When is treatment with hormones considered?

Photo of a woman at the doctor's (PantherMedia / Wavebreakmedia Premium)

Female sex hormones play an important role in fibroid growth. This makes it possible to shrink fibroids with hormone therapy. The hormones can be used to relieve symptoms or to help prepare for surgery.

Some hormone therapies can be used to temporarily relieve heavy menstrual bleeding and period pain. These treatments can also shrink fibroids, but they can't make them disappear completely. Hormones are usually only used for a limited amount of time because of the risk of side effects. But the therapy only works for as long as it is used, so the fibroids may grow again once it is stopped.

Hormone therapy is most commonly used to shrink fibroids before surgery. It may also be an option for women just before menopause – or for women who, for whatever reason, can’t have surgery.

The different hormone therapies include:

  • GnRH analogues (injections or nasal sprays)
  • Progestins (hormonal intrauterine device and progestin-only pills)
  • Progestin and estrogen combinations (combination birth control pills)
  • Ulipristal acetate (the drug used in the “morning-after pill”)

GnRH analogues

GnRH analogues are artificially produced hormones. They inhibit the production of estrogen in the ovaries. Because estrogen makes it easier for fibroids to grow, using GnRH analogues can temporarily slow their growth or cause them to shrink in size. GnRH analogues are usually injected into skin or muscle tissue once a month. They are also available in the form of depot (slow-release) injections that last for three months, and a nasal spray for daily use.

GnRH analogues aren't suitable for long-term use because of their side effects. They can increase the risk of osteoporosis (loss of bone mass) if they are used for longer than about one year. They also reduce the body’s production of estrogen so much that it isn't possible to get pregnant while using them. When treatment with GnRH analogues is stopped, the ovaries start functioning normally again and estrogen levels return to normal levels. Then it's possible to get pregnant again.

During this treatment, it's important to have the size of the fibroids checked by a doctor and keep an eye on whether your symptoms change. This also includes watching for side effects, because estrogen deficiency may cause problems.

How effective are GnRH analogues?

GnRH analogues make fibroids stop growing or shrink, which may reduce menstrual bleeding and period pain. The treatment can improve anemia, which lowers risks during surgery. But not all women benefit from these hormone analogues: About half don’t notice any improvement in their symptoms.

GnRH analogues are usually only used for less than six months. The goal is often to shrink the fibroids before a surgical procedure. If the fibroids are smaller, then the cuts made during surgery to remove them can be smaller too.

What are the possible side effects?

GnRH analogues often cause side effects that are very similar to problems associated with menopause, including:

  • Hot flashes: in about 45 out of 100 women
  • Sweating: in about 35 out of 100 women
  • Vaginal infections: in about 10 out of 100 women

Hormonal intrauterine devices

Hormonal intrauterine devices (IUDs) are inserted into the womb (uterus) and can remain there for up to five years. Also known as hormonal coils, they are normally used for contraception. They contain artificial hormones called progestins which are similar to the female sex hormone progesterone. Progesterone prevents the lining of the womb from building up during the menstrual cycle. Hormonal IUDs continuously release progestins, which also prevent the lining of the womb from building up.

Hormonal IUDs are only suitable for treating fibroids that aren’t too big. Larger fibroids may change the shape of the womb, making it impossible to insert an IUD. And because they have a contraceptive effect, IUDs are also not a good idea for women who would like to become pregnant.

How effective are hormonal IUDs?

IUDs can’t reduce the size of the fibroids, so they won’t relieve symptoms like pain and cramps. But because the artificial hormones stop the lining of the womb from building up, they can help to lower the amount of blood lost during menstruation and help prevent anemia. People who have anemia usually feel tired and beat.

It can help to keep a diary when starting treatment so that you can keep track of things like how often you still have heavy periods, whether other symptoms improve or whether you experience any side effects. These notes can help your doctor to assess how effective the treatment is.

What are the possible side effects?

Hormonal IUDs may cause various side effects, including acne, spotting (vaginal bleeding between periods), mood swings and breast tenderness. These kinds of side effects are usually more common during the first few months of treatment than later on. Overall, they affect about 10 out of 100 women who use hormonal IUDs. These IUDs are rejected by the body in about the same number of women. Using a hormonal IUD carries a certain risk: It is estimated that they cause damage to the womb in up to 1 out of 1,000 women.

Birth control pills: Progestin-only pills and combination pills

Birth control pills contain either a combination of the hormones estrogen and progestin (combination pill), or only progestin (mini pill). Both kinds can reduce the flow of menstrual blood, making them an option for women whose main symptom is heavy periods. Uninterrupted use of the combination birth control pill usually causes menstrual periods to stop completely over time. Because using the pill in this way – with only rare breaks or none at all – hasn’t been approved in Germany, it is considered to be “off-label” use. This means that some health insurers may not cover the costs.

The pill may cause side effects such as water retention, head aches and breast tenderness. It can also increase the risk of blood clots (thrombosis), especially in older women and women who smoke. It'is not clear how effective the pill is in relieving fibroid symptoms, or how it compares to other treatments. There isn’t enough good-quality research on using birth control pills to treat fibroid symptoms.

Ulipristal acetate

Ulipristal acetate (trade name: Esmya) is best known as being the drug used in the “morning after pill.” These pills can be taken after unprotected sex to prevent an unwanted pregnancy. Ulipristal acetate has also been approved at a lower dose for use in treating uterine fibroids. It is the only selective progesterone receptor modulator (SPRM) that has been approved for this purpose in Germany. It blocks the effect of the female sex hormone progesterone. Like estrogen, progesterone also promotes fibroid growth. 

Because of the risk of life-threatening liver damage, ulipristal acetate was taken off the market throughout the European Union in March 2020 for the treatment of uterine fibroids. It will remain unavailable until a risk assessment conducted by the European Medicines Agency (EMA) has been completed. Current treatments should be stopped and no new treatments may be started.

This warning does not affect the one-time use of ulipristal acetate as a "morning after pill." There is no new evidence of particular risks for that use.