[Methotrexate use: untangling the real from the fake].

Methotrexate is one of the most important treatments for rheumatologists, however often of great concern to the non-specialist. This article reviews some useful aspects to know, in terms of safety with no major infectious risk or risk of pulmonary fibrosis, but also the benefits of using the subcutaneous route, the addition of low dose folic acid, the association with hydroxychloroquine or a short stop with flu vaccination, practical elements to demystify a safe and useful treatment.