The evidence-based medicine apply drug treatments, diagnostic or therapeutic procedures that have demonstrated effectiveness and efficiency in a scientific manner in a given population. The science-based medicine adds, in addition to the above definition, the idea of plausibility, according to scientific knowledge in medicine, pharmacology or any other branch of science (biology, chemistry, physics, etc.). This type of medicine is considered by most health professionals as one of the pillars which should sustain current medicine because it avoids the subjectivity inherent in human being, and discard ineffective or even harmful procedures for patients. The therapeutic protocols for the most common pathologies are also described. Finally, the most used alternative medicine in the West will be described as well as their degree of plausibility and evidence.