MOMAST® is a patented natural phenolic complex, rich in tyrosol (9.0 g/kg, Tyr), hydroxityrosol (43,5 g/kg, OH-Tyr), and verbascoside (5.0 g/Kg), which is obtained from the OVW by-product of the Coratina cultivar with potent direct antioxidant activity (measured by DPPH and FRAP assays, respectively). Indeed, MOMAST® represents an innovative sustainable bioactive ingredient which has been obtained with ethical and empowering behavior by applying the principles of a circular economy. In the framework of research aimed at fostering its health-promoting activity, in this study it was clearly demonstrated that MOMAST® treatment reduced the oxidative stress and levels of total cholesterol (TC) and low-density lipoprotein (LDL) cholesterol, and increased the HDL levels, without changes in the triglyceride (TG) levels in Western diet (WD)-fed mice. The modulation of the plasmatic lipid profile is similar to red yeast rice (RYR) containing Monacolin K (3%). In addition, at the molecular level in liver homogenates, similarly to RYR, MOMAST® exerts cholesterol-lowering activity through the activation of LDL receptor, whereas, unlike RYR, MOMAST® reduces proprotein convertase subtilisin/kexin type 9 (PCSK9) protein levels via hepatic nuclear factor 1 (HNF1)-α activation. Hence, this study provides the proof of concept regarding the hypocholesterolemic activity of MOMAST, which could be successfully exploited as an active ingredient for the development of innovative and sustainable dietary supplements and functional foods.