Understanding Insulin Resistance in Perimenopause

# A Conversation with Pharmacist Aaron McDonough: Understanding Insulin Resistance and Its Impact on Your Health

By Online Health Coach, Sara Klute Behn, Your Wise Self with Sara

You’re doing everything you think you should. You’re eating reasonably, moving your body, and managing your stress as best you can. Yet, something has shifted. The weight is creeping up in places it never used to. Your energy crashes without warning. Your labs come back “normal,” and yet you feel anything but. If this sounds familiar, you’re not alone.

In my work as a lifestyle health coach supporting women in midlife, one of the most common root causes I see flying under the radar is insulin resistance. To help shed light on what’s really happening in your body—and what you can do about it—I sat down with Aaron McDonough, PharmD, functional health pharmacist and owner of Towncrest Pharmacy. What follows is a distillation of that conversation, offered with the same spirit that guides everything I do: helping you move from confusion to clarity, and from depletion to vitality.

What Is Insulin Resistance, Really?

When most people hear “insulin,” they immediately think of diabetes and assume it doesn’t apply to them. But according to Aaron, insulin resistance is “probably one of the biggest contributing root causes to several different chronic conditions”—including the hormonal shifts women experience in perimenopause.

Here’s how it works: Under normal circumstances, when you eat carbohydrates, your blood sugar rises, and your pancreas releases insulin. Insulin acts like a key, unlocking your cells to let glucose in for energy. Blood sugar then returns to normal.

When insulin resistance develops, the lock stops working as well. Your cells become overloaded with glucose—often from a carbohydrate-dense diet, inactivity, or chronic stress—and begin to resist insulin’s signal. Blood sugar stays elevated, your pancreas works harder to compensate, and you end up with both high blood sugar and high insulin. Over time, this takes a serious toll.

The goal is insulin sensitivity: your body efficiently using glucose for energy, with insulin cycling properly.

The Domino Effect: Why Insulin Resistance Affects Everything

What makes insulin resistance so impactful is the cascade of effects it triggers throughout the body. Three in particular are worth understanding.

1. The Stress Response

Your body interprets insulin resistance as a threat and activates your fight-or-flight response, releasing excess cortisol. The downstream effects of this are significant: increased fat storage (especially belly fat), reduced energy production, deteriorating sleep quality, and heightened anxiety. Sound familiar?

2. Chronic Low-Grade Inflammation

Unlike acute inflammation—which helps you heal when you get a scrape—chronic low-grade inflammation operates silently for years, even decades, before symptoms appear. As Aaron puts it: “It’s like 10 or even 20 years of unchecked, low-grade inflammation that we all of a sudden start recognizing.” Left unchecked, it can contribute to type 2 diabetes, cardiovascular disease, PCOS, thyroid imbalances, and elevated cholesterol.

3. Hormonal Imbalances

The relationship between insulin resistance and hormones is bidirectional—each affects the other, creating a challenging cycle that intensifies during perimenopause. This brings us to why this transition can feel so disorienting.

Why Perimenopause Makes Everything Harder

As we age, our bodies become less resilient. We have lower metabolic reserves, decades of exposure to environmental stressors, and the accumulated effects of our lifestyle choices. Then, hormonal decline begins—which is not a flaw, it’s biology. But when this natural transition happens alongside insulin resistance, symptoms intensify.

Estrogen decline leads to decreased skeletal muscle mass and increased fat storage. Progesterone changes disrupt sleep. Poor sleep perpetuates the cortisol–insulin resistance cycle. Belly fat accumulates. It can feel like everything is working against you at once.

Aaron says it plainly: “When you’re 15, you can eat a dozen donuts and it doesn’t affect you the way it does at 40. That’s because biochemically, physiologically, you are a different person.”

This isn’t a reflection of personal failure. It’s a physiological reality that deserves informed, compassionate support.

The Good News: Insulin Resistance Is Modifiable

Despite how overwhelming this may sound, insulin resistance is not a permanent condition. It responds to lifestyle changes—the kind of sustainable, personalized shifts that are at the heart of my THRIVE Method framework for supporting women through midlife transitions.

