Tacrolimus 8-epimer is primarily used in biochemical and pharmacological research to study structure-activity relationships, especially in immunosuppression mechanisms. Structurally similar to tacrolimus, an immunosuppressant employed in organ transplantation to prevent rejection, it acts as a comparative analog to elucidate interactions with target proteins like calcineurin and immunophilin binding. This facilitates the development of novel therapeutics with improved efficacy or reduced side effects. Its epimeric configuration at the 8-position may modify binding affinity, pharmacokinetics, and toxicity profiles, making it valuable for drug metabolism studies and formulation optimization. It is also investigated in research contexts for potential applications in autoimmune diseases and topical treatments for dermatological conditions such as atopic dermatitis.