Background: Tamra bhasma (TB) is copper based herbo-metallic preparation which is used extensively by Ayurvedic practitioners. Tamra bhasma is endorsed for different disorders of liver, abdominal pain, heart disease, colitis, tumors, anemia, loss of appetite, tuberculosis, as well as eye problems. Objective: Our aim is to characterize 5 commercial TB preparations from 5 different manufacturers by using modern scientific techniques and to study there bioavailability in Wistar rats. Materials and Methods: Tamra bhasma was characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy Dispersive X-ray analysis (EDAX), Nanoparticle tracking analyzer (NTA), Inductively coupled plasma optical emission spectroscopy (ICP-OES). Bioavailability of Tamra bhasma was studies using non compartmental rat model with daily dose of 6.45mg/kg according to their body weight. Results: The colour of one of the TB preparation was different from other 4 TB samples. The chemical phase and particle size is significantly different for all the 5 TB’s. Pharmacokinetic model confirms difference in various PK parameters such as peak concentration (Cmax), half-life (t1/2) and terminal elimination slope (λz) for all 5 TB’s. TB-A showed highest Cmax (82.21 mg/L), whereas TB-E showed lowest Cmax (48.69 mg/L). The highest bioavailability of TB is may be due to specific chemical moiety and morphology. Based on XRD and elemental analysis, it was found that manufacturing route followed for one of the preparation is not as per ayurvedic text reference. Conclusions: The morphology as well as chemical phase of the five TB’s studied were different from each other, which might be responsible for different pharmacokinetic profiles in Wistar rat model.