MS438

MS438 is a highly specific small molecule agonist of the thyroid-stimulating hormone receptor (TSHR). Developed by researchers at the Icahn School of Medicine at Mount Sinai, it has been investigated for its role in regulating energy balance and ingestive behavior. In preclinical studies, intracerebroventricular (ICV) administration of MS438 has been shown to increase blood-hypothalamus barrier (BHB) permeability in fasted mice, resulting in significant increases in food consumption. This effect is associated with a greater loss of body adiposity, increased influx of fatty acids across the BHB, and increased expression of appetite-related markers such as NPY and ghrelin. The compound's mechanism involves signaling through TSHRs located on hypothalamic tanycytes, which appear to crosstalk with insulin-like growth factor 1 receptors (IGF-1R) to modulate metabolic signals and adipose tissue remodeling.