Proton-dependent transporter of monocarboxylates such as L- lactate and pyruvate (PubMed:11101640, PubMed:23935841, PubMed:31719150). Plays a predominant role in L-lactate efflux from highly glycolytic cells (By similarity). {ECO:0000250|UniProtKB:O35910, ECO:0000269|PubMed:11101640, ECO:0000269|PubMed:23935841, ECO:0000269|PubMed:31719150}. This is the function of Ensembl gene identifier ENSG00000141526 (SLC16A3, solute carrier family 16 member 3).