Hormone therapy for menopause

Photo of patient and doctor (PantherMedia / Robert Kneschke)

In most women, menopause symptoms like hot flashes aren't severe enough to need treatment. Short-term hormone therapy can provide relief in women with severe symptoms. Because of the associated risks, long-term therapy is no longer recommended.

During the years leading up to menopause (perimenopause), women’s bodies make less female sex hormones. They can then no longer become pregnant when they reach menopause. These natural changes are sometimes associated with symptoms like hot flashes (also called hot flushes), sleep problems and mood swings. The symptoms can vary in severity and usually go away on their own after a while.

A number of different treatment options are available for women who are experiencing typical menopause symptoms. But most of them haven't been proven effective. One of the better studied types of treatment is hormone therapy using a combination of estrogen and progestin (synthetic progesterone), or estrogen alone. This is currently the most effective treatment for hot flashes and sweats.

But what is true of all other drugs also applies to hormones: if they are effective, they will also have side effects and risks. These will depend on things like the type of hormone therapy and how long it's used for. Short-term treatment is usually enough.

Do hormones need to be replaced?

In the past, a lot of women took hormones during perimenopause and after menopause, sometimes for many years. Treatment with female sex hormones was commonly called hormone replacement therapy or “HRT.” The aim of this treatment was to replace the "missing" hormones. Because it was thought that this only involved putting something natural back into the body, people didn't really expect it to have any side effects.

But the idea that women live in a permanent state of hormone deficiency after menopause turned out to be wrong. The end of fertility has a biological purpose and protects older women from pregnancy, for example. So hormone therapy isn't a “natural replacement,” but a medical treatment. This means that the possible benefits and harms need to be weighed against each other.

Which hormones are used in hormone therapy?

The most common type of hormone therapy combines the hormones estrogen and progestin. Before menopause, both estrogen and progesterone are made in women’s bodies, mainly in the ovaries. Small amounts continue to be produced after the menopause, though – for example in fatty tissue.

Medications containing a combination of these hormones are taken to protect the membranes lining the uterus (womb). Treatment with estrogen alone has been found to very often cause abnormal cell growth in the lining of the uterus (womb). This can turn into endometrial cancer (in the lining of the womb) or uterine (womb) cancer in some women. Progestin can prevent the development of such growths.

Women who have had their womb removed (a hysterectomy) usually take estrogen only. This is called monotherapy, or unopposed estrogen therapy.

The synthetic hormone tibolone is another type of hormone therapy. Tibolone has a similar effect to both estrogen and progestin. It's not commonly prescribed in Germany. Research suggests that tibolone can relieve hot flashes, but not as effectively as treatment with a combination of estrogen and progestin can. Side effects include spotting (vaginal bleeding). Long-term treatment with tibolone could increase the risk of a relapse in women who have had breast cancer. It could also increase the risk of a stroke in women over the age of 60.

For a while now, “bio-identical” or “natural” hormones have been marketed more heavily. These are made semi-synthetically out of plant sources, and they have the same molecular structure as human hormones. They're not safer or more natural than conventional synthetic hormones. These hormones are sometimes available as pre-packaged products, but they can also be prepared by a pharmacist. Then they're often not subjected to quality control checks.

Estrogen and progestin combination products

There are now several dozen different hormone products for the treatment of menopause symptoms. They are available in the form of:

  • Tablets or capsules to be swallowed
  • Nasal sprays
  • Patches or gels applied to the skin
  • Injections
  • Creams, gels, tablets, suppositories or rings to be inserted into the vagina

Some forms of hormone products have to be used more regularly than others: For instance, oral tablets are usually taken every day, while patches will need to be changed once or twice a week. Vaginal rings need to be replaced about every three months.

When estrogens and progestins are combined, there are two possible approaches:

  • In “continuous” hormone therapy, women take both hormones every day.
  • In “cyclic” hormone therapy, they take only estrogens during one phase, and then take progestins as well as estrogens during the next phase.

Local hormone therapy

When hormone therapy is used directly in the vagina, women usually don't have to use progestin. Applying estrogen medications helps to build up the lining of the vagina, which has become thinner and drier. This medication can prevent pain during sex, for instance.

Local hormone therapy can also cause side effects such as spotting and breast tenderness.

Research summaries

How effective is hormone therapy?

Hot flashes

Many good-quality studies have shown that the number of hot flashes and sweats can clearly be reduced by treatment with either estrogen alone or with a combination of estrogen and progestin. Although they don't always go away completely, they are generally milder. Women who are woken at night by hot flashes are likely to sleep better again when on hormone therapy.

The studies that showed this effect lasted about 14 months on average. The women who participated took hormones orally (swallowed them). But other forms like patches are probably just as effective.

Overall, the studies found the following:

  • 66 out of 100 women who took a placebo (fake drug) still had hot flashes at the end of the study.
  • Only 20 out of 100 women who took hormone medication containing estrogen or a combination of estrogen and progestin still had hot flashes at the end of the study.

In other words, hormone therapy helped in 46 out of 100 women.

Influence on other symptoms

The studies also showed that hormone therapy can relieve other menopause symptoms such as sleep problems, mood swings or feeling down. And the hormones prevented pain during sex, regardless of whether the medication was swallowed or applied locally. The hormone therapy led to an overall improvement in the women's sex life and quality of life.

Influence on body weight

Studies have shown that weight often increases after middle age – regardless of whether someone takes hormones or not. The hormones don't cause weight gain, but they also don't stop it.

Short-term side effects

Combinations of estrogen and progestin commonly cause bleeding that is sometimes similar to menstrual bleeding (monthly period). Some women find this bleeding so bothersome that they stop hormone therapy. Hormone therapy can also cause breast tenderness.

What risks are associated with long-term hormone therapy?

Hormone medications have to be prescribed by a doctor. Originally, the main aim of hormone therapy was to relieve menopause symptoms. Then, in the 1980s, more and more people started to believe that hormone therapy could also protect women against illnesses that are more common in older age, such as heart disease. As a result, increasing numbers of women started taking hormones for longer and longer, even if they didn't have any menopause symptoms.

But scientific studies have since shown that long-term hormone therapy doesn't prevent most age-related health problems. On the contrary: It increases the risk of developing blood clots, strokes and breast cancer, for example. Some of these risks increase right at the start of hormone therapy, and others increase gradually as hormone therapy continues.

So if you have severe menopause symptoms, it's a good idea to carefully weigh the pros and cons of hormone therapy together with your doctor. If you decide to take hormones, the treatment should be as short as possible, using the lowest possible dose.

What happens when you stop taking hormones?

Surprisingly, there's currently no clear answer to this question. The effects might be different in different women: For instance, longer-term hormone therapy might help women through the hormonal transition, reducing the associated symptoms during that time. Then they won't have any symptoms when they stop hormone therapy. In other women, the hormone therapy might just delay these hormonal changes, so the symptoms will start up again after they stop hormone therapy.

The best evidence so far comes from a study involving about 16,000 women in the U.S. The women in this study took hormones for six years on average in order to treat menopause symptoms such as hot flashes. After they stopped, they were asked how they were doing. It turned out that more than half of the women had hot flashes and sweats again after stopping hormone therapy.

It's also possible to use such low doses of hormones that the symptoms are still noticeable but no longer a real problem. This gives women the opportunity to notice if their symptoms improve or go away altogether. Then they can talk with their doctor about stopping the hormone therapy.