Simply put, adult breastfeeding is when an adult consumes a woman’s breast milk. There are many reasons why this might happen, and one of the most common ones has to do with health reasons. Breast milk is, for the most part, completely sanitary, cannot spoil, is mostly hypoallergenic, full of nutrition and infection-fighting potential, packed with calories and good fats and proteins, and the list just goes on.
If you are planning on breastfeeding a partner, working as an (adult) wet nurse, or adopting a baby, you may wish to induce lactation. A similar process may be used to encourage milk production if you fear a low milk supply. You can induce lactation with medicine and electric pumping or a TENS unit.
The secret to inducing lactation is creating a proper mental state that will cause the brain to stimulate the breasts to letdown, and mammary glands to make milk. How long it takes to lactate, depends entirely on how long it takes you to decide to create the proper mental state!