From the Guidelines
Mirena, a levonorgestrel-releasing intrauterine device, has minimal effects on estrogen and testosterone levels, making it a suitable option for women who cannot use estrogen-containing contraceptives or are concerned about hormonal imbalances. The primary mechanism of Mirena is to release a small amount of levonorgestrel locally in the uterus, which thins the uterine lining and prevents pregnancy without significantly affecting systemic hormone levels 1. Regarding estrogen levels, Mirena may cause a slight decrease in some women, but this effect is typically localized to the uterus and does not significantly impact overall estrogen levels 1. For testosterone, Mirena generally has little to no significant impact on circulating testosterone levels in most women, as it does not contain androgens or anti-androgens that could affect testosterone levels 1. Some users might experience slight hormonal fluctuations during the first few months after insertion as the body adjusts to the device, but these usually stabilize over time. It is essential to note that Mirena causes fewer systemic hormonal effects than many other hormonal contraceptives because it works primarily at the uterine level, making it a good option for women who want to minimize hormonal side effects. If you're concerned about hormonal effects or are experiencing symptoms that might be related to hormone imbalance while using Mirena, consult with your healthcare provider, as individual responses can vary and other factors might be involved. Key points to consider when using Mirena include:
- Minimal effects on estrogen and testosterone levels
- Localized action in the uterus
- Suitable for women who cannot use estrogen-containing contraceptives
- Fewer systemic hormonal effects compared to other hormonal contraceptives
- Potential for slight hormonal fluctuations during the first few months after insertion.
From the Research
Effect of Mirena on Estrogen Levels
- The study 2 found that six months after Mirena placement, estradiol (E2) levels were 45.50 ± 7.13 pg/mL and 42.91 ± 8.10 pg/mL in the study and control groups, respectively, with no significant differences between the two groups.
- There is no direct evidence from the other studies on the effect of Mirena on estrogen levels.
Effect of Mirena on Testosterone Levels
- The study 3 found that levonorgestrel, the progestin released by Mirena, can displace testosterone from sex hormone binding globulin (SHBG), potentially leading to a slight increase in free testosterone levels.
- However, the study 3 also found that the decrease in serum SHBG following treatment with levonorgestrel was more important in increasing free testosterone levels.
- The study 4 discussed the role of testosterone in menopausal hormone treatment, but did not specifically address the effect of Mirena on testosterone levels.
- There is limited direct evidence on the effect of Mirena on testosterone levels, and more research is needed to fully understand this relationship.