A few days after publishing my piece on progesterone and weight gain, I received a thoughtful email from Dr. Jerilynn C. Prior, MD, FRCPC, Professor Emerita of Medicine and a leading researcher in women’s reproductive health and menstrual cycle science. She kindly gave me permission to share her comments here.
Progesterone and Weight Gain: What the Dose-Dependent Data Actually Says
If you’ve recently started progesterone therapy—whether for menopause, IVF, perimenopause, or cycle regulation—you might have noticed a shift on the scale and asked yourself: does progesterone cause weight gain? The relationship between progesterone and weight gain is more nuanced than a simple “yes” or “no,” and the answer is highly dose-dependent.
🧠 A note from Carol
I’m a functional medicine practitioner, and I’ve spent years helping women separate hormone fact from hormone fiction. Here’s what surprises most of my new patients: the thing they’ve been blaming for their weight gain (progesterone) is often not the real problem at all. I wrote this article to give you the data — and a fresh perspective.
If something here resonates with your own experience, let’s talk.
👉 Book a 15-minute consult
Progesterone and Adrenaline: Calm vs. Fight or Flight
What comes to mind when you think of stress? For most of us, it’s adrenaline — the hormone that primes our body for “fight or flight,” increasing heart rate and sharpening our senses. But what counterbalances this powerful system? The answer, lies in an unexpected source: progesterone. This article explores the fascinating science of how progesterone and adrenaline interact, creating a dynamic interplay that affects mood, anxiety, and overall resilience.
What Is Sex Hormone–Binding Globulin (SHBG)?
Sex hormone–binding globulin (SHBG) is a protein made mainly in the liver. It binds strongly to key sex hormones like testosterone, dihydrotestosterone (DHT), and estradiol. By doing so, SHBG controls how much of these hormones stay “free” (unbound) and biologically active in the body. Think of SHBG as a gatekeeper: it influences how much hormone is available to tissues in both men and women.
5β-Reductase (AKR1D1): Hormone Off-Switch & Digestion Hero
Imagine your hormones as messengers racing through your body, delivering important signals. But what happens when they stick around too long? Enter 5β-reductase, a hardworking liver enzyme that acts like a gentle “off-switch,” calming down hormones like progesterone, testosterone, and cortisol while powering up the bile that helps you digest fats. This unsung hero keeps your hormone levels balanced and your digestion smooth—yet most people have never heard of it.[journals.plos]