STOP: Iron Supplementation for Endometriosis

Conventional Rationale#

Endometriosis patients frequently present with anemia or low serum iron. Standard clinical practice is to prescribe iron supplementation to correct the apparent deficiency. This seems logical on the surface—the patient is iron-deficient, so give them iron.

Why It's Counterproductive#

The microbiome signature reveals that this reasoning is backwards. The key evidence:

Hepcidin is elevated in endometriosis. Hepcidin increases in the presence of high iron and decreases during true iron deficiency. Its elevation is an indicator of functional anemia—the body is deliberately sequestering iron as a host defense mechanism (Primitive 2: Nutritional Immunity as Interpretive Constraint).^{[1]Pendergrass 2026 — Endometriosis Conference Presentation (Amsterdam)Karen Pendergrass · 2026Open reference 1 ↓}

Lactoferrin and calprotectin are already elevated—the body is actively chelating iron and zinc away from pathogens. These are the host's own siderophore-binding defenses.

Key pathogenic taxa express advanced iron uptake systems. E. coli produces siderophores for iron acquisition, essential for growth and biofilm formation. B. fragilis pirates iron from other microbes.

Streptococcus agalactiae also engages in iron piracy.

Iron supplementation feeds these pathogens directly, amplifying the iron-rich, pro-inflammatory microenvironment that drives lesion survival, invasion, and perpetuation of the condition.

Clinical observation confirms this: iron and zinc supplementation is consistently found to exacerbate symptoms in endometriosis patients.^{[1]Pendergrass 2026 — Endometriosis Conference Presentation (Amsterdam)Karen Pendergrass · 2026Open reference 1 ↓}

Knowledge Primitive#

Primitive 2: Nutritional Immunity as Interpretive Constraint—Low serum iron is a host defense, not a deficiency to be corrected.