You don’t see many men in the lactation section of Buy Buy Baby, but that’s where I was when I bought my first breast pump. I wasn’t there on a mission for a pregnant wife or girlfriend. I was preparing to test an obscure secret of biology: Men can lactate. While not widely known, the image of the breast-feeding male dates back thousands of years. The Bible provides one in Numbers 11:12, where Moses complains to God about the difficulties of watching over the freed slaves in the Sinai wilderness: “Have I begotten them, that you should say to me, Carry them in your bosom, as a nursing father bears the sucking child … ?” (There’s a more literal reference in the Talmud.) In more recent times, Charles Darwin himself observed that “it is well known that in the males of all mammals, including man, rudimentary mammæ exist. These in several instances have become well developed, and have yielded a copious supply of milk.”

Since Darwin, male lactation has been observed in other animals, including the Dayak fruit bat, the domestic goat, and the guinea pig. Yet this fact of nature has been ignored, to the point where its opposite assumption—that men are physically incapable of producing milk—has been used to advocate for government control of human relationships. “We can … agree that men can’t breastfeed,” said attorney David Thompson, arguing against the 2010 appeal of California’s gay-marriage ban, “and breastfeeding clearly has benefits for children in that it provides sources of immunity that are beneficial to children.”

The more I learned about male lactation, the more curious I became. I’m 33 years old and single in New York City, a cross between Carrie Bradshaw and George Costanza—if there’s such a thing as a male biological clock, mine has started ticking. I know I can’t birth a child myself, but what if I could bear one to suck at my bosom? Could my rudimentary mammae yield a copious supply of milk?

Given the challenge before me, I was pleased to learn that the production of breast milk is a relatively simple process. The breast tissue of both men and women contains small clusters of alveoli that produce milk in response to a hormone produced by the pituitary gland called prolactin. Under normal circumstances, women have about one-third more prolactin coursing through their veins than men, and during pregnancy, they make more than 10 times as much. The reproductive prolactin spike causes the breasts to swell and produce milk. In theory, you don’t have to be pregnant to start lactating—all you need is the hormone rush.

In fact, many babies—both boys and girls—spontaneously lactate in the weeks after birth, a phenomenon known as Witch’s Milk. This is caused by excess prolactin from the mother’s body that passes through the placenta. Sometimes it can take several weeks for a newborn to filter out the hormones.

A small number of older boys and men also release a milky fluid from their nipples, in a condition called male galactorrhea. The fluid seems to be broadly similar to the milk produced by women: A 1981 study conducted at the University of Western Australia examined the milk of a 27-year-old man and found it contained very womanly levels of protein, lactose, and electrolytes. The condition appears most often during puberty, when a more general surge in hormones can lead to a surplus of prolactin. It can also be caused by hypothyroidism, which may change the output of the pituitary gland unexpectedly.

Some kinds of liver disease also cause male lactation. Cirrhosis can inhibit the body’s ability to remove hormones from the blood stream, leading to unusual buildups. In a 1995 article on father’s milk, Jared Diamond cites the story of 500 Japanese POWs during World War II who all started to lactate after months of starvation. The nutritional stress may have suppressed their normal liver function, Diamond argued, and created its own artificial prolactin surge.

“I might actually be able to do this,” I thought to myself. It all sounded straightforward—I just needed a big surge of prolactin. Where would I get it? Prolactin isn’t commonly available as a pill or shot, but there are some prescription meds that stimulate its production. Drugs like Reglan (metoclopramide) and Motilium (domperidone) are prescribed to women who have difficulty producing milk or have adopted a newborn and want to breast-feed. They come with potential side effects including insomnia, nervousness, and a movement disorder that causes irrepressible twitching.

The problem is, these pills aren’t typically prescribed to 33-year-old writers who just happen to be curious about filling their chests with milk. When I asked a lactation consultant for advice, she was hesitant to provide any. Breast-feeding is still stigmatized in many parts of America, she said, and she didn’t want to worsen its reputation. She also reminded me that while I could give myself a pharmaceutical boost, it would require a doctor’s approval. I could have tried more aggressively to procure some Reglan, but as I imagined myself dealing with increased mood swings, possible depression, and my body twitching out of control, I became afraid.

Fortunately, there’s a more natural way to stimulate milk production. When a baby (or a non-baby) sucks on a nipple, the movement activates mechanoreceptors that connect to the brain and stimulate the pituitary gland. Adoptive mothers can use a breast pump to access this nipple-based lactation process: A standard pumping schedule can take up to two months and ideally involves pumping each breast every three hours around the clock. Here’s the rub: Men have the same receptors in their nipples as women, so the pumping method should work just as well for us.

