Prolactin is a polypeptide hormone produced by the pituitary gland, an endocrine organ located at the base of the brain. While it performs many functions, its most recognized role is stimulating the mammary glands to produce milk, a process known as lactation. When lactation is challenging, people often seek substances, called galactagogues, to intentionally raise the circulating levels of this hormone.
The Role of Prolactin in Lactation
The primary function of prolactin is to prepare the breast tissue and initiate milk production. Throughout pregnancy, rising levels of prolactin, alongside estrogen and progesterone, stimulate the growth of the mammary alveoli, which are the milk-producing structures within the breast. Despite high prolactin levels during this time, milk secretion is suppressed because the high levels of progesterone inhibit prolactin’s action on the mammary receptors.
Following childbirth, the expulsion of the placenta causes a rapid drop in progesterone. This allows prolactin to activate the alveolar cells, starting the secretion of milk, a process known as lactogenesis II. Continued milk production is sustained by the frequent removal of milk from the breast. This removal sends signals that trigger a surge in prolactin release from the pituitary gland.
Common Supplements Known to Increase Prolactin
Many substances, both herbal and pharmaceutical, have been used to enhance milk supply by increasing prolactin levels. These substances are collectively known as galactagogues. Fenugreek (Trigonella foenum-graecum) is the most widely used herbal galactagogue, traditionally consumed as a seed or capsule.
Several other herbal options are commonly used.
- Blessed Thistle (Cnicus benedictus) is frequently used in combination with fenugreek.
- Goat’s Rue (Galega officinalis) supports mammary tissue development and milk flow.
- Fennel is often consumed in teas.
- Moringa is a nutrient-dense leaf thought to support lactation.
Certain prescription medications are sometimes used for their strong galactagogue effects. Drugs like metoclopramide and domperidone were originally developed for treating gastrointestinal issues. A common side effect of these drugs is a significant elevation in prolactin levels, leading to their off-label use to support milk supply.
Biological Mechanisms of Prolactin Stimulation
The mechanism by which supplements increase prolactin focuses on removing the body’s natural brake on the hormone. Prolactin secretion is normally suppressed by the neurotransmitter dopamine, which binds to D2 receptors on the lactotroph cells of the anterior pituitary gland. Therefore, a primary strategy for increasing prolactin is to inhibit the action of dopamine.
Pharmaceutical galactagogues, such as metoclopramide and domperidone, function as dopamine D2 receptor antagonists. By blocking these receptors, the drugs prevent dopamine from inhibiting the pituitary gland. This results in a rise in prolactin release into the bloodstream, which is the most direct pathway to increasing the hormone’s concentration.
Many herbal supplements work through different, sometimes overlapping, pathways. Fenugreek contains steroidal saponins, which may possess phytoestrogenic properties that mimic estrogen. This action can stimulate the growth of mammary tissue and influence prolactin release. Other herbal compounds are hypothesized to act as mild dopamine antagonists or to support overall hormonal balance necessary for sustained milk production.
Safety, Dosage, and Contraindications
Anyone considering a supplement to increase prolactin should first consult a healthcare provider or a certified lactation consultant to rule out other causes of low milk supply. Dosage for herbal galactagogues is not standardized, so it is important to follow manufacturer instructions and start with the lowest effective dose. The onset of effects is often seen within one to three days.
Certain supplements carry specific warnings. Fenugreek may cause a maple syrup odor in sweat and urine, and can lower blood glucose levels, requiring caution for individuals with diabetes. Goat’s Rue is botanically related to peanuts and should be avoided by those with known peanut allergies.
General contraindications for galactagogues include a history of hormone-sensitive cancers or taking medications that interact with the supplement, such as blood thinners or specific cardiac medications. Many herbal supplements should be avoided during pregnancy, as some compounds may have uterine-stimulating effects. If side effects like digestive upset, headaches, or changes in mood occur, the supplement should be discontinued immediately.