Common Antioxidant NAC Shows Senolytic Activity in Human Endothelial Cells

N-acetylcysteine (NAC), best known as a mucolytic and antioxidant available over-the-counter, may have a second career as a senotherapeutic. This study found that NAC counters cellular senescence in human endothelial cells—the cells lining blood vessels—by modulating the HuR pathway, a key regulator of inflammatory gene expression. The researchers demonstrated that NAC not only prevents senescence but may help clear already-senescent cells. This matters because vascular endothelial senescence is a major driver of age-related cardiovascular disease. Unlike experimental senolytics that are years from clinical use, NAC is already widely available, well-tolerated, and inexpensive. However, important caveats apply: this was an in vitro study in cultured cells, not a human trial. The effective doses and whether oral NAC reaches sufficient tissue concentrations in living people remain unknown. Still, the finding is intriguing enough to warrant clinical investigation, especially given NAC's established safety profile. It also reinforces that senotherapeutic effects might hide in plain sight among existing medications and supplements—we just need to look systematically.