The top reason many women stop breast-feeding is not making enough milk, but most people assume that women can make more if they just try harder. Mothers who have moved heaven and earth to make only a few more drops of milk know how wrong this is.

The science of milk

To build a “milk factory,” hormones and receptors must be made in the right amount, time, and place they’re needed. Estrogen and progesterone stimulate breast development during puberty and pregnancy. Prolactin contributes during pregnancy and then drives milk production along with insulin and cortisol. Oxytocin propels milk through the ducts. If any of these hormonal roles fail, there may not enough milk.

"Not being able to make enough milk is not normal and a sign that something is off."

Low thyroid hormone can interfere with prolactin and oxytocin, reducing milk production and milk ejection, but mothers may not be flagged because the laboratory ranges are often broader than what is considered optimal for reproduction (TSH 0.5-2.5ng/dL). Insulin resistance, which occurs with type-2 and gestational diabetes, can slow milk production mildly to severely.

Hyperandrogenism (excess male hormones) can suppress breast development and milk production. Polycystic Ovary Syndrome (PCOS), the leading cause of female infertility, can result in low progesterone, hyperandrogenism, and insulin resistance. The breasts may not mature properly, resulting in underdevelopment, unusual shapes, or asymmetry that may reduce milk production capability.

Treatment tips

When low supply due to hormone imbalances is suspected, the best treatment strategy starts with addressing the underlying problem. This may involve lab tests, medications, diet changes or galactogogues, accompanied by removing milk frequently with breastfeeding, pumping, or hand-expression.

Never accept someone who tells you that you simply need to “try harder.” Not being able to make enough milk is not normal and a sign that something is off. A board certified lactation consultant (IBCLC) can work with doctors to find answers. Most importantly, connect with other low supply mothers for support and encouragement. It can make all the difference.