Your Hormones After 40: The Changes No One Talks About (But Should)

Beyond Hot Flashes: The Full Spectrum of Perimenopausal and Menopausal Changes

“Why am I so foggy?”
“Where did this belly come from?”
“Why can’t I sleep through the night anymore?”

If you’ve asked yourself these questions after turning 40, you’re likely experiencing perimenopause — the transitional phase leading to menopause that can begin as early as your late 30s or early 40s. While hot flashes and irregular periods get plenty of attention, they’re merely the tip of the iceberg when it comes to the profound perimenopausal and menopausal changes happening in your body.

The truth is, perimenopause and menopause affect virtually every system in your body — from your brain to your gut, your metabolism to your mood. Most women will spend a third of their lives in perimenopause and post-menopausal stages, yet many navigate this terrain with minimal information, chalking up their symptoms to “just getting older” or “being stressed.”

At Richmond Integrative & Functional Medicine, we believe knowledge is power. Understanding what’s happening in your body is the first step toward reclaiming your energy, mental clarity, and overall well-being during this transformative time.

The Perimenopause Timeline: Understanding How Hormones Change

Perimenopause typically begins in your 40s (though sometimes earlier) and lasts until menopause — defined as 12 consecutive months without a period. During this transition, your reproductive hormones don’t all decline at the same rate or time. This creates a cascade of perimenopausal changes that unfolds over years — not months.

Understanding these changes requires looking at hormones in the proper context. As outlined in our comprehensive guide to the hormone hierarchy, it’s important to address primary hormones like cortisol, insulin, and thyroid before focusing on sex hormones, as these foundational hormones significantly impact how your body processes estrogen, progesterone, and testosterone.

Progesterone: The First to Fall

Many women don’t realize that progesterone — not estrogen — is typically the first hormone to decline, often beginning in your early 40s or even late 30s. Progesterone, often called “the elder sister”, plays crucial roles beyond reproduction, including promoting quality sleep, lowering cortisol, and supporting bone strength.

This early progesterone drop creates an imbalance where estrogen becomes relatively dominant, even though your absolute estrogen levels haven’t yet decreased significantly.

This relative estrogen dominance can cause:

• Heavier periods
• Breast tenderness
• Mood swings
• Sleep disturbances
• Water retention

The Estrogen Roller Coaster

As perimenopause progresses (usually in your mid-to-late 40s), estrogen levels begin to fluctuate dramatically — sometimes soaring higher than they were in your younger years, then plummeting to very low levels. This roller coaster — rather than the absolute levels of estrogen — is responsible for many perimenopausal symptoms.

Estrogen, “the younger sister,” has over 400 critical functions in the body, affecting everything from brain function and bone density to heart health and skin smoothness. Understanding these extensive roles helps explain why estrogen fluctuations create such wide-ranging symptoms.

During this phase, you might experience:

• Hot flashes and night sweats (during estrogen dips)
• Anxiety and irritability (during estrogen peaks)
• Irregular periods
• Heart palpitations
• Vaginal dryness (which may come and go)

Testosterone’s Subtle Shift

While testosterone is often thought of as a “male hormone,” it plays vital roles in women’s health too. Testosterone in women supports muscle mass, bone strength, memory function, mental health, and energy levels — functions that become increasingly important as we age.

Women’s testosterone levels decline about 50 percent between ages 20–40 and continue to decrease gradually through the perimenopausal transition.

Lower testosterone contributes to:

• Decreased muscle mass
• Lower energy levels
• Reduced sexual desire
• Thinning skin and hair
• Challenges maintaining bone density

The Brain–Hormone Connection: Cognitive Changes Explained

One of the most distressing—yet least discussed—aspects of the perimenopausal transition is the change in cognitive function that many women experience. The phenomenon commonly called “brain fog” is very real and has a physiological basis.

Recent research confirms what many women report—perimenopause affects cognition in measurable ways. Studies show that verbal learning and memory are most commonly affected, with difficulties emerging during perimenopause when menstrual cycles become irregular. These changes aren’t just subjective feelings—they’ve been documented in multiple clinical studies.

What’s Happening in Your Brain?

Your brain is rich in estrogen receptors, particularly in areas responsible for memory, attention, and mood regulation. When estrogen levels fluctuate and eventually decline, these brain regions can’t function as efficiently.

Additionally, estrogen influences neurotransmitters such as serotonin, dopamine, and acetylcholine, which are critical for cognitive function and mood stability. Fluctuations in these chemicals during perimenopause contribute to:

• Word-finding difficulties
• Challenges concentrating
• Problems with working memory
• Mental fatigue
• Difficulties multitasking

The Good News

For most women, these cognitive changes are temporary—not progressive. Research indicates that the brain eventually adapts to lower hormone levels once the menopausal transition is complete. Many women report their cognition improves post-menopause, though it may not return entirely to pre-menopausal levels.

Supporting Your Brain Through the Transition

• Prioritize sleep
• Regular exercise
• Cognitive training
• Anti-inflammatory diet
• Stress management

The Metabolic Shift: Why Your Body Processes Food Differently

If you’ve noticed that the eating habits that kept you fit in your 30s are no longer working, you’re not imagining things. The hormonal changes of perimenopause significantly impact metabolism, making it easier to gain weight and harder to lose it—particularly around your midsection.

