The P/E2 ratio captures the balance between the two primary female sex hormones across the cycle.
The P/E2 ratio captures the balance between the two primary female sex hormones across the cycle. A low ratio — "oestrogen dominance" — is associated with PMS, heavy periods, fibrocystic breasts, endometriosis, fibroids, mood dysregulation, and potentially increased breast and endometrial cancer risk. Common in perimenopause but often missed.
Low (oestrogen-dominant): anovulatory cycles, perimenopause, PCOS, obesity (adipose aromatisation), xenoestrogen exposure (plastics, personal-care products), high alcohol intake, hypothyroidism. High: exogenous progesterone supplementation, progestogen contraception, early pregnancy.
Low: bloating, breast tenderness, heavy periods, premenstrual mood swings, migraines, sleep disruption, reduced libido, anxiety, brain fog, difficulty losing weight.
Cruciferous vegetables (DIM, I3C) promote oestrogen clearance. Flaxseed lignans. Zinc, vitamin B6 support corpus luteum and progesterone synthesis. Adequate dietary fat for steroid precursors.
Alcohol reduces hepatic oestrogen metabolism. Conventional dairy and non-organic meat contain exogenous oestrogens. Plasticisers (BPA, phthalates) act as xenoestrogens.
Educational information only — not a diagnosis. Every Pheno result is interpreted in context and reviewed by a physician.
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