What Are Senescent Cells?
Cellular senescence is a stress response. Senescent cells stop dividing but remain alive, secreting a cocktail of inflammatory molecules called the SASP (Senescence-Associated Secretory Phenotype). This causes chronic inflammation, damages neighboring cells, promotes cancer, and impairs stem cells.
By age 60-70, senescent cells may represent only 2-5% of total cells — but their outsized inflammatory impact drives many age-related diseases.
The Senolytic Revolution
In 2015, James Kirkland's lab at Mayo Clinic showed that clearing senescent cells from aging mice extended lifespan by 25%. The drugs used — dasatinib combined with quercetin — became the first senolytic cocktail.
Other compounds identified include fisetin (from strawberries), navitoclax, and Unity Biotechnology's UBX1325.
The typical protocol involves taking D+Q for 2-3 consecutive days, then resting for weeks to months before repeating — senescent cells accumulate slowly.