The Estrogen–Insulin Connection

Estrogen plays a crucial role in regulating insulin sensitivity. As estrogen declines, many women become more insulin-resistant, meaning the body must produce more insulin to manage blood sugar effectively. Higher insulin levels lead to:

• Increased abdominal fat storage
• Greater difficulty utilizing stored fat for energy
• Stronger carbohydrate cravings
• Energy dips throughout the day
• Heightened risk of metabolic syndrome

Muscle Mass Matters

The decline in estrogen and testosterone contributes to a gradual loss of muscle mass. Because muscle tissue burns more calories than fat tissue, losing muscle further slows metabolism. On average, women lose about 3–8 percent of muscle mass per decade after age 30, with the rate accelerating after menopause. This loss affects resting metabolic rate, strength, insulin sensitivity, bone density, and energy levels.

Addressing the Metabolic Shift

• Prioritize protein
• Strength training
• Consider meal timing
• Monitor carbohydrate intake
• Ensure adequate sleep

The Gut–Hormone Connection: A Two-Way Street

The Estrobolome: Your Hormone-Processing Microbes

• Liver processes estrogen ? intestines
• Estrobolome bacteria reactivate estrogen
• Estrogen reabsorbed into circulation
• Overall estrogen levels affected

How Hormonal Changes Impact Gut Health

• Decreased digestive-enzyme production
• Slower gut motility
• Increased intestinal permeability
• Reduced microbiome diversity

Supporting Your Gut Through Hormonal Transitions

• Prioritize fiber
• Include fermented foods
• Consider phytoestrogens
• Minimize inflammatory triggers
• Stay hydrated

Hormone Replacement Therapy: Weighing the Options

The Timing Matters

Starting HRT within 10 years of menopause may:

• Manage vasomotor symptoms
• Support bone health
• Help cognitive function
• Offer cardiovascular benefits
• Improve quality of life

Bioidentical vs. Synthetic

• FDA-approved bioidenticals are tested
• Compounded hormones lack consistency
• Delivery method may matter more

Delivery Methods

• Transdermal ? safer for clot/stroke risk
• Oral ? increases clot risk
• Vaginal ? local relief, minimal systemic effect
• Micronized progesterone often safer than synthetic

The Personalized Approach

Best practice depends on symptoms, medical history, age, time since menopause, preferences, lifestyle, and ongoing monitoring.

The Functional Medicine Approach: Beyond HRT

Comprehensive Testing

A functional-medicine approach evaluates:

• Complete hormone panel
• Full thyroid work-up
• Metabolic markers
• Nutrient status
• Gut-health evaluation

Addressing the Hormone Hierarchy

Steps are followed in this order:

1. Cortisol
2. Insulin
3. Thyroid
4. Sex hormones

Supportive Supplements and Botanicals

• Adaptogens
• Black cohosh
• Maca root
• Omega-3 fatty acids
• Magnesium
• Vitamin D

Detoxification Support

• Cruciferous vegetables
• Antioxidants
• Adequate hydration
• Reduced toxin exposure

Lifestyle Medicine for Hormonal Transition

Nutrition Strategies

• Anti-inflammatory focus
• Blood-sugar stability
• Phytoestrogen-rich foods
• Calcium & vitamin D
• Mindful alcohol consumption

Movement Approaches

• Strength training
• Zone 2 cardio
• Flexibility & mobility work
• Mind–body practices
• Adequate recovery

Sleep Optimization

• Consistent schedule
• Cool bedroom temperature
• Calming bedtime ritual
• Light management
• Sleep-supporting nutrients

Stress Transformation

• Mindfulness practices
• Cognitive reframing
• Nature exposure
• Social connection
• Pleasure and play

Looking Forward: Thriving Through Perimenopause & Menopause

A Time for Recalibration

• Connect with your body
• Let go of unhelpful habits
• Explore new purpose
• Prioritize preventive care
• Embrace self-compassion

Long-term Health Considerations

Changes in estrogen, progesterone, and testosterone can affect:

• Cardiovascular health
• Bone density
• Metabolic function
• Brain health
• Immune function

Your Action Plan: Next Steps

1. Assess your current status—obtain comprehensive testing.
2. Identify priorities—focus on the symptoms that impact you most.
3. Implement foundational changes—start with cortisol, insulin, thyroid.
4. Consider targeted therapies—both conventional and functional.
5. Monitor and adjust—repeat labs and tweak as needed.

Finding Support

• Work with informed providers
• Connect with peers
• Use science-based resources
• Advocate for root-cause care

Conclusion: Navigating Perimenopause & Menopause with Confidence

Perimenopause and menopause are significant life transitions, but they need not be a crisis. With understanding, support, and strategic interventions, these natural phases can catalyze renewed vitality and purpose.

Richmond Integrative & Functional Medicine is committed to empowering women throughout this journey. If you’re experiencing perimenopausal or menopausal symptoms and want personalized support, schedule a consultation with one of our providers.

Frequently Asked Questions About Perimenopause & Menopause

What are the early signs of perimenopause?

Irregular periods, increased PMS, sleep problems, mood shifts, hot flashes, brain fog, fatigue, and libido changes.

How long does perimenopause last?

Typically 4–8 years, though it can range from 2–10 years depending on the individual.

What is the average age for perimenopause to start?

Usually mid-40s—but it can start in late 30s or early 50s, influenced by genetics and health factors.

What’s the difference between perimenopause and menopause?

Perimenopause = the transition.
Menopause = one year after your last period.

Can you get pregnant during perimenopause?

Yes—until you’ve gone 12 months without a period, pregnancy is still possible.

What are the best treatments for perimenopausal symptoms?

The most effective strategy follows the hormone hierarchy: address cortisol, insulin, and thyroid first, then use targeted interventions (lifestyle change, bioidentical HRT, non-hormonal meds, supplements) tailored to your unique profile.