Can high prolactin stop your period?

Bottom lineYes - high prolactin is one of the most common and most treatable causes of periods stopping outside pregnancy. It suppresses kisspeptin and GnRH, so LH never surges and you do not ovulate, the same mechanism that pauses periods during breastfeeding. Levels of 20 to 50 ng/mL may only shorten the luteal phase, 50 to 100 make periods infrequent, and over 100 usually stops them entirely. If periods have stopped for three or more cycles and you are not pregnant, ask for prolactin and TSH; periods usually return within weeks to months once prolactin is normalized.

Yes. High prolactin is one of the most common causes of periods becoming irregular or stopping entirely outside of pregnancy, and it is one of the most treatable.

How it happens

High prolactin suppresses kisspeptin, a signal in the hypothalamus that drives GnRH release. Less GnRH means less LH, and without an LH surge you do not ovulate. No ovulation means no progesterone, and the cycle loses its structure.

It is the same mechanism that pauses periods during breastfeeding. Your body reads the prolactin signal as "we are feeding a baby," and puts reproduction on hold.

It depends on the level

• 20 to 50 ng/mL - cycles may look nearly normal, with only a shortened luteal phase
• 50 to 100 ng/mL - periods become infrequent or unpredictable
• Over 100 ng/mL - periods usually stop altogether

You may also have cycles where you bleed but never ovulate, which can disguise the problem.

What to do

If your periods have been irregular for several months or have stopped for three or more cycles and you are not pregnant, ask for a blood test that includes prolactin and TSH. Both are common, treatable causes, and both are cheap to check. See why your period stopped for the fuller list of causes.

The good news: when prolactin is brought back to normal, periods and ovulation usually return within weeks to a few months. More in prolactin in women.

Logging your cycles in Femora is the simplest way to show exactly how long your periods have been off.