Flaxseed polysaccharide gum (FPG) was extracted through the ultrasound-assisted process using water as a solvent with a yield ranging from 8.05 ± 0.32% to 12.23 ± 0.45% by changing different extraction variables. The extracted FPG was analyzed for its functional groups and antioxidant potential. The maximum DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity (≈100%) of FPG was noted at concentrations beyond ≈10 mg·ml. The maximum inhibition percentage through ABTS (2,2'-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid) (72.4% ± 1.9%) was noted at 40 mg·ml, which was observed to be less when compared to DPPH at the same concentration. The total antioxidant potential of the FPG solution at a concentration of 10 mg·ml was equivalent to 461 mg ascorbic acid, which tends to increase with concentration at a much lower scope. The in vivo trial suggested that the least weight gain was noted in experimental groups G and Gh. A significant reduction in total cholesterol was noticed in G (-14.14%) and G (-17.72%) and in Gh (-22.02%) and Gh (-34.68%) after 60 days of the trial compared to the baseline values. The maximum reduction in total triglyceride was observed in Gh (-25.06%) and Gh (-22.01%) after 60 days of the trial. It was an increasing trend in high-density lipoprotein cholesterol (HDL-c) in different experimental groups G (10.51%) than G (5.35%) and Gh (48.96%) and Gh (31.11%), respectively, after 60 days of study interval. Reduction of -5.05% and - 9.45% was observed in G and G, while similar results were observed in Gh and Gh. Conclusively, results suggested a possible protective role of FPG against hyperlipidemia.