Abstract
This article is divided into four parts. The first part describes how homeopathic products are prepared and shows that, according to Avogadro’s Principle, the vast majority of them do not contain the product that is intended to be administered to the patient, or, in other words, they contain only the excipient. A few only contain such small quantities that, as pharmacology establishes, it can be assumed that they lack the capacity to cure any disease. According to the above, all scientific studies prove that their healing capacity is not superior to that of a placebo. The second part is dedicated to those who wish to know the history of homeopathy, the third reviews the opinions of some scientific institutions about it and the fourth includes some general considerations.