From the Guidelines
Progesterone can decrease testosterone levels by suppressing androgen secretion and increasing the production of sex hormone-binding globulin (SHBG) [ 1 ].
Mechanism of Action
- Progesterone can bind to androgen receptors, blocking the effects of testosterone
- Increase the production of SHBG, which can bind to testosterone and reduce its availability [ 1 ]
Clinical Implications
When taken in high doses, such as in certain contraceptive medications like medroxyprogesterone acetate (Depo-Provera) or in hormone replacement therapies like progesterone, it may lead to a reduction in testosterone production [ 1 ].
Precautions
Individuals taking progesterone should be monitored for potential changes in testosterone levels, particularly if they are experiencing symptoms such as low libido, fatigue, or erectile dysfunction [ 1 ].
Key Points
- Progesterone can decrease testosterone levels
- SHBG production is increased, reducing testosterone availability
- Monitoring is necessary for individuals taking progesterone, especially if experiencing symptoms related to low testosterone [ 1 ]
From the FDA Drug Label
a) Plasma and urinary steroid levels are decreased (e. g. progesterone, estradiol, pregnanediol, testosterone, cortisol).
The progesterone medication decreases testosterone levels, as indicated by the decrease in plasma and urinary steroid levels, including testosterone 2.
From the Research
Effect of Progesterone on Testosterone Levels
- The relationship between progesterone and testosterone levels is complex and can be influenced by various factors, including the type and dose of progestin used 3, 4.
- Some studies suggest that progestins, such as desogestrel, levonorgestrel, and norethisterone, can increase free testosterone levels by displacing testosterone from sex hormone-binding globulin (SHBG) 3.
- However, other studies have found that combinations of ethinyl estradiol and certain progestins, such as desogestrel or norethisterone, can increase SHBG concentration, leading to a decrease in free testosterone levels 3.
- Progesterone has also been shown to have a proinflammatory effect in healthy men, which may be related to its impact on testosterone levels 5.
- The use of progestins in combination with testosterone for hormonal male contraception has been found to suppress gonadotropin secretion, with varying effects on testosterone levels depending on the type and dose of progestin used 4.
Mechanism of Action
- Glucocorticoids, such as dexamethasone, have been found to directly inhibit gonadotropin-stimulated testosterone production in testicular cells, possibly by decreasing cAMP production and the activity of 17 alpha-hydroxylase 6.
- Progesterone has been shown to increase ex vivo testosterone production in the fathead minnow ovary, while decreasing the expression of progestin receptors and steroidogenic enzymes 7.
Key Findings
- Progesterone and progestins can have varying effects on testosterone levels, depending on the context and specific compounds used 3, 5, 4, 7.
- The relationship between progesterone and testosterone is complex and influenced by multiple factors, including SHBG binding, gonadotropin secretion, and steroidogenic enzyme activity 3, 4, 6, 7.