1. Health

Follicular Phase of the Menstrual Cycle


Updated June 03, 2014

Hand circling calendar date with pen
Jupiterimages/Photolibrary/Getty Images
Definition: Follicular Phase: The follicular phase begins on Day 1 of your menstrual cycle. Day 1 is by definition the day your period starts. The follicular phase ends when a hormone called luteinizing hormone peaks and ovulation occurs.

In the early follicular phase, after menstrual flow has ended, the lining of the uterus is at its most thin. Levels of estrogen and progesterone are at their lowest. Later in the follicular phase, proliferation (or thickening) of the uterine lining occurs. This thickened lining is preparing for a possible pregnancy. The follicular phase typically lasts about 14 days. The luteal phase begins when the follicular phase ends.

Also Known As: proliferative phase
The female hormones estrogen and progesterone are at their lowest levels during the early follicular phase of the menstrual cycle.
  1. About.com
  2. Health
  3. Women's Health
  4. Women's Health Glossary
  5. Definition: Follicular Phase of the Menstrual Cycle

©2014 About.com. All rights reserved.

We comply with the HONcode standard
for trustworthy health
information: verify here.