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.