Male lactation is the production of breast milk by those of the male gender. This is a rare and unusual event, but it has been observed in humans in several cases.

Evidence of Non-Human Male Lactation
Male Lactation, an article by Dr. Patty Stuart Macadam of the University of Toronto in the Fall 1996 issue of Compleat Mother, states that the feature is somewhat common in Dayak fruit bats, a rare species. In 1992, 18 such bats were discovered in Malaysia, ten of which were male. All ten male bats were capable of lactation.

History of Male Lactation in Humans
Male lactation was first noted by the German explorer Alexander Freiherr von Humboldt in 1858. In his diaries of that year, he wrote of a 32 year old man in northern Burma who breastfed his child for five months in the absence of a mother or wet nurse. Also in 1858, David Livingstone published reports of the same phenomenon in the Scottish highlands. Recently, in 1982, a 55 year old man in Baltimore, Maryland was noted for being the wet nurse of the children of his mistress. In 2002, an article with photographic evidence appeared in a Zaire newspaper, showing a local man providing breastmilk for his infant son.

There are many anecdotal cases of male lactation beyond these, including several articles in modern health magazines and current health books by men claiming to have mastered the technique.

Do Males Produce Normal Milk?
The milk excreted by males is virtually identical to milk produced by females, with only a few relatively unimportant enzymes missing (Macadam, Compleat Mother, 1986); aside from these missing enzymes, male lactation in all measured species is identical to female lactation.

Inducing Male Lactation
According to recent studies (Macadam in Compleat Mother), a significant part of lactation is psychological; a will to breastfeed is a major part in being able to provide milk for an infant. Doctors thus recommend the following program to encourage lactation in males, although male lactation in humans is not recommended unless necessary for the care of an infant.

1. Believe in lactation. Males should try to imagine their nipples producing milk. Often, a rhythm of doing this works, modeled after the feeding times of a normal wet nurse.
2. Arouse the nipples regularly. At the same time as imagining lactation, a male should exercise and arouse his nipples. A tugging should occur at regular intervals (every two to three seconds) for a period of fifteen to twenty minutes. Soreness is likely, but it is necessary.
3. Ingest a healty, balanced diet with a lot of protein. The male body will basically be releasing protein, so consuming a strong diet with protein supplementation will help with the biochemical needs of lactation.

Benefits of Male Lactation
The advantages of male lactation are many. For starters, male lactation would promote a type of emotional bonding between father and child that is now available only to the mother and child. In addition, it would provide many of the benefits that a child often misses in the absence of breastfeeding, such as a stronger immune system and decreased disease susceptibility. In the first world, most mothers choose not to breastfeed, either for career purposes, illnesses, failure to breastfeed, or lack of interest; male lactation could potentially fill this role.

The Psychological Barrier
It is quite likely that many males (and probably many females) reading this article are repulsed by the concept of male lactation. It should be mentioned that the primary barrier to this effect is psychological; it is not practiced because so many find it inherently revolting. Since the mother naturally carries the child and her breasts (usually) naturally fill with milk during the childbearing process, it seems natural that it is the mother, NOT the father, that should do the nursing. This statement, however, is psychological and sociological in nature, though, and is not based on the true physical nature of the situation.

Male lactation is physically possible, and it should be considered especially in situations where parents wish to provide breast milk for the child, but the mother is unable to provide the milk.