At least that was the thinking of Ragnar Bengtsson, a Swedish college student who attained a brief infamy in 2009 when he tried to make himself lactate as part of an attempt to measure the contents of male breast milk. Bengtsson didn’t take any hormone supplements and instead tried to induce lactation by pumping himself every three hours. After more than two months, Bengtsson gave up. He never produced a drop of milk.

Bengtsson’s failure shouldn’t be that surprising. Even for women, the process can be difficult. A comprehensive survey of induced lactation in women hasn’t been done, but a researcher at Canada’s Goldfarb Breastfeeding Clinic monitored 228 surrogate and adoptive mothers and found only 31 percent were able to reach full milk production. (Most women were able to produce at least some breast milk.) Since men don’t go through the same period of breast development during puberty—when lobules become more numerous and the fatty tissue that supports them bulks up—it’s highly unlikely a man could ever produce the same volume of milk as a woman. In any case, Bengtsson’s failed quest didn’t win him many admirers in the United States. The talk show host Cenk Uygur spoke for lots of American men when he called the Swede a “pussy.”

That word, and Bengtsson’s failure, echoed in my head as I imagined my manly frame softening with mother’s milk. Or not producing any milk at all. I still felt good about my chances: For every dry-nippled Bengtsson there was a counter-example, like the Sri Lankan man who breast-fed his infant daughter after his wife died in 2002. Men who claimed to have experienced spontaneous lactation or successfully pumped for milk posted their Eureka moments to the comments for related articles online. I’ve even found some YouTube videos of men squeezing milk from their nipples.

I was scared of side effects from the hard-core pharmaceuticals, so I decided to repeat Bengtsson’s experiment with the addition of some herbal supplements. I settled on liquid fenugreek extract, an organic lactation booster from Whole Foods. “I started taking More Milk Plus capsules almost a week ago and within 24 hours I was able to pump twice the amount I would have normally pumped,” exclaimed one of the (presumably female) testimonials on the company website—a promising omen. I took triple the normal dose, swallowing three gel caps four times a day. I also drank a lactation tea a few times daily, which had the same dusky licorice flavor as the pills, and started consuming putative milk-boosting foods like kale, oatmeal, and beer.

It was strange to apply a breast pump for the first time. My nipples aren’t accustomed to regular stimulation, and though I felt like I was defying the natural order, pumping was surprisingly pleasant. Nipples are filled with nerve endings, after all, and the gentle upward tug of the pump was both comforting and erotic.

As the days went on, the comfort turned into monotony. The happy surprise of those first few upward pulls became predictable, a mechanical intrusion into my workday. I couldn’t afford the electric pumps, which can cost up to $300, and had to settle for a manual one. It was impossible to do anything useful while holding the pump’s suction cup to my chest with one hand and operating the handle with the other. I struggled with the routine, and the loss of at least two or three productive hours each day.

The herbal supplements were no help, either. After seven weeks, I never wanted to taste fenugreek again, and I still hadn’t produced any milk. If I was going to get over the hormonal hump, it seemed like I’d have to double the frequency of my pumping at least, and start waking up every three hours throughout the night for bonus sessions. I started to have doubts. Was this really worth it?

And then I realized I was missing something essential: a child. For all our assumptions about breast-feeding, the one abiding truth is that it exists to nourish and comfort new life. The walls of gender could be broken down, but without a child to benefit, what was the point? I’d read with great interest the anthropologist Barry Hewlett’s account of his time with the Aka Pygmy tribe in central Africa, where fathers suckle their children when the mothers are away. Not all of the men lactated, but they seemed to understand the gesture is as important emotionally as it is physiologically. Aka men are within reach of their children 47 percent of the time—more than for any other group in the world, according to Hewlett. That sounded beautiful to me. But without a child of my own, I couldn’t compare myself to the Aka. Good reader, I lost heart.

Maybe one day I’ll try again to climb over the gender wall, this time risking the mortification of a swollen breast and the ominous side effects of hormone-boosting pharmaceuticals. It would be nice to have a better reason than curiosity, I think. Perhaps a little baby—someone in need of sustenance and intimacy, searching for a breast to nuzzle. Yours or mine could do.

Also in Slate, Chris Beam explained whether women with breast implants can breast-feed, and Sydney Speisel cast a skeptical eye on some of the more exuberant claims about the benefits of breast-feeding. In 2007, Emily Anthes explained the effects of fatherhood on men’s bodies and brains.