8 Changes in Your Menstrual Cycle During Perimenopause—Usually After Age 40

Period frequency, flow, and PMS can change as hormones shift.

Perhaps from the very first day you got your period, you've been able to count on it coming back month after month (except during pregnancy) for nearly four decades. You'll probably be dealing with it until you reach menopause, which happens around age 52 on average. And after you turn 40? That's when your body starts to shake things up. Whether you're approaching 40 or want to know what can happen to your flow after you do, here's what OB-GYNs said to expect.

Despite its inevitability, your period won't always operate the exact same way the longer you have it. You will experience changes in your menstrual cycle throughout the decades, especially since your period is directly tied to your hormones.


Before you reach menopause, your body goes through perimenopause. Perimenopause is a transition time before full menopause. It is defined as 12 straight months without a period. Perimenopause can last about seven years on average.

Most women will start perimenopause in their early 40s, but it can begin earlier. During this time, you may notice changes in your menstrual cycle.

Less Frequent Periods

"Perimenopause is a time that's characterized by irregular menses, which are usually more spaced out," said Rebecca Dunsmoor-Su, MD, an ob-gyn in Seattle. As your hormones start to fluctuate, "it can lead to scanter, lighter periods," added Adeeti Gupta, MD, an ob-gyn and founder of Walk In GYN Care in New York City.

You Might Start Skipping It Here and There

Don't worry—or get too excited—if your period goes entirely missing one month. "Some months, the eggs just don't reach a point where they release, and so a period gets missed," said Dr. Dunsmoor-Su. Remember: You're not in menopause until you go an entire year without a period, so skipping a month doesn't necessarily mean you can toss all your pads and tampons.

Your Periods Can Come Closer Together

Because there's no "normal" when it comes to your menstrual cycle, some individuals might experience more periods during perimenopause. In some cases, "estrogen and progesterone surges during the menstrual cycle become shorter and higher," said Dr. Gupta. "That means your periods could come closer together."

Your Flow Might Get Heavier

As your ovaries start their pre-menopause wind-down, your period schedule will be off track, which could possibly lead to a change in flow.

"Some months, the egg makes it to release on time, and everything's fine," said Dr. Dunsmoor-Su. "Some months, it's a bit behind, and your period will be late, and some months, it doesn't make it at all, and you skip a month or two. When you miss ovulation, the lining of the uterus continues to grow so that when you finally bleed, it tends to be heavier."

Of note, other conditions can cause heavy menstrual bleeding, like polycystic ovary syndrome (PCOS) or hypothyroidism. If you find that you are experiencing significantly heavy bleeding during your period, you'll want to talk to a healthcare provider.

Your PMS Can Feel Even Worse

All those hormonal ups and downs that start after 40 can affect your mood and emotions before your period begins.

"As the hormones fluctuate more dramatically, those women who have mood symptoms with their periods tend to see more fluctuations in those moods," said Dr. Dunsmoor-Su. "Some women get very depressed as the hormonal fluctuations become more significant."

If you are becoming significantly depressed, don't hesitate to reach out to a healthcare provider "Anti-depressants are very helpful in this kind of depression, and if left untreated, it can become very severe during the menopausal transition," Dr. Dunsmoor-Su said.

Your Cramps Could Become More Painful

Even though your periods might come less frequently or be lighter than before, you'll still likely experience those gut-churning cramps—and they might be worse.

"Cramps can get worse in the beginning of perimenopause due to the closer and stronger surges of estrogen and progesterone," said Dr. Gupta. The good news, however, is that as you close in on menopause, your flow shows up less often and is lighter—hence, fewer cramps, Dr. Gupta said.

You're Less Fertile, but Can Still Get Pregnant

Your chances of getting pregnant decrease as you move through your 40s due to a decrease in egg quality alongside any other health issues or lifestyle factors (e.g., smoking, stress) you might have.

But you can get pregnant in this decade, said Dr. Dunsmoor-Su. This is because ovulation can still happen: "There is an ovulation (egg release) 14 days before each period as long as you have your period," explained Dr. Dunsmoor-Su.

Using birth control may be an option if you don't want to get pregnant in your 40s. In fact, 74.8% of individuals between the ages of 40 and 49 were using birth control from 2017 to 2019. But you'll want to talk with a healthcare provider first to determine what type of birth control may be the best option for you.

You Might Start Breaking Out Before Your Period

It's also possible to experience what's called adult acne in your 30s, 40s, or 50s. A number of things can be a factor in adult acne, including:

  • Stress
  • Hair or skin care products
  • Medication side effects
  • Pregnancy
  • Undiagnosed medical conditions

However, adult acne can also happen due to hormone fluctuations caused by periods, perimenopause, or birth control. So, once you hit 40, "it's like going through puberty again," said Dr. Gupta, who warns you might start breaking out again just like in high school.

What Else To Consider About Menstrual Cycle Changes After 40

Along with the changes above, you might also begin to get hot flashes and night sweats during perimenopause, but these symptoms tend to come and go as hormones fluctuate, said Dr. Dunsmoor-Su.

Although changes in your cycle over time are normal, they could signal abnormalities—and sometimes, it's hard to tell the difference. Still, don't immediately assume the worst if you experience one month of period irregularities.

However, "if you have significant sudden changes in your cycle, you should see an ob-gyn for evaluation for possible structural causes (like fibroids or polyps) or pre-cancer syndromes," suggested Dr. Dunsmoor-Su.

A Quick Review

You can expect to experience changes with your menstrual as you get older. In your 40s, those changes might include irregular periods, heavier menstrual flow, and acne breakouts. However, you'll want to pay attention to any significant changes in your period that seem to be out of the ordinary. You'll want to consult a healthcare provider for those concerns.

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Health.com 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. Office on Women's Health. Menopause basics.

  2. Office on Women's Health. Your menstrual cycle.

  3. National Institute on Aging. What is menopause?

  4. Office on Women's Health. Menopause symptoms and relief.

  5. The American College of Obstetricians and Gynecologists. Heavy menstrual bleeding.

  6. Office on Women's Health. Trying to conceive.

  7. Centers for Disease Control and Prevention. Current contraceptive status among women aged 15-49: United States, 2017-2019.

  8. American Academy of Dermatology. Adult acne.

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