Peat Archive

Ray Peat's work on fertility ties together his central themes: the importance of progesterone, the dangers of estrogen dominance, and the role of thyroid function in reproductive health. He noted that both male and female fertility have declined dramatically in modern populations, correlating with increased PUFA consumption, estrogen exposure (xenoestrogens, phytoestrogens), and declining thyroid function.

For women, Peat emphasized that progesterone is essential for maintaining pregnancy, that estrogen dominance causes miscarriage and menstrual problems, and that thyroid function must be adequate for ovulation and implantation. For men, he noted that PUFAs, estrogen, and endotoxin suppress testosterone production and sperm quality. He advocated for progesterone supplementation, thyroid support, and PUFA avoidance for both sexes.