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.
Dr. Jerilynn’s perspective adds important nuance to the discussion about progesterone and weight, especially around the physiological dose of oral micronized progesterone, the role of ovulation, and why many women notice increased appetite in the luteal phase without actual weight gain.
The Physiological Dose of Progesterone
Dr. Jerilynn notes: “It is important to say that 300 mg of oral micronized progesterone is the physiological dose.”
This matches the body’s natural luteal-phase production and is commonly studied for its effects on metabolism, sleep, and hot flashes.
No Weight Gain in a Randomized Controlled Trial
Dr. Jerilynn shared a strong reference: a randomized, double-blind, placebo-controlled trial published in PLOS ONE (2014) using 300 mg daily oral micronized progesterone for three months.
Key finding: No differences in body weight, BMI, or waist circumference between the progesterone and placebo groups.
This supports the idea that physiological-dose progesterone does not cause weight gain — complementing the dose-dependent data from my previous article.
Luteal Phase Energy Intake and the Invisible Calorie Burn
“My thought is that progesterone raises core temperature which requires increased energy. Therefore, there is a subtle increase in appetite that most women do not perceive. It is not insignificant at about 300 kcal. However, there is no weight change because that additional energy provides the elevated temperature.”
She referenced this prospective study (Barr SI et al., American Journal of Clinical Nutrition, 1996):
In ovulatory cycles (n=29): Energy intake increased significantly in the luteal phase (9,271 vs 8,012 kJ/d; P=0.001).
In anovulatory cycles: No significant change.
Recent Research on Appetite Across the Menstrual Cycle
Dr. Jerilynn also highlighted new work by Dr. Sarah Purcell and colleagues published in Appetite (2026).
Main findings: Energy intake and appetite were largely consistent across cycle phases, with a trend toward higher resting metabolic rate in the luteal phase.
Why This Matters for Progesterone and Weight
- Progesterone raises core temperature and energy needs in the luteal phase.
- This often triggers a subtle increase in appetite (~300 kcal).
- The extra calories support the temperature rise, so weight usually remains stable.
This explains why many women feel hungrier after ovulation without seeing the scale move, and why appropriate progesterone therapy rarely leads to weight gain in studies.
Thank you, Dr. Jerilynn
I’m grateful to Dr. Jerilynn C. Prior for sharing these insights. Her research continues to bring clarity to the complex relationship between progesterone, appetite, and weight.
Have you noticed changes in hunger or weight across your cycle or with progesterone? I’d love to hear in the comments.
References
Prior JC et al. PLOS ONE 2014. https://doi.org/10.1371/journal.pone.0084698
Barr SI et al. Am J Clin Nutr 1996;61:39-43.
Smith M et al. Appetite 2026;216:108314.
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