Beer used to be recommended to increase milk supply in breastfeeding mothers:

You may have heard the old-fashioned advice to drink a dark beer to boost your milk supply. While this tip has been passed down for generations, the truth is a bit more nuanced. Hops can help increase milk supply, but any benefit comes from the plant itself—not from alcohol.

One of the primary reasons hops (and barley) are considered galactagogues is because they contain specific sugar molecules called polysaccharides. Research suggests that these polysaccharides can stimulate the secretion of prolactin.

Prolactin is the “pro-lactation” hormone produced by the pituitary gland that tells your mammary glands to produce milk. In some animal studies, polysaccharides led to a measurable increase in serum prolactin levels, which provides the scientific basis for the claim that hops can boost supply.

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