When Does Perimenopause Start?
Perimenopause marks the transitional period before menopause, when a woman’s reproductive hormones begin to fluctuate. While many women associate menopause with their late 40s or 50s, perimenopause often starts much earlier than expected.
When Does Perimenopause Typically Begin?
According to the North American Menopause Society (NAMS), perimenopause can begin as early as a woman’s mid-to-late 30s, but most commonly starts in her early-to-mid 40s. The duration of perimenopause varies, lasting anywhere from 2 to 10 years before the onset of menopause.
What Triggers the Start of Perimenopause?
Perimenopause begins when the ovaries start producing less estrogen and progesterone, the hormones responsible for regulating the menstrual cycle. This hormonal shift is a natural part of aging but can be influenced by other factors, such as:
Genetics: The age your mother entered menopause can give you clues about your own timeline.
Lifestyle factors: Smoking, poor diet, and chronic stress may accelerate hormonal decline.
Medical interventions: Chemotherapy, radiation, or surgical removal of the ovaries can induce early perimenopause.
Science-Backed Early Signs of Perimenopause
While every woman’s experience is unique, research identifies the following common early symptoms:
Changes in Menstrual Cycle
Cycles may become shorter, longer, heavier, or more irregular.
Source: National Institute on Aging
Hot Flashes and Night Sweats
These vasomotor symptoms affect up to 75% of women during perimenopause.
Source: Journal of Women's Health, 2017
Sleep Disturbances
Hormonal fluctuations impact circadian rhythms and melatonin production.
Source: Sleep Medicine Clinics, 2018
Mood Changes and Irritability
Shifting estrogen levels affect serotonin, a key mood-regulating neurotransmitter.
Source: The Lancet Psychiatry, 2015
Decreased Fertility
Irregular ovulation reduces the chances of conception but doesn’t eliminate them.
Source: Mayo Clinic
Vaginal Dryness and Libido Changes
Thinning vaginal tissue and decreased lubrication are linked to estrogen decline.
Source: Journal of Clinical Endocrinology & Metabolism, 2013
How to Know If You’re in Perimenopause
There’s no single test to diagnose perimenopause, but your doctor may evaluate:
Menstrual history
Hormone levels (FSH, estradiol, etc.)
Symptoms journal
A combination of blood tests and symptom tracking often gives the clearest picture.
Take Action: What You Can Do Right Now
If you suspect you're entering perimenopause, here are 5 evidence-based steps you can take to support your health and manage symptoms:
Start a Hormonal Health Journal
Track cycle changes, sleep patterns, mood shifts, and any unusual symptoms daily or weekly.
Optimize Your Diet for Hormonal Balance
Focus on whole foods rich in fiber, omega-3s, and phytoestrogens (like flaxseeds and lentils).
Limit processed sugars and alcohol, which can worsen hormonal symptoms.
Incorporate Strength Training and Movement
Exercise helps regulate cortisol and support estrogen balance.
Aim for at least 3 days/week of resistance training and daily movement.
Consider Adaptogens and Supplements
Science-backed adaptogens like ashwagandha and maca may help stabilize mood and energy.
Always consult your healthcare provider before starting supplements.
Talk to a Perimenopause-Savvy Practitioner
Not all doctors are trained in hormone health. Seek out a menopause specialist or integrative practitioner if needed.
Why Early Awareness Matters
Identifying the start of perimenopause empowers you to:
Prepare for hormonal changes
Improve lifestyle habits that support hormonal balance
Explore natural or medical treatment options to reduce symptoms
Protect long-term health (including bone, brain, and cardiovascular health)
Final Thoughts
If you're in your late 30s or 40s and noticing unexpected changes in your body or emotions, perimenopause might be the reason. Understanding when perimenopause starts and how it affects your health is the first step to taking control of this natural transition.
