The suitability of new drugs for use in the general population in terms of risk and benefit is assessed by the health authorities through their drug agencies. These agencies regulate the entry of drugs on the market and their conditions for use according to strict criteria of quality, safety and efficacy. To preserve the principle of transparency, the requirements are previously published as guidelines, which are freely available on the Internet. All these guidelines have the following basic recommendations in common: (a) appropriate methodology for the objective, defined in detail a priori, (b) traceability, (c) verification of the appropriateness of the methodology applied, (d) justification of any deviation from the initial plan and (e) demonstration of the robustness of the results in distinct scenarios. Regulatory guidelines differ from other methodological references in their emphasis on the practical issues of the design and performance of studies, accepted methodological principles, and systems to ensure quality assurance in research. Although these requirements might not be universally applied to all types of research, the guidelines are freely available and are a good reference for the authorship, review and publication of clinical trials. The present article aims to review some of the guidelines that could be especially useful.