Nowadays, there were many reports from Viet nam & international laboratories have detected many kinds of undeclared synthesis drugs, even of banned-chemicals in health supplement products (HSP). We developed methods on LC-MS/MS to detect synthesis pharmaceutical drugs in following groups of HSP: strengthen sexual for man group: sildenafil, Tadalafil, Vardenafil; Anti- arthritis group: Dexamethasone, Prednisolon, Betamethasone, Piroxicam; Slimming group: Sibutramin, Orlistate, Phenophtalein, Furosemid. We carried out method validation of specificities & limit of dectections of above drugs on mass spectrometer system of Triple Quad SCiex 55000, analysis 80 samples of each group HSP were collected from 4 provinces: Dong nai, Binh Duong, Ba Ria- Vung Tau, Binh Phuoc in 2020. We validated fragment transition & LOD of each drugs: Sidenafil (mz 475.2 → 100.2/ 283.2), LOD: 0.015ppm;Tadanafil (mz 390.1 → 268.1/262.1) LOD: 0.015 ppm; Vadernafil (mz 483.9 → 312.3/299.2), LOD: 0.07ppm; Prednisolon (mz 361 → 147/343.3), LOD: 0.075ppm; Dexamethason (mz 393.2 → 373.1/293.1); LOD: 0.02 ppm; Betamethason (mz 393.1 → 147.1/355.2)LOD: 0.075 ppm; Piroxicam (mz 330 → 266.2/146.1); LOD: 0.015 ppm; Sibutramin (mz 280.9 → 139/125.2), LOD: 0.75 ppm; Orlistate (mz 496. → 179,2/ 114.1), LOD: 1 ppm; Phenophtalein (mz 319,2 → 141.1/283.2), LOD: 0.01 ppm; Furosemid (mz 329.2 → 285/204), LOD: 0.01 ppm. Screenning results: Sidenafil nondetected/80 samples; Tadalafil positive 10/80 samples, Vadernafil nondetected/80 samples in man sexual enhancement HSP; Prednisonlon nondetected /80 samples, Dexamethason nondetected /80 samples; Betamethason positive 1/80 samples, Piroxicam nondetected /80 samples in anti-arthritis HSP. Sibutramin & Phenolphtalein positive 7/80 samples, Orlistate nondetected/80 samples, Furosemid nondetected/80 samples in slimming HSP.