This study investigates the effect of intravenous iron substitution in non-anaemic premenopausal women with iron deficiency on:

• Changes in the cerebral Dopamine (DA) receptor density after iron substitution, shown by brain PET
• Reduction of fatigue and other neuropsychological symptoms after iron supplementation

Inclusion Criteria:

• Healthy female subjects, Age > 18 years, premenopausal, regularly menstruating
• BMI 18-25 kg/m2
• Serum ferritin level < 15 μg/ml, Hb > 120 g/L
• Adequate contraception during the study period
• Fatigue determined as 2 or more points in the basic questionnaire for fatigue
• Informed consent

Exclusion Criteria:

• Day-night shift work
• 11 or more points in the BDI
• No psychiatric disease (as assessed by neuropsychiatric assessment)
• 15 or more points in the ISI
• Known hypersensitivity to iron carboxymaltose, iron sucrose or iron sulfate
• Intake of iron preparations during the last 8 weeks before the start of the trial protocol
• Pregnancy or lactation
• Any cardiovascular or pulmonary disease
• Acute or chronic infection/inflammation or malignancy
• Other obvious physical or psychiatric causes for fatigue (known mental disorders, e.g. depression)
• Chronic intake of concurrent medication (especially antipsychotic drugs), except oral contraceptives. Sporadic intake of NSAID or paracetamol, e.g. in the case of a common cold or sporadic headaches is allowed.
• CRP > 10 mg/L
• TSH out of normal range
• Any concurrent medical condition(s) that, in the view of the investigator, would prevent compliance or participation or jeopardize the health of the patients.
• Participation in any other therapeutic trial within the previous month
• Known History of HIV/HBV/HCV

The patients will be blinded with respect to the treatment sequence. The outcome assessor (PET scan evaluator) will be blinded with respect to the participant identity and the date of the PET scan.