Clinical Research Directory

Inclusion Criteria: * Age ≥ 18 years; * Weight ≥ 50 kg; * Drug-resistant RLS; * Severe to very severe RLS (IRLSSG-Q score \> 20), persistent or recurrent for more than one month; * Treatment with dopamine agonists without exceeding the recommended doses (ropinirole ≤ 2 mg/day, pramipexole ≤ 0.54 mg/day, rotigotine ≤ 3 mg/day); * Treatment with dopamine agonists and/or α2δ ligands and/or opioids that has been stable for at least 3 months; * In cases of sleep apnea syndrome, treatment with continuous positive airway pressure (CPAP); * Participants were required to be fluent in spoken and written French, be enrolled in a health insurance plan, agree to the automated processing of anonymized confidential data, and have provided written, informed consent for the study. Exclusion Criteria: * Iron supplementation (oral or intravenous) within 3 months prior to enrollment and throughout the study period * Serum ferritin \< 50 µg/L or \> 300 µg/L; * Transferrin saturation \< 20% or \> 45%; * Hemochromatosis; * RLS augmentation syndrome ; * Treatment with neuroleptics or antidepressants; * Allergy to iron; * Severe infectious or inflammatory disease within the past 3 months; * RLS associated with chronic kidney disease, pregnancy, or a clinically significant neurological or psychiatric disorder; * Severe sleep apnea syndrome (AHI \> 30/h) that is untreated, or in cases where treatment is refused or has failed; * Known allergy, inflammatory, or immune disorder; * History of severe asthma, eczema, or any other atopic allergy; * Pregnancy or breastfeeding; * Also excluded are patients participating in another research study, those deprived of their liberty by judicial or administrative order, those living in a medical facility, those subject to a legal protection order, or those from whom consent could not be obtained.