A convenient, sterile-filtered cocktail solution (1000X, in DMSO) containing four small molecules useful for enhancing the reprogramming efficiency of human somatic cells to induced pluripotent stem cells (iPSCs). The four products in the cocktail are: A83-1 (Cat. No. 1725, a ALK5 kinase inhibitor, 0.5 mM), CHIR99021 (Cat. No. 1677, a selective GSK-3β inhibitor, 3.0 mM), PD0325901 (Cat. No. 1643, a MEK inhibitor, 0.5 mM), and Thiazovivin (Cat. No. 1681, an enhancer of hESCs survival, 0.5 mM).