Estrogen upregulates ornithine decarboxylase (the key spermidine synthesis enzyme) in multiple tissues. Post-menopausal estrogen loss reduces endogenous spermidine production, potentially steeper in women than in age-matched men. This creates a specific rationale for spermidine supplementation in post-menopausal women.

Should post-menopausal women take more spermidine than pre-menopausal women?

The mechanistic rationale supports higher doses post-menopause (3–4 mg/day) vs pre-menopause (1–2 mg/day), given the additional estrogen-loss-related spermidine decline. Human dose comparison data is not available.

Does spermidine affect estrogen levels?

No. Spermidine does not directly affect estrogen synthesis, metabolism, or receptor activity. It addresses downstream cellular mechanisms affected by estrogen loss rather than restoring estrogen itself.