RO4987655 is a selective inhibitor of the enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which plays a key role in regulating cortisol levels within tissues. By inhibiting this enzyme, RO4987655 reduces local cortisol production, particularly in metabolic tissues such as liver and adipose tissue. This mechanism has been explored for the treatment of metabolic disorders including type 2 diabetes and obesity, where elevated cortisol activity contributes to insulin resistance and dyslipidemia.

It has been investigated in clinical trials for improving insulin sensitivity and glucose metabolism. Additionally, due to the role of cortisol in cognitive function and neurodegeneration, RO4987655 has been studied for potential benefits in age-related cognitive decline and conditions like Alzheimer’s disease. Its ability to cross the blood-brain barrier allows for central nervous system activity, making it a candidate for targeting brain-specific cortisol modulation. Research remains primarily in preclinical and early clinical phases, focusing on metabolic and neurological applications.