When Does Perimenopause Start (and What Are the Symptoms)?

Perimenopause rarely gets the spotlight it deserves. Especially since it’s one of the biggest hormonal changes someone will go through, and affects roughly half the population. Need an introduction to the topic? We can help. What is it, when does perimenopause start, and what are the symptoms? Read on to learn more.

Perimenopause is the transitional period between your prime fertile years and menopause (which marks the end of your fertile years). During this time, your body is preparing for its grand finale of egg production. (Quick reminder: you’re born with all the eggs you’ll ever have and they deplete over time. Perimenopause indicates you’re getting close to the end of your viable eggs.) During perimenopause, your hormones fluctuate a lot more than usual, resulting in symptoms (more on that in a sec) that are often referred to as a rollercoaster.

Perimenopause typically kicks off in your 40s, though it can start younger—some may start seeing perimenopause symptoms as early as 37. There’s no crystal ball—we can’t tell you exactly when you’ll start menopause, but clinical factors (like menstrual patterns, symptom changes, and family history) can help with an educated guess. These indicators provide context rather than certainty, and (along with your overall health picture) can provide some insight. If you’ve been diagnosed with diminished ovarian reserve (DOR), you’ll likely begin to experience symptoms sooner than the 40-ish guideline.

For most, perimenopause will last about 4 to 8 years, but it can be longer (or shorter!). Since it’s a transition period, the start is often marked by a wide range of symptoms instead of an official clinical diagnosis (though you can get one). Perimenopause is considered over when you enter menopause (which is when you’ve gone 12 consecutive months without a period), but unfortunately, the symptoms don’t typically stop right away when you graduate to menopause. 

You may be experiencing perimenopause symptoms, but that doesn’t mean you’re infertile, though it can make it harder to get pregnant. You still do have viable eggs, you just have fewer, and they’re being ovulated more sporadically. Plus, some of the symptoms of perimenopause, like changing cycle lengths and unpredictable ovulation, add to the list of things that can affect your ability to get pregnant. Getting pregnant in perimenopause is not impossible, but you’ll likely want to seek out the help of a clinic and get started right away if growing your family is a goal during this time.

And if you’re not trying to get pregnant? Keep using contraceptives—preventing pregnancy is also necessary during this time.

In medicine, the stages of reproductive health aging are defined by the STRAW (stages of reproductive aging workshop) criteria. The STRAW system is a research-based framework, originally developed in 2001, and used to describe the natural stages leading up to menopause, including perimenopause. It was developed by international menopause and reproductive health experts and later updated in 2011 (called STRAW+10) to reflect newer and updated guidelines. Today, it’s widely used in research and clinical care to help make sense of menstrual and hormonal changes, but it’s meant to guide understanding—not to predict exact timelines for any one person. 

• Late reproductive: Relatively regular cycles, normal to variable FSH, low ovarian reserve

• Early perimenopause: Variable cycles and FSH, low ovarian reserve

• Late perimenopause: Cycles are greater than 60 days apart, FSH high, low ovarian reserve

• Menopause: Menses have ended (more than 12 months without a period), FSH high, ovarian reserve low or undetectable

Not everyone will get a medical perimenopause diagnosis, so there are other ways to gain insight into your reproductive timeline. Everyone experiences perimenopause differently; it’s like a hormonal fingerprint that’s uniquely yours. Some might breeze through without so much as a hot flash, while others may feel that this transition completely upends their quality of life. But, symptoms are quite common—90% of perimenopausal people ask their healthcare providers for symptom support. 

Although perimenopause does include changes to your cycle, the earliest symptoms are often other changes.

Because these symptoms can often be linked to other health concerns, if you’re under 45, your doctor will want to rule out those other potential health issues before confirming perimenopause. Ultimately, perimenopause is diagnosed clinically, so if you’re chatting with a healthcare professional, they’ll likely ask you about a few things before making the diagnosis.

It’s a good idea to know or keep track of:

• Symptoms

• Cycle history

• Past medical history

• Family history

Perimenopause is a crucial time to not only address symptoms, but also to think about your long-term health and maintaining or improving it with habits.

In perimenopause, estrogen declines, which can have some big impacts on your overall health, including cardiovascular health, bone density, cognitive health, and more. As estrogen declines, it’s a good idea to support these areas with other health foundations (often including lifestyle, medical, and supplement support).

If you suspect you might be perimenopausal (or if you’re at an age where it could happen soon), there are some changes you can make (or continue to do) today to support your overall health and lay the foundation for a smoother menopausal experience.

1. Eat a Mediterranean diet

A diet high in protein, fruits and vegetables, healthy fats, plenty of fish, and low in processed foods supports your hormonal health, can reduce caloric intake overall, and can help you avoid weight gain.

2. Get enough exercise

Getting a minimum of 150 minutes per week of physical activity is key to preventing lean-tissue loss and osteoporosis. Strength training and mobility exercises are particularly recommended to prevent muscle loss and joint pain.

3. Limit alcohol and caffeine

Especially in the two weeks before your expected period, limiting alcohol and caffeine is recommended. Both can make symptoms worse, even in small amounts (sorry!).

4. Prioritize sleep and stress management

Your mental health is important, and your body and mind need sleep to work properly—make sure you have good sleep and mental health habits set up before the perimenopausal shifts affect both

5. Track your cycles

Knowing more about your reproductive health helps you note changes and communicate them with a healthcare professional when it’s time to seek out more support.

• Omega-3: DHA (625 mg) alone or DHA (1 g) and EPA (240 mg) have shown improvements in mood and cognitive function.

• Creatine: May improve cognitive function and fatigue, as well as the effectiveness of antidepressants at 3 g per day.

• Vitamin D: Supports blood levels to help prevent bone density loss.

• Calcium: Aim for 1,200 mg per day (from both diet and supplemental sources) to help prevent bone density loss.

• Phytoestrogens: (like soy): With continuous use at 25 g per day, soy protein may reduce blood pressure, support bone density, and improve hot flashes for some patients.

• Hormone therapy: Hormone replacement therapy (or MHT—menopausal hormone therapy) is the gold standard for supporting the symptoms of perimenopause. It’s effective, but also requires close monitoring, reevaluation, and readjustment because of the significant hormonal changes happening over this time.

• Contraception: Yes, you read that right. While it still can be used as a way to prevent pregnancy (if you’re still ovulating), it also helps manage symptoms of perimenopause like heavy bleeding, menstrual-related migraines, and other hot flashes or night sweats.

• CBT (cognitive behavioural therapy): Though it’s most known for its mental-health benefits, CBT-I can also improve insomnia in perimenopause.

Perimenopause and menopause are natural parts of life's journey. They might come with some challenges, but they also bring opportunities for growth, self-discovery, and maybe even a newfound appreciation for your amazing body. Remember, there's no one-size-fits-all approach to managing this transition; what works for your bestie might not work for you, and that's totally okay. 

Embrace the change, seek support when you need it, and don't be afraid to advocate for yourself. After all, you're not just going through perimenopause—you're growing through it, too, and the choices you make now can help support your health for decades to come.