How early can perimenopause start?
Short answer
Perimenopause most often starts in a woman's mid-to-late 40s, but it can begin in the late 30s.
If your cycle changes in your 30s, it is worth checking with a doctor, since menopause before 40 is premature.
What is a typical age to start?
Most women notice the first changes in their mid-to-late 40s, a few years before the average age of menopause, which is around 51 in the United States. A start in the late 30s or early 40s is not unusual.
The first sign is often a shift in your cycle: periods a little shorter, longer, heavier or lighter than before. Other symptoms such as poor sleep, mood changes or hot flashes can show up too.
Can perimenopause start in your 30s?
Yes, it can, though it is less common. Some women see changes in the late 30s. Because other things also cause irregular periods in this age group, it is worth getting checked rather than assuming.
Possible reasons for a cycle that changes early include thyroid conditions, polycystic ovary syndrome, high stress, big weight changes, and certain medications.
What makes it more likely to start early?
- Family history: the age your mother or sisters reached menopause is a strong clue.
- Smoking: it is linked with menopause arriving earlier.
- Medical treatment: chemotherapy, pelvic radiation or ovary surgery can bring it on sooner.
- Some health conditions: certain autoimmune and genetic conditions are associated with earlier ovarian aging.
Menopause before 40 is called premature ovarian insufficiency. It is worth a medical evaluation, because it affects bone and heart health over the long term, and treatment options exist.
If you recognize early signs and want to look into support, a perimenopause supplement is one option some women explore alongside a doctor's guidance. Research on botanicals is mixed, so it should not stand in for a proper check of what is going on.
Cycle length is the easiest thing to track. Note the first day of each period in your phone, and look for a gap that keeps shifting by a week or more. That pattern, more than any single symptom, is what points to the transition starting.
Talk to a doctor if your periods change noticeably before 40, stop for several months, or come with very heavy bleeding.
Sources
- STRAW+10, Harlow SD et al., 2012: staging of the menopausal transition, including typical timing.
- National Institute on Aging (NIH), menopause pages: when the transition usually begins and what can bring it on earlier.
- ACOG, patient resources on early and premature menopause: definitions and causes.
Related questions
The first sign of perimenopause is usually a change in your period: shorter, longer, heavier or skipped. Poor sleep, hot flashes, mood changes and brain fog often show up alongside it.
No single test can confirm perimenopause, because hormone levels swing from day to day. Doctors diagnose it from your age, symptoms and period changes, using tests mainly to rule out other causes.
Perimenopause is the transition leading up to menopause; menopause is 12 months in a row without a period. Everything after that is postmenopause. Pregnancy is only possible before menopause.