Principal component analysis of synthetic adulterants in herbal supplements advertised as weight loss drugs. 
Obesity is one of the major problems in many countries.  Herbal drugs are widely used to treat obesity.  Unfortunately the majority of herbal weight loss drugs are adulterated with active pharmaceutical ingredients.  The purpose of the present study was to analyse herbal weight loss drugs for the general search for pharmaceuticals.  sixty one herbal weight loss drugs that were collected from herb shops and internet in Kermanshah, Iran were analysed qualitatively using gas chromatography/mass spectrometry.  Of the 61 weight loss products sampled, 72% were found to be adulterated with tramadol, caffeine, fluoxetine, rizatriptan, venlafaxine and methadone.  Herbal weight loss products were adulterated with controlled and legitimate drugs.  Patients should be aware of the danger of using adulterated supplements.