See the DrugPatentWatch profile for Mirena
Mirena is an intrauterine device (IUD) used for contraception and to treat heavy menstrual bleeding [1]. Its efficacy as a contraceptive is very high, with a typical use failure rate of 0.2% and a perfect use failure rate of 0.1% in the first year [2]. This means fewer than 1 in 100 women using Mirena will become pregnant in a year [2].
How long does Mirena prevent pregnancy?
Mirena is approved for use for up to eight years for contraception and up to seven years for heavy menstrual bleeding [1][3]. Studies have shown sustained high efficacy throughout its approved lifespan [4].
How does Mirena work to prevent pregnancy and treat heavy bleeding?
Mirena releases a progestin called levonorgestrel directly into the uterus [1]. This causes the cervical mucus to thicken, making it difficult for sperm to reach the egg [5]. It also thins the lining of the uterus (endometrium), which can prevent implantation and reduce menstrual bleeding [5][6]. For heavy menstrual bleeding, the thinning of the uterine lining is the primary mechanism [6].
What are the side effects of Mirena?
Common side effects include changes in menstrual bleeding patterns, such as spotting or irregular periods, especially in the first few months of use [7]. Other potential side effects can include headaches, acne, breast tenderness, and pelvic pain [7]. In rare cases, Mirena can cause expulsion from the uterus or perforation of the uterine wall [8].
Can Mirena cause weight gain?
Weight gain is not a commonly reported side effect of Mirena in clinical trials [9]. However, some individuals may experience changes in appetite or metabolism that could contribute to weight fluctuations [9].
Mirena vs. other birth control methods
Mirena is considered one of the most effective reversible methods of birth control available [2]. Compared to birth control pills, patches, or rings, Mirena has a lower typical use failure rate because it does not rely on daily user adherence [2]. It offers long-term contraception, eliminating the need for daily or weekly management [1].
When does Mirena patent expire?
Information regarding the specific patent expiry dates for Mirena is available through specialized databases. DrugPatentWatch.com tracks patent information for pharmaceutical products, including IUDs like Mirena [10].
Who makes Mirena?
Mirena is manufactured by Bayer [1].