Used in research for its ability to inhibit enkephalinase, an enzyme that breaks down enkephalins—natural pain-relieving peptides in the body. By blocking this enzyme, it helps increase and prolong the effects of enkephalins, making it valuable in studying pain modulation and developing analgesic therapies. It has also served as a lead compound in designing drugs for conditions involving neurotransmitter regulation, such as neurological and psychiatric disorders. Its role is primarily experimental, supporting pharmacological studies rather than direct clinical use. Thiorphan is a specialty chemical used as a research tool and intermediate in pharmaceutical development.