Perimenopause in Your Late 30s: What’s Changing and How to Support Your Body

What is perimenopause?

Perimenopause is the transitional phase before menopause when the ovaries gradually produce less estrogen and progesterone. This process can begin in your 30s or 40s and often lasts several years. Hormone levels can fluctuate — sometimes dramatically — which is why symptoms can feel unpredictable.

Common early symptoms in your late 30s

Even if your cycles still look “normal,” you may notice early signs of perimenopause. Typical symptoms include:

• Changes in menstrual cycles — shorter, longer, heavier, or lighter periods
• Mood swings, increased irritability, or low mood
• Fatigue and difficulty sleeping (trouble falling asleep or staying asleep)
• Lowered libido
• Breast tenderness, bloating, or mild pelvic discomfort
• Occasional hot flashes or night sweats
• “Brain fog” — memory lapses or reduced mental clarity
• Weight redistribution or difficulty losing weight

If symptoms are new, persistent, or severe, check in with your healthcare provider — many symptoms overlap with other common conditions (thyroid issues, stress, sleep disorders, etc.).

How many eggs are left in your late 30s?

Women are born with the full pool of eggs they’ll ever have. While exact numbers vary widely between individuals, a general pattern is:

• At birth: roughly 1–2 million primordial follicles (eggs)
• At puberty: about 300,000–400,000 remain
• By the late 30s: the ovarian reserve drops substantially — many estimates put the remaining count in the tens of thousands (commonly cited figures like ~25,000 at age 37 are approximations and individual variation is large).

Importantly, both the quantity and the quality of eggs decline with age, which is why ovulation can become irregular and hormone patterns shift during perimenopause.

How to support your body during perimenopause

There are many practical, evidence-informed ways to support hormone balance and overall wellbeing as your body transitions:

1. Nutrition that stabilizes hormones

• Prioritize high-quality protein at each meal to help steady blood sugar and support hormone production.
• Include healthy fats (olive oil, avocado, nuts, seeds) — fats are building blocks for hormones.
• Eat plenty of fiber and colorful vegetables to assist liver detoxification and estrogen metabolism (cruciferous vegetables can be especially helpful).
• Limit processed sugars and refined carbs that exacerbate mood swings and energy crashes.

2. Sleep & stress management

• Prioritize consistent sleep habits — regular bed and wake times, a wind-down routine, and sleep-friendly habits (low screens before bed) help balance hormones.
• Daily stress-reduction practices (breathing, gentle yoga, short walks, mindfulness) reduce cortisol-driven hormone disruption.

3. Movement & strength

• Resistance training supports bone health and metabolic rate; regular cardio and walking support mood and sleep.
• Choose activities you enjoy — consistency beats intensity.

4. Lifestyle tweaks

• Reduce or moderate caffeine and alcohol if they worsen sleep, hot flashes, or anxiety.
• Stay hydrated and prioritize regular hormone checks (thyroid function, metabolic health, etc.).

Why hormone testing matters — and how to do it easily

Because perimenopause looks different for every woman, routine hormone testing can be a powerful way to understand what your body needs. Testing helps you:

• See where estrogen, progesterone, testosterone, thyroid hormones, and sometimes adrenal hormones are trending
• Track changes over time rather than guessing only based on symptoms
• Guide targeted lifestyle changes, supplements, or conversations with your clinician

To make this simple and discreet, Nourish & Cleanse with Heather Martin offers an at-home hormone lab test that lets you collect samples at home and send them to a partnered laboratory for analysis. Regular testing (frequency depends on your goals — many people check annually or when symptoms change) helps you stay proactive and informed.

Takeaway

Perimenopause can begin in your late 30s and present with subtle but impactful symptoms. You don’t have to navigate it blindly — nutrition, sleep, movement, and stress management all help, and regular hormone testing gives you data to make confident choices for your health.