From the original article in 2021. Author: Ray Peat.
Classifying progesterone as a “pregnancy hormone” and a “female sex hormone” has seriously limited understanding of its function in both men and women. It is a stabilizer of cellular structure and function in all organs, similarly in men and women. This stabilizing effect is especially important in the nervous system, where it is protective against stress. In both men and women, a progesterone deficiency is associated with problems including seizures and bipolar disorder, irritability/elation, aggression, and depression, as well as sex-related problems.
In the 1970s, an acquaintance told me that he had become impotent following his vasectomy. I was familiar with the progesterone deficiency produced in women by tubal ligation and by intrauterine contraceptive devices, and I had seen a study of men’s hormones following a vasectomy, in which an isolated deficiency of progesterone sometimes occurred, so he decided to try some progesterone. He later said that a single dose had corrected his erectile problem. Other young men with erectile dysfunction, from other causes, had similarly good results with small amounts of progesterone.
When a problem is quickly and permanently corrected with a small amount of progesterone it seems likely that the progesterone acted in the brain to shift the balance, maintained by endorphins, away from the stress induced inhibition of progesterone and testosterone synthesis. At the same time, though, that progesterone is lowering cortisol, it is also reducing inflammation, partly by acting as an antagonist to aldosterone. Increased aldosterone is associated with erectile dysfunction (Chang, et al., 2019; Wu, et al., 2018, 2016), and it interacts locally as a testosterone antagonist. In this, and other situations involving testosterone antagonists (estrogen, cortisol, aldosterone), progesterone can have a directly testosterone- supporting effect.
After the age of 35 or 40, many men experience a decline in their resistance to stress, corresponding to the decline in protective substances such as DHEA and progesterone. Often a small amount of progesterone, 5 or 6 mg (for example, a drop of Progest-E the size of an unpopped kernel of popcorn) can make a difference, sometimes lasting for a few days or more. Paying close attention, the effects are usually noticeable within about half an hour. At a certain level, progesterone can antagonize the effects of testosterone; in younger men, 2 or 3 drops can have that effect. That effect passes within a day of stopping the progesterone. If a younger man uses progesterone topically, for example for sunburn, a little olive oil should be applied to the skin first to make it spread easily; if it’s used on a large area, the same anti- testosterone effect is likely to be noticed.
Surgery. 2019 Mar;165(3):622-628. Risk of severe erectile dysfunction in primary hyperaldosteronism: A population-based propensity score matching cohort study. Chia-Hui Chang, Shih-Chieh J Chueh, Vin-Cent Wu, Likwang Chen, Yen-Hung Lin, Ya-Hui Hu, Kwan-Dun Wu, Yao- Chou Tsai.
Asian J Androl. Jan-Feb 2018;20(1):24-29. Aldosterone induces inflammatory cytokines in penile corpus cavernosum by activating the NF-κB pathway. Fei Wu, Zu-Quan Xiong, Shan-Hua Mao, Ji- Meng Hu , Jian-Qing Wang, Hao-Wen Jiang, Qiang Ding.
World J Urol. 2016 Jul;34(7):999-1007. Elevated plasma aldosterone is an independent risk factor for erectile dysfunction in men. Fei Wu, Shanhua Mao, Tianfang Yu, Haowen Jiang, Qiang Ding, Gang Xu.
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