Targeted delivery of potent cytotoxic drugs to cancer cells minimizes systemic toxicity and several side effects. NHC*−Au−Cl has already been proven to be a potent anticancer agent. In this study, we explore a strategy based on chemoselective cysteine conjugation of NHC*−Au−Cl to albumin and trastuzumab (Thiomab LC‐V205C) to potentiate drug‐ligand ratio, pharmacokinetics, as well as drug efficacy and safety. This strategy is a step forward towards the use of gold‐based anticancer agents as targeted therapies. Golden therapy: Synthesis of NHC*−Au−S‐protein bioconjugates to increase stability, modulate pharmacokinetics, and ultimately enhance efficacy and safety of gold‐based anticancer drugs. The findings reported represent a step forward towards the use of gold‐based anticancer drugs as targeted therapies.