Abstract

Phytochemicals such as polyphenols, terpenoids and alkaloids show robust anti-obesity activity in vitro and in 
animal models through modulation of adipogenesis, lipolysis, thermogenesis, inflammation, insulin signaling 
and gut microbiota. However, their translation into effective human therapies is hampered by poor aqueous 
solubility, low oral bioavailability, rapid metabolism and limited tissue targeting. Nanotechnology-based 
delivery systems offer a rational solution by protecting phytochemicals from degradation, enhancing absorption, 
prolonging circulation and directing them to metabolically relevant tissues. This review summarizes the 
molecular mechanisms by which key phytochemicals exert anti-obesity effects, outlines pharmacokinetic barriers 
and describes major classes of nanocarriers, including lipid-based nanoparticles, nanoemulsions, polymeric 
systems, phytosomes and hybrid platforms. We discuss targeted and stimuli-responsive nanoformulations aimed 
at adipose tissue, liver and gut, and highlight preclinical evidence that nanoencapsulation enhances efficacy of 
curcumin, resveratrol, catechins, berberine and related compounds. Finally, we examine safety, quality, 
regulatory and equity challenges, and propose future directions for integrating nanoformulated phytochemicals 
into precision obesity therapy.