Testosterone Treatment for Relapsing Remitting MS

Inclusion Criteria: * Man between 18 and 55 years * Patient affiliated to a social health insurance plan * Patient able to understand the objectives and risks related to the research and able to comply with the requirements of the protocol throughout the duration of the study * Patient having been informed of the results of the prior medical examination * Patient having signed an informed consent * Confirmed and documented diagnosis of MS, as defined by the revised McDonald criteria, * Patient who have been receiving one of the following disease modifying therapies for at least one year prior to randomization: natalizumab , fingolimod, ponesimod, ocrelizumab, or ofatumumab, in accordance with their prescribing information. Switching from one molecule to another during the previous year is also permitted, provided that the switch was motivated by a non-neurological reason (relapse, MRI activity). Patients receiving ocrelizumab within 6 to 9 months are eligible, provided they have received full-dose ocrelizumab for at least 2 years. * Biological hypogonadism defined by serum total testosterone levels below 20 nmol / L (checked by blood sampling during the screening visit) * For patients under natalizumab : Negative status for JC virus or JC virus synthesis index ≤ 1.5 (checked by blood sampling at the inclusion visit) * No relapses in the year prior to inclusion * Disability status during the selection visit with an EDSS score of 0 to 7 (verified by questionnaire during the inclusion visit) * Stable neurological state in the month preceding randomization Exclusion Criteria: * Patients with progressive MS (primary or secondary) * Patients with hypogonadism with clinical symptoms and treated with androgens * Patients with PSA (prostate specific antigen)\> 2.5 ng / ml (for an age less than 49 years old) or \> 3.5 ng / ml (for age ≥ 50 years) (checked by a blood test at the inclusion visit) * Patients with a hematocrit level \> 54% (checked by blood sampling during the inclusion visit) * Patients refusing or unable to undergo an MRI * Patients with any other disease other than MS that may contribute to neurological symptoms and signs or affect their evaluation * Patients with neurological signs compatible with progressive multifocal leukoencephalopathy (PML) or confirmed leukoencephalopathy * Patients diagnosed with untreated sleep apnea * Patients with or having had cancer or tumors of the liver, heart, kidney, prostate or mammary gland * Patients with cardiovascular, renal, hepatic, hematological, gastrointestinal, pulmonary, uncontrolled diseases * Patients wishing to procreate during the study period * Patients with chronic infectious disease * Patients with organic or psychiatric disease compromise their ability to understand the information given and to follow the protocol * Patients with a history of hypersensitivity to treatment or any of the excipients, or drugs of similar chemical classes * Patients who used experimental drugs and / or who participated in clinical drug trials in the 6 months prior to selection * Patient in exclusion period (determined by previous study or in progress) * Impossibility of giving information to the patient (subject in emergency situation, difficulties in understanding the subject or other) * Incapacitated subject (subject to a legal protection measure: safeguard of justice, curatorship, guardianship, future protection mandate, family habilitation)