Why Do Men Have Nipples?

This article was medically reviewed by Dr. Justin Lehmiller, a social psychologist, researcher and award-winning educator. For more information:
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Have you ever wondered why guys have nipples, considering they don’t use them for anything? They don’t nurse babies with them like women do.

Come to think of it, there’s a strange double-standard when it comes to nipples in that men can show off their useless nips with no problem. However, when a woman does it (think Janet Jackson’s ‘wardrobe malfunction’), there’s a huge fuss. So not only are male nipples useless, they’re somehow considered benign when compared to women’s nipples. Weird, isn’t it?

Why Men Have Nipples

It all starts in the embryo.

When you’re an itty-bitty baby in your mommy’s tummy, everyone begins developing certain biological structures in the first few weeks after conception, including itty-bitty embryonic nipples. The biological structure of breasts and nipples starts developing between the 4th and 6th week of development, before the development of the genes that dictate your sex, which come around week 7. Very basically put; you have nipples before you ever start to develop your specific male or female (sometimes a mix of both) traits.

After being born, baby breasts and nipples look the exact same, regardless of sex. They don’t undergo any significant change in appearance until puberty: for both boys and girls, this is a time when nipples enlarge, however, female nipples grow more, and the ducts inside the breasts enlarge and reshape the breast. Meanwhile, male ducts shrink and their nipples become more or less uniform. Both men and women end up with varying nipple shapes and sizes due to their individual developments. 

Why Males Didn’t Evolve Without Them

In evolutionary terms, having nipples is essential if a fetus develops toward the female form, given their role in breastfeeding. This is probably why the nipples start developing so early. However, there’s no advantage or disadvantage to having nipples that do not serve a functional purpose, which likely explains why males still have them. 

The male nipple is just a byproduct (or, in evolutionary terms, a “spandrel”). They’re not really needed for anything, but they don’t cause any problems either, so there’s no reason for the body to make them disappear.

Do They Serve Any Purpose, Then?

It depends on what you think they’re useful for. Assuming that ‘giving milk’ is the benchmark of a nipple’s purpose, some men can actually do that, but only under very specific and rare circumstances. For instance, some men’s nipples will produce milk if they’re experiencing a hormonal imbalance.

Likewise, some men, if recovering from starvation or extreme malnourishment may also lactate due to extreme hormonal swings. In these cases, research suggests that the milk that comes from their nipples is very similar to the milk that comes from mothers who are lactating.

Aside from possibly (rarely) giving milk, male nipples do have an alternative use: pleasure. Many (but not all) men find that their nipples are an erogenous zone. For example, they can be teased during foreplay and lovemaking, and some men and women enjoy kinkier nipple activities like wearing nipple clamps.

Does That Mean Men Can Get Breast Cancer?

It’s pretty rare, but yes, they can. Of all breast cancer diagnoses, 0.5% to 1% are men, while the other 99.5% to 99% are women. Because it’s so unlikely, men who do get breast cancer often don’t find out until it reaches a very advanced stage, so if you (a guy reading this) notice any unusual changes in your chest, like a lump in your breast tissue, nipple discharge or cracking on the skin of your nipple, see a doctor to be safe.