Prolactin is one of the hormones - alongside oxytocin, estrogen, and progesterone - which plays a key role in pregnancy and lactation. Prolactin is made in the pituitary in the brain and performs many functions in our bodies. As a result, prolactin levels increase significantly during pregnancy and lactation.
Low prolactin levels can affect a new mom's milk supply. A healthcare provider may prescribe a drug to increase prolactin levels. If you are concerned about low milk production levels, you should always speak to your healthcare provider in the first instance. Only purchase drugs online after first speaking with your doctor.
Drugs to improve milk supply
Prolactin is the key hormone involved in milk production. Levels of the hormone are elevated in pregnant and lactating women - 80 to 400 ng/mL are considered normal levels for lactating women by most laboratories. Be sure to check with your healthcare provider to clarify what a blood test result means.
There are a number of prescription drugs which can be used to help with milk supply:
- domperidone (Motilium) (note: not approved in the U.S.)
- metoclopramide (Reglan)
- sulpiride (Eglonyl, Dolmatil, Sulpitil, Sulparex, Equemote)
Prolactin levels are regulated by inhibition: inhibiting factors, primarily the brain chemical dopamine, work to keep prolactin at an appropriate level. Drugs that increase milk production block dopamine, leading to increased prolactin levels. However, the drugs aren't effective for all women and won't increase milk supply in women with normal prolactin levels.
Reglan is a commonly used prescription in the US. Depression is a major side effect of this drug, so it's not recommended for moms with a history of depression. All women should be wary of symptoms of depression while taking Reglan. The side effects typically occur over three to four weeks, and go away when the woman stops taking the drug.
Domperidone is not available in the U.S. because the FDA issued a warning against it in 2004. The FDA warned against the drug as it has not been approved in the U.S, although it has been used in Canada and other countries. Domperidone has fewer side effects than Reglan, and has been given Lactation Risk Category L1 (the 'safest') in the 2017 edition of Medications and Mothers' Milk by Thomas Hale, PhD.
Sulpiride is an antipsychotic and antidepressant, which is primarily used to treat schizophrenia. Since the drug also increases prolactin levels, it is also used to increase milk production in some countries, including South Africa and Chile.
Limerick's guide to prolactin and milk supply
Prolactin plays a key role in lactation. Throughout pregnancy, prolactin prepares your breasts to produce milk after birth. However, the placenta produces high levels of estrogen and progesterone, which prevent the prolactin from producing a large amount of milk. After birth, estrogen and progesterone levels reduce, and prolactin increases rapidly - which signals the glands in your breasts to produce milk.
In the first few days after birth, a sudden rise in prolactin kickstarts milk product - although this doesn't maintain a steady milk supply. Regular nursing or expression of milk is needed to maintain a good supply of milk, as milk production works on a 'supply and demand' basis. The more milk that is removed, either by your baby or pumping, the more milk your body makes.
When breastfeeding or expressing milk, the nerves in your breasts signal to your brain to release oxytocin and prolactin. Prolactin signals to the glands in your breasts to produce more milk, while oxytocin is responsible for the 'letdown' reflex.
Prolactin and milk supply
If you continue to express milk regularly, your body will continue to release prolactin and make milk. Prolactin levels are high during pregnancy and immediately after birth. Women's bodies release prolactin in response to stimulation at their breasts, which means that if you don't pump breast milk or nurse, prolactin levels will start to reduce.
The body still produces milk in the first few weeks after birth, and you might experience breast engorgement even without pumping or breastfeeding. However, without regular pumping or breastfeeding, milk production will slow down and eventually stop.
Reduced levels of prolactin can lead to reduced milk supply, which a number of factors can cause:
- Birth control containing estrogen (the combination pill) Changes in the balance of estrogen and prolactin can affect milk production. It has been found that birth control pills containing estrogen can cause reduced milk production.
- Breast surgery Breast surgery near the areola or nipple can cause damage to the nerves in these areas, which signal to the brain to release prolactin
- Depression Depression often causes reduced prolactin levels
- Pacifier use Using a pacifier in the early weeks of breastfeeding can reduce the breast stimulation that you would get from your baby. The more you express milk or breastfeed, the more prolactin your body makes.
- Weight Prolactin levels are often lower in women who are significantly overweight or underweight.
- Smoking Being a smoker can cause decreased prolactin levels.
- Supplementing Giving your baby formula or water between feedings can reduce the signals sent to your brain to release prolactin.
- Numbing creamsNever use a numbing cream to treat sore nipples. It can numb the baby's mouth and the nerves in the breast, preventing them from sending a signal to the brain to release prolactin.
How to increase prolactin levels
The best way to increase prolactin is to pump regularly or nurse your baby. In the first few days after birth, breastfeed or pump every two to three hours. The more your breasts are stimulated, the more prolactin your brain will release. There is anecdotal evidence that certain herbs or foods - such as Fenugreek or oatmeal - can help boost prolactin levels. However, there is no conclusive scientific evidence for this.
While prolactin is crucial to lactation, it isn't the only important factor for a healthy milk supply. Stimulation of the breasts and frequent removal of milk are equally important when it comes to maintaining a good milk supply.
Prolactin and resuming menstruation
Breastfeeding moms have high prolactin levels and low estrogen levels. The relative levels of each of these hormones stop your period and maintain milk supply. If you breastfeed exclusively, your period might be absent for many months postpartum. For women who don't breastfeed, or who combine nursing with using formula, levels of these hormones will change, meaning their period could return much sooner (as early as six weeks postpartum).
When your period returns, breast milk production is affected by the lower prolactin and increased estrogen levels. You can increase your milk supply by breastfeeding or pumping more frequently.
Prolactin and fertility
Exclusive breastfeeding or pumping often ensures high levels of prolactin. High prolactin levels prevent the ovaries from releasing eggs (ovulating), which in turn reduces your fertility. Moms who breastfeed exclusively or frequently pump milk in the first six months after birth are unlikely to have periods or get pregnant. As soon as you stop nursing or pumping regularly, your fertility will return.