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Understanding hormones’ role in IUDs

So what is a levonorgestrel-releasing intrauterine system? The name conjures up something very complicated and intimidating but nothing can be further from the truth! Levonorgestrel-releasing intrauterine system, also called LNG-IUS, is a very fancy, scientific way for referring to hormonal IUDs!

What is an IUD?

IUDs are small, soft, plastic t-shaped devices that are inserted through the cervix and placed in the uterus to prevent pregnancy. The arms of the t-shape hold the IUD in place at the top of the uterus and block the sperm from entering the uterus.

Most birth control devices such as the pill, patch and levonorgestrel-releasing intrauterine system contain and call upon the sex hormones, estrogen and progesterone, to help the body prevent pregnancy.

HormONal IUDs

The levonorgestrel-releasing intrauterine system instead contains a type of progestin called levonorgestrel, a synthetic form of the hormone progesterone, which is slowly released into the uterus. The pill and patch contain progestin as well. But, in the levonorgestrel-releasing intrauterine system, progestin is released slowly and gradually keeping hormone levels steadier and lower than the pill.

The levonorgestrel, or progestin, thickens the cervical mucus inhibiting sperm from entering the uterus, thins the lining of the uterus making it harder for an egg to implant in the uterus and inhibits ovulation (the release of an egg from the ovary). All good things when you are trying to avoid getting pregnant! The hormone progestin also decreases the heavy painful bleeding and cramping associated with other IUDs on the market!

Unlike the pill or patch, the levonorgestrel-releasing intrauterine system does not contain estrogen, which can cause anxiety, irritability, headaches, fluctuations in blood sugar levels, water and salt retention and the dreaded weight gain! I personally have had very bad experiences with the pill and literally felt out of sorts, anxious, bloated and so terrible that my husband practically begged me to go off of them!


If you are considering using a levonorgestrel-releasing intrauterine system, you probably will want to learn more about how the hormones work and what side effects you might have. 

Progesterone, actually a precursor to estrogen, prevents water retention, serves as a natural antidepressant and creates a calming effect on the body. It should be noted that when women use progestin, the synthetic version of progesterone, some believe that it blocks the production of progesterone — occasionally leading to slight weight gain, headaches, increased blood pressure, acne, depression, breast tenderness and decrease in sex drive. These symptoms tend to come less frequently than when using the pill or patch but if you experience any severe symptoms, contact your doctor immediately. If you have not had problems with hormones in the past, more than likely you will not with the levonorgestrel-releasing intrauterine system.

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