Rapamycin, an mTOR inhibitor affects senescence through suppression of senescence-associated secretory phenotype (SASP). We studied the safety and feasibility of low-dose rapamycin and its effect on SASP and frailty in elderly undergoing cardiac rehabilitation (CR). 13 patients; 6 (0.5mg), 6 (1.0mg), and 1 patient received 2mg oral rapamycin (serum rapamycin <6ng/ml) daily for 12 weeks. Median age was 73.9±7.5 years and 12 were men. Serum interleukin-6 decreased (2.6 vs 4.4 pg/ml) and MMP-3 (26 vs 23.5 ng/ml) increased. Adipose tissue expression of mRNAs (arbitrary units) for MCP-1 (3585 vs 2020, p=0.06), PPAR-γ (1257 vs 1166), PAI-1 (823 vs 338, p=0.08) increased, whereas interleukin-8 (163 vs 312), TNF-α (75 vs 94) and p16 (129 vs 169) decreased. Cellular senescence-associated beta galactosidase activity (2.2% vs 3.6%, p=0.18) tended to decrease. We observed some correlation between some senescence markers and physical performance but no improvement in frailty with rapamycin was noted. (NCT01649960).