A new pilot study published in NPJ Aging suggests that semaglutide — the active ingredient in Ozempic and Wegovy — may do more than control blood sugar and reduce body weight. In people with HIV and a form of fatty liver disease, the drug appeared to slow biological aging at the cellular level, adding a potentially significant new dimension to GLP-1 research.
What the Study Found
The research was a post hoc analysis of the SLIM LIVER trial (formally known as ACTG A5371, registered January 2, 2020 under NCT04216589). The single-arm trial enrolled 41 people with HIV (PWH) who also had metabolic dysfunction-associated steatotic liver disease, or MASLD — a condition involving excess fat buildup in the liver tied to metabolic problems.
Participants received semaglutide at 1.0 mg weekly for 24 weeks. Beyond the already-known benefits of reduced liver fat and improved metabolic health, researchers specifically examined epigenetic aging — a biological measure of how fast cells are aging at the DNA level, which can differ significantly from a person's actual calendar age.
The pilot analysis aimed to evaluate whether semaglutide treatment affected these epigenetic aging markers and whether any changes in aging were linked to how well patients responded to treatment overall.
Why This Matters for GLP-1 Users
Epigenetic clocks are increasingly used by researchers as a window into overall health trajectory. When biological age outpaces chronological age, it is associated with higher risks of disease and early death. People with HIV already face accelerated epigenetic aging due to the virus itself and long-term antiretroviral therapy, making this population particularly relevant for studying aging interventions.
Semaglutide is already known to reduce inflammation and liver fat — two drivers of accelerated biological aging. This study suggests those effects may translate into measurable changes at the epigenetic level, though it is important to note this was a small pilot study and the findings are preliminary.
Key takeaway: This small, 24-week pilot study suggests semaglutide may slow epigenetic aging in people with HIV and fatty liver disease — but with only 41 participants and no control group, larger randomized trials are needed before drawing firm conclusions.
Important Limitations to Keep in Mind
This was a post hoc analysis, meaning aging was not the original primary goal of the SLIM LIVER trial — it was examined after the fact. The trial was also a single-arm study, meaning there was no placebo group for direct comparison. With just 41 participants, the findings are hypothesis-generating rather than definitive. Independent replication in larger, controlled trials will be necessary to confirm whether semaglutide genuinely slows biological aging.
What to Watch Next
This research adds to a growing body of evidence exploring GLP-1 receptor agonists as potential tools against aging-related disease. Future studies will need to test semaglutide's effects on epigenetic aging in broader populations — not just people with HIV — and compare results against a placebo arm. Researchers will also want to determine which specific epigenetic changes are most meaningful for long-term health outcomes.
Frequently Asked Questions
If you are taking semaglutide or considering it for any reason, speak with your prescriber about what the latest research means for your individual health situation. Study findings in specialized populations may not apply directly to your circumstances.
- Peer-reviewed journal article, NPJ Aging, 'Pilot study of epigenetic aging and treatment response to semaglutide in the SLIM LIVER study,' date not specified in source material.