Despite over 230 years of existence, the mechanism of action of homeopathic drugs remains unclear. The two fundamental principles of homeopathy - ‘Similia similibus curantur’ (like cures like) and the concept of water memory - have faced periodic scrutiny from scientists and skeptics. The mechanism of homoeopathic drug action has been categorized under - Enzyme co-factor concept, Molecular mechanism concept, Nano-particle concept together with the concept of Memory of water. While each concept has some scientific basis, the enzyme co-factor concept, nano-particle concept, and memory of water concept are grounded in more substantial scientific evidence, providing a plausible explanation for the mechanism of homeopathic drug action.