This trial study and compare in blood and urinary matrices the impact of an iron injection on proteins involved in iron metabolism during a blood donation. The goal is to study the impact of an iron injection on detection markers of a blood donation in the anti-doping field

This study aim to investigate the impact of an iron injection on the proteins involved in iron metabolism during blood donation and to compare the blood and urinary matrix. A messenger RNA profiling will be performed as well. The goal is to investigate the impact of iron injection on the markers of blood donation detection in the anti-doping field.

The study will take place over a period of 8 weeks.

Volunteers will be randomly assigned to two groups. Randomization will be provided by a software made for this purpose. An injection of 500 mg of iron in 250mL of saline solution or a placebo injection containing only the saline solution will be performed. Standard blood sampling (in the arm) and finger prick blood sampling will be carried out. After that, 500 mL blood donation will be done. Standard blood sampling and finger prick blood sampling will be performed before and after the donation.

The study will be done in "simple blind", meaning that volunteers will not know if they get iron or saline solution.

On the days of iron or saline solution injection and blood donation, blood sampling will be done up to 12 hours after the injection. After that, blood sampling will be scheduled up to 30 days after blood donation at a rate of once a day (except for the weekends).

Inclusion Criteria:

• Male between 20 and 35 yo
• BMI between 18 and 30
• Ferritin < 50ug/l
• Transferrin saturation < 20 if ferritin between 20 and 50ug/l

Exclusion Criteria:

• high level athlete
• blood donation within 6 months before the study
• liver disorder