Blinded Randomized Placebo-Controlled Study Efficacy and Safety of Injectafer in ID Patients With Fibromyalgia

Inclusion Criteria: * Male or female subject's ≥ 18 years of age, able to give informed consent to the study. * Fibromyalgia diagnosis based on The 2011 modification of the American College of Rheumatology (ACR) 's 2010 preliminary criteria for diagnosing fibromyalgia (2011ModCr) * A baseline score ≥ 60 on the FIQR * Subject's current medications to treat fibromyalgia, including pain medicines, anti-depressants, sleep medications must be on a stable dose for at least 30 days. * Subject's current narcotic medication must be on a stable dose for at least 30 days prior to randomization * Subjects at risk for pregnancy must have a negative pregnancy test at baseline and be practicing an acceptable form of birth control: have had a hysterectomy or tubal ligation, or otherwise be incapable of pregnancy, or have practiced any of the following methods of contraception for at least one month prior to study entry: hormonal contraceptives, spermicide and barrier, intrauterine device, partner sterility. Exclusion Criteria: * Parenteral iron use within 4 weeks prior to screening. * History of \> 10 blood transfusions in the past 2 years. * Anticipated need for blood transfusion during the study. * Known hypersensitivity reaction to any component of Injectafer® (Ferric Carboxymaltose). * Current or acute or chronic infection other than viral upper respiratory tract infection * Malignancy (other than basal or squamous cell skin cancer or the subject has been cancer free for ≥ 5 years). * Active inflammatory arthritis (e.g. rheumatoid arthritis, SLE). * Pregnant or lactating women. * Severe peripheral vascular disease with significant skin changes. * Seizure disorder currently being treated with medication. * Baseline ferritin ≥ 50 ng/mL. * Baseline TSAT ≥ 20%. * History of hemochromatosis or hemosiderosis or other iron storage disorders. * Known positive hepatitis with evidence of active disease. * Hemoglobin greater than the upper limit of normal. * Calcium or phosphorous outside the normal range. * Known positive hepatitis B antigen (HBsAg) or hepatitis C viral antibody (HCV) with evidence of active hepatitis (i.e., AST/ALT greater than the upper limit of normal). * Known positive HIV-1/HIV-2 antibodies (anti-HIV) * Received an investigational drug within 30 days before randomization. * Chronic alcohol or drug abuse within the past 6 months. * Any other pre-existing laboratory abnormality, medical condition or disease which in view of the investigator participation in this study may put the subject at risk. * Subject unable to comply with the study requirements.