Causes of Galactorrhea or Lactation

Have you noticed a milky discharge leaking from your nipple(s)? If you have and you are not pregnant or breastfeeding you are probably pretty upset.

Woman speaking with her doctor about breast health
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That is very understandable. Nipple discharge can be a sign of an underlying breast problem or other medical condition. If you are experiencing any type of nipple discharge you need to be evaluated by your healthcare provider.

Here are some facts you need to know about galactorrhea.


Galactorrhea is a nipple discharge composed of breast milk or a milk-like substance that is not associated with pregnancy or breastfeeding. This type of nipple discharge can come from only one nipple but it typically comes from both. It can flow spontaneously or just be noticed if you pinch the area around your nipple.

Galactorrhea occurs most commonly in women of reproductive age. And it is also more common in women who have been pregnant before. Although more common in early reproductive-age women, galactorrhea can occur in women of all ages, newborns and even in men.

If you are experiencing galactorrhea is it unlikely that it is a sign of breast cancer. That being said, it is still very important that you let your healthcare provider know about your symptoms.

The Influence of Prolactin

Galactorrhea results from abnormally elevated prolactin levels.

Prolactin is a hormone produced by the pituitary gland located at the base of your brain. The pituitary gland is part of the neuroendocrine system which works to regulate many of your bodily functions. Prolactin is normally present in small amounts that fluctuate daily.

One function of prolactin is to regulate your breast growth and development. Prolactin is also responsible for milk production or lactation after you give birth.

When you are not pregnant or breastfeeding, galactorrhea typically signals that you have an abnormally elevated prolactin level.

Elevated prolactin levels can inhibit the release of gonadotropin-releasing hormone (GnRH), the hormone that regulates your menstrual cycle. It is very common that if you have galactorrhea you may also have irregular periods. In fact, if you have galactorrhea you may not be getting your period at all, a condition known as amenorrhea.

Medications That Can Cause Galactorrhea

Galactorrhea is very often caused by certain types of medications that affect your body’s prolactin balance. These medications either interfere with dopamine, the hormone that inhibits prolactin release, or they directly stimulate the pituitary gland to produce prolactin. Types of medications that can cause galactorrhea include:

  • Antipsychotics
  • Antidepressants
  • Antihypertensives
  • Oral contraceptives
  • Opioids

If you are on one of these classes of medication and you develop galactorrhea it is likely that the medication is the cause. Be sure to see your healthcare provider discuss this. Do not stop taking any medication without first discussing it with your healthcare provider.

In addition to medication, certain herbal supplements can cause galactorrhea including:

Pituitary Tumor

The pituitary gland is located at the base of your brain. It is part of your body’s neuroendocrine system. It produces prolactin, the hormone responsible for milk production in lactating women. Tumors that arise in the pituitary gland resulting in elevated levels of prolactin, a condition known as hyperprolactinemia. Elevated levels of prolactin due to a pituitary tumor will cause galactorrhea and amenorrhea or no menstrual periods. Because of the location of the pituitary gland, if the tumor is large enough it can also cause headaches and visual symptoms.


Leaking milk from your breasts is probably one of the last things you would want to discover if you are already under a lot of stress. But believe it or not chronic stress can cause galactorrhea. Wondering how that happens? You guessed it. Chronic stress causes changes in your body that can result in increased levels of prolactin the lactation hormone.

Breast Stimulation

If chronic stress can cause increases in your prolactin levels, it isn’t hard to image that breast stimulation can do the same. Repetitive and intense nipple stimulation even when you are not pregnant or breastfeeding can trigger hormonal changes that result in elevated prolactin levels and galactorrhea.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Practice bulletin no. 164: diagnosis and management of benign breast disorders. Obstet Gynecol. 2016;127(6):e141-e156. doi:10.1097/AOG.0000000000001482

  2. American Academy of Family Physicians. Galactorrhea.

  3. Patrascu OM, Chopra D, Dwivedi S. Galactorrhoea: report of two cases. Maedica (Bucur). 2015;10(2):136-139. PMID: 28275406

  4. National Institute of Diabetes and Digestive and Kidney Diseases. Prolactinoma.

  5. Levine S, Muneyyirci-Delale O. Stress-induced hyperprolactinemia: pathophysiology and clinical approach. Obstet Gynecol Int. 2018;2018:1-6. doi:10.1155/2018/9253083

By Tracee Cornforth
Tracee Cornforth is a freelance writer who covers menstruation, menstrual disorders, and other women's health issues.