ABTRACTThe present study aimed to define preliminary quality control standards for Thor-ra-nee-san-tha-kat (TSK), a Thai traditional medicine indicated for the treatment of muscle pain caused by abdominal rigidity and for severe constipation. TSK is comprised of black pepper seeds (Piper nigrum, 60% w/w), Aloe vera sap (12.5% w/w) and 24 other ingredients. Organoleptic, microscopic, phytochemical and physicochemical properties, and levels of heavy metal and microbial contamination were determined according to the methods of the Thai Herbal Pharmacopoeia. TSK is a brown, bitter tasting powder with a pungent odor. Microscopic examination revealed mesocarp filled with yellow oil glands, beaker cells of endocarp and stone cells from P. nigrum. Phytochemical analysis revealed the presence of alkaloids, anthraquinones and polyphenolics. Heavy metal analysis indicated the presence of arsenic, cadmium and lead within the allowable range limits.