Transferrin Saturation

When high

When high (>45%) -- possible iron overload:

• Investigate hereditary haemochromatosis (HFE gene testing) if persistently >50%
• Reduce or stop iron supplementation
• Avoid Vitamin C supplements in excess (enhances iron absorption further)
• Blood donation is therapeutic for iron overload
• Check liver function -- iron overload causes hepatotoxicity (compounding oral AAS liver stress)

Pharmacological / therapeutic options for confirmed iron overload:

• Therapeutic phlebotomy -- 500mL every 1-2 weeks until ferritin <50 ug/L for confirmed haemochromatosis; then maintenance 500mL every 2-4 months; haematologist-supervised
• For non-hereditary iron overload (excess supplementation, transfusion history), donation every 8-12 weeks is usually sufficient
• Iron chelation (deferasirox / Exjade 20-40mg/kg/day, or deferoxamine parenteral) -- reserved for severe overload when phlebotomy is contraindicated or insufficient; physician-supervised; monitor renal/liver function and retinal toxicity
• Note: AAS-driven erythropoiesis increases iron utilisation, so iron overload in active cycle users is uncommon -- persistent elevation warrants HFE testing

When low

When low (<15%) -- confirms iron deficiency:

Supplements:

• Iron Bisglycinate -- 25-50mg elemental iron/day
• Vitamin C -- 500mg with iron dose to enhance absorption
• Low transferrin saturation + low ferritin = true iron deficiency -- supplementation is indicated
• Low transferrin saturation + normal/high ferritin = functional iron deficiency (iron trapped in stores, often from inflammation)

Context for AAS users:

• Regular blood donation to manage high haematocrit depletes iron stores rapidly
• Monitor transferrin saturation alongside ferritin every 8-12 weeks if donating regularly
• Target transferrin saturation 20-35% for optimal erythropoiesis

How to read saturation alongside ferritin and sTfR before donating again: The iron paradox on TRT.