Fennel: Promoting or Suppressing Lactation?
Generally speaking, fennel does not have the effect of reducing or promoting lactation. Detailed analysis is as follows:

Fennel mainly contains fennel oil, vitamins, minerals, and other components. Although these substances can provide nutrition or aid digestion to some extent, they do not include hormone components or specific bioactive substances that directly affect milk secretion. According to traditional Chinese medicine theory, fennel's effects focus on warming the stomach, dispersing cold, regulating qi, and relieving pain. Its warm nature is primarily used to treat conditions such as cold deficiency of the spleen and stomach or cold-induced qi stagnation. There is no clear evidence or documentation indicating fennel as an ingredient that reduces or promotes lactation.
Although fennel does not affect milk production, lactating women should still pay attention to a balanced diet. It is advisable to consume moderate amounts of soups, such as pork rib soup, carp soup, or chicken soup, to supplement protein and fluids, which can help promote lactation. Additionally, it is recommended to maintain a cheerful mood, wear loose and comfortable undergarments, avoid pressure on the breasts, and maintain proper breast hygiene to prevent breast diseases.