and had no side effects... but to be brought to the US, the herb would have to go through many new rounds of research and testing.

Polymer Injections

An Indian doctor named Sujoy Guha is fighting to win validation for a method called RISUG, in which a polymer of styrene and dimethyl sulfoxide is injected into a man's vas deferens. The polymer injures sperm, making them unable to reach the precious egg. The system is currently being tested on 500 Indian men; its international rights were bought by Americans, who call it "Vasalgel." (That sounds like it would stain your trousers.)