Enables the transfer of a solute or solutes from one side of a membrane to the other according to the reaction: ATP + H2O + sterol(in) = ADP + phosphate + sterol(out).
Reactome:R-HSA-265783 "ABCG5:ABCG8 transports sterols from cytosol to extracellular region"; Reactome:R-HSA-5679101 "Defective ABCG8 (in ABCG5:ABCG8) does not transport sterols from cytosol to extracellular region"; Reactome:R-HSA-5679145 "Defective ABCG5 (in ABCG5:ABCG8) does not transport sterols from cytosol to extracellular region"