Marine macroalgae, particularly Sargassum tenerrimum, have emerged as a significant source of bioactive compounds with potential therapeutic applications. Study focuses on the synthesis, characterization and antidiabetic activity of silver nanoparticles (AgNPs) derived from S. tenerrimum chloroform extract. GC-MS analysis revealed diverse bioactives, including fatty acids such as hexadecanoic acid, oleic acid unsaturated compounds like α-linolenic acid and linoleic acid. These compounds enhance insulin sensitivity, regulate lipid metabolism and support β-cell functionality. Additionally, ethyl isoallocholate and glycine derivatives contribute to insulin synthesis and glucose homeostasis through molecular pathways. AgNPs were synthesized via an eco-friendly approach, confirmed by UV-Vis spectroscopy, FT-IR analysis (hydroxyl and carbonyl functional groups for reduction and stabilization) and SEM imaging (spherical nanoparticles with nanoscale diameters). Glucose utilization assays conducted on L6 skeletal muscle cells demonstrated significant, dose-dependent activity, with 91.26 % glucose uptake. Work highlights the dual role of S. tenerrimum bioactives in glucose metabolism modulation and nanoparticle stabilization, emphasizing their therapeutic synergy. The findings establish S. tenerrimum-derived AgNPs as promising, sustainable agents for managing diabetes, warranting further molecular and pharmacological investigations for broader biomedical applications.