Why oestrogen metabolites matter
Standard blood oestrogen tests measure total circulating oestradiol at a single timepoint. They reveal nothing about what the body does with that oestradiol — which metabolic pathways process it and whether the resulting metabolites are protective or harmful.
2-OH-oestrone (2-OH-E1) — the protective pathway, methylated by COMT to the inert 2-methoxy form.
4-OH-oestrone (4-OH-E1) — genotoxic. Forms DNA adducts. Elevated with CYP1B1 activation and COMT insufficiency.
16-OH-oestrone (16-OH-E1) — proliferative. Strongly oestrogenic. Elevated with insulin resistance and environmental toxin exposure.
The 2:16-OH-E1 ratio is a validated risk modifier for oestrogen-dependent conditions. Understanding which pathway dominates informs both risk stratification and therapeutic intervention.