Introduction. Along with and in competition with orthodox medicines, herbal medicines have converted into a popular form of cure. While cumulative investigation reports on adverse effects by herbal drug uptake are few, systematic review along with deep insight into other relevant topics (carcinogenic and noncarcinogenic risk assessment, mechanism of toxicity, and entering toxic metal from source to herbal drug) is sporadic. Methods. Therefore, existing research and their published outputs pointing safety assessment of herbal medicines in terms of toxic metals have been reviewed systematically and information synthesized thematically while suggesting mechanism of toxicity, consequence of prolong exposure, and pathway of toxic metal from source to herbal drugs. Result and Discussion. Our study suggests that most of the herbal medicines were unsafe to consume although claimed harmless. Possible pathways regarding migration of toxic metals into herbal medicine are discussed. Conclusion. There should have appropriate screening from herb collection, and manufacturing to selling of finished herbal medicine by authority concerned is backed.