What Are Senolytics? Senescent Cells Explained

Senolytics are compounds that selectively trigger cell death in senescent cells, which have stopped dividing but have not died. They are nicknamed "zombie cells". Senolytics remain a research category, and the term describes an approach rather than a single product.

What is a senescent cell?

Senescence is a stress response in which a cell enters a stable, near-permanent arrest of division yet stays alive and metabolically active. These cells resist apoptosis (programmed cell death) and release a mix of signalling factors called the senescence-associated secretory phenotype (SASP). Triggers studied include telomere dysfunction and persistent DNA damage. Senescent cells vary by type and current markers are not specific, which makes them hard to identify.

How do senolytics work?

One mechanistic classification groups senolytics by the level at which they act: disrupting BH3 protein networks that senescence reorganises, downregulating survival pathways the cells depend on, or modulating homeostatic processes that senescence challenges. Different senescent cell types respond differently, so selectivity is a central question in the field.

What role does the immune system play?

Senescent cells are normally cleared by the immune system, and if they escape it they may accumulate. Immune-directed approaches try to restore that clearance with T cells rather than a small molecule. One example is the peptide SenoMune-0257, which Immorta Bio announced in October 2026 (what is SenoMune-0257). It is still investigational.

Research use only

Peptide Labs supplies research peptides strictly for in-vitro laboratory use only. This article is educational and is not medical advice.

Sources

• •Hallmarks of cellular senescence. Trends in cell biology, 2018.
• •From the divergence of senescent cell fates to mechanisms and selectivity of senolytic drugs. Open biology, 2022.