Movement

Consistency matters more than intensity. Daily movement is more powerful than one intense workout per week. Walking combined with resistance training is ideal—even something as simple as a 10-pound weighted vest during a daily walk can make a meaningful difference. The key is finding what feels sustainable for your body and your life.

Nutrition

There is no one-size-fits-all approach here. Your body has its own unique responses. Some practical starting points include:

• Choose low-glycemic, complex carbohydrates that provide steady energy rather than blood sugar spikes.

• Keep a food diary for one week to identify patterns and hidden triggers.

• Consider a continuous glucose monitor (CGM)—now available over-the-counter—to see exactly how specific foods affect your blood sugar in real time.

• Be curious about food sensitivities: even “healthy” foods can cause inflammation if your body doesn’t tolerate them well.

  
  

Sleep

Sleep is not a luxury—it’s a cornerstone of hormonal health. Even one alcoholic drink before bed can significantly reduce REM sleep. Avoiding caffeine in the evening, not eating right before bed, and tracking your sleep patterns are all meaningful places to start.

Stress Management

Chronic stress is one of the most underestimated drivers of insulin resistance. Supporting your neurotransmitter production (methylated B vitamins can help build serotonin and dopamine), addressing nutritional deficiencies, and building sustainable habits—small, consistent changes rather than dramatic overhauls—all reduce your body’s overall stress burden.

Strategic Supplementation

Working with a functional health professional to identify your specific nutritional needs can be a game-changer. Personalized supplementation addresses the underlying deficiencies that contribute to both insulin resistance and hormonal imbalances.

The Most Important Lab Test You’re Probably Not Getting

According to Aaron, the fasting insulin test is the most overlooked lab for detecting insulin resistance early—and it’s the one I consistently wish more of my clients had access to sooner. Standard tests like blood glucose and A1C often appear normal until insulin resistance is already advanced. Fasting insulin reveals problems years earlier, when intervention is most effective. Here are the ranges worth knowing:

• Fasting glucose (optimal): 70–90 mg/dL

• Fasting insulin (optimal): 2–6 μIU/mL

• Mild insulin resistance: 7–12 μIU/mL

• Higher concern: above 12 μIU/mL

  
  

Catching insulin resistance early—even in your 30s or early 40s—can prevent progression to chronic disease. Ask for this test at your next physical.

Why Lifestyle Medicine Is Hard (But Worth It)

Let’s be honest: lifestyle changes are hard. Results don’t happen overnight the way a prescription medication might appear to. It requires daily commitment in an environment that constantly pulls you toward old patterns. Social norms, stress, busy schedules—they’re all real.

But here’s what I’ve seen again and again with the women I work with: your brain adapts. As you build healthier habits, your body innately begins to support them. It gets easier. As Aaron says, “It’s usually a little of this, a little of that—and then we start getting some headway. Then we start feeling a little bit better.”

That momentum is real. And it’s available to you.

Key Takeaways

• Insulin resistance is a modifiable process, not a permanent condition.

• The perimenopause transition is inevitable, but how you experience it is not.

• Small, consistent changes in movement, nutrition, sleep, and stress management make a significant difference.

• Personalization matters—what works for one woman may not work for another.

• Early detection through fasting insulin testing can prevent progression to chronic disease.

• Professional support from health coaches and functional practitioners can accelerate your progress.

  
  

Your Next Steps

• Request a fasting insulin test at your next physical.

• Track your food intake for one week to identify patterns.

• Add daily movement that feels sustainable for your lifestyle.

• Consider a continuous glucose monitor to better understand your body’s responses.

• Seek professional support from practitioners who understand functional and lifestyle medicine, like Sara and Aaron.

  
  

You are not broken. Your body is responding to a complex interplay of hormones, lifestyle, and the natural process of aging. With the right information—and the right support—you can navigate this transition with confidence and vitality.

Want to learn more about personalized approaches to perimenopause health? Connect with Aaron McDonough at Towncrest Pharmacy for lab-informed supplementation and compounded hormone support. For comprehensive health coaching and lifestyle medicine guidance, explore Your Wise Self with Sara—Sara helps women navigate midlife with intention.

Listen to this conversation on the podcast Your Wise Self with Sara