Liraglutide increases leptin gene methylation in ovarian cells of obese PCOS patients, linking epigenetics to fertility | Research

The takeaway

In 135 obese PCOS patients, liraglutide increased leptin promoter methylation in ovarian granulosa cells, decreased leptin levels, and improved sex hormones—revealing an epigenetic mechanism for GLP-1 drug fertility benefits.

Epigenetic ovarian changes
Liraglutide increased leptin gene methylation in ovarian granulosa cells—one of the first demonstrations of GLP-1 drug epigenetic effects on reproductive cells

What the researchers found

Obese PCOS: elevated BMI, insulin, glucose, HOMA-IR, testosterone, estradiol; reduced LEP promoter methylation. Liraglutide: ↑LEP promoter methylation → ↓leptin levels → altered sex hormones. Weight/fat loss observed. 135 obese + 72 non-obese PCOS patients.

Why it matters

Leptin dysregulation impairs ovarian function in PCOS. Discovering that liraglutide epigenetically modulates leptin in ovarian cells provides a mechanistic link between GLP-1 therapy and improved reproductive outcomes.

How the study worked

Prospective observational study. 207 PCOS patients (135 obese, 72 non-obese) undergoing IVF (March 2020-Jan 2022). Obese patients received liraglutide. LEP promoter methylation in granulosa cells. Serum/follicular fluid leptin. Hormonal profiling.

What this study cannot tell us

Observational. No randomized control for liraglutide. Cannot separate weight loss from direct epigenetic effects. Methylation measured at a population level. IVF outcomes not reported.

How to read the evidence

Prospective observational study with novel epigenetic findings. Good mechanistic insight but needs randomized confirmation.

When this study was published

Published in 2025; data 2020-2022.

The bigger picture

This is among the first studies showing GLP-1 drugs cause epigenetic changes in reproductive cells. If leptin methylation changes improve oocyte quality, this adds a novel mechanism for GLP-1 fertility benefits beyond weight loss.

Questions still open

Does increased LEP methylation improve oocyte quality or IVF outcomes?
Are the epigenetic changes reversible after stopping liraglutide?
Could LEP methylation status predict fertility treatment response?

Common questions

How does liraglutide affect fertility in PCOS?

This study found liraglutide changes the epigenetic regulation of the leptin gene in ovarian cells. By increasing leptin gene methylation (silencing it), liraglutide reduces leptin overproduction, which improves hormonal balance and may enhance egg quality in obese PCOS patients preparing for IVF.

What is epigenetic modification?

Epigenetics refers to changes in gene activity without altering the DNA sequence. Methylation is one such change—adding chemical tags to genes that silence them. This study shows liraglutide adds methylation tags to the leptin gene in ovarian cells, reducing harmful leptin overproduction in PCOS.

Read the original research

Effects of Liraglutide on Leptin Promoter Methylation in Ovarian Granulosa Cells of Obese Polycystic Ovary Syndrome Patients.

The Tohoku journal of experimental medicine, 266(3), 199-207

View on PubMed ↗Publisher’s paper ↗

Citation

Su, Lina; Hao, Xiaoxia; Lu, Wenhong. (2025). Effects of Liraglutide on Leptin Promoter Methylation in Ovarian Granulosa Cells of Obese Polycystic Ovary Syndrome Patients.. The Tohoku journal of experimental medicine, 266(3), 199-207. https://doi.org/10.1620/tjem.2025.J009