Hormone therapy for menopause

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.

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 womb (uterus). Treatment with estrogen alone has been found to very often cause abnormal cell growth in the lining of the womb (the endometrium). 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 is 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 recurrence 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. So they're not safer or more natural than 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.

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.

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 locally-applied medication can prevent pain during sex, for instance. It can also reduce urinary incontinence (leaking urine) and overactive bladder symptoms.

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

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, compared to only
• 20 out of 100 women who had hormone therapy with estrogen or a combination of estrogen and progestin.

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.

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

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.

In the past, it was thought that hormone therapy prevents diseases that are more common in older age, such as heart disease. But scientific research has since shown that most age-related health problems can’t be prevented by long-term hormone therapy. On the contrary: This treatment increases the risk of developing blood clots, stroke and breast cancer, among other things.

Some risks associated with hormone therapy already increase shortly after starting the treatment, and other risks only increase gradually over time. This was the conclusion of a review of 22 studies with more than 43,000 participants in total. The biggest of the studies, involving about 27,000 participants, is known as the “Women’s Health Initiative Study (WHI).” The hormone therapy in this study was stopped earlier than originally planned, after about five to seven years, when it became clear that the treatment had more disadvantages than advantages. But the researchers still followed the participants for several years afterwards, to find out whether the treatment had any later effects.

The following table shows how common certain health problems are in women who have long-term hormone therapy after menopause. The figures were mostly taken from the findings of the “Women’s Health Initiative Study.”

Hormone therapy with a combination of estrogen and progestin was found to have the following disadvantages after eight years:

If women take a combination of estrogen and progestin for longer than five years, their risk of breast cancer will probably stay higher even after they stop hormone therapy. Also, one analysis showed that women who have long-term hormone therapy are more likely to develop dementia.

Women who only used estrogen didn't have a higher risk of breast cancer. But they had a similar increased risk of stroke and thromboembolism as women who used a combination of estrogen and progestin did.

The research suggests that long-term hormone therapy can prevent bone fractures. The following advantage was found after eight years:

Bone fractures occurred in

• 126 out of 1,000 women who had treatment with estrogen and progestin, and in
• 154 out of 1,000 women who didn't have hormone therapy (were given a placebo).

Some analyses of the studies also suggest that hormone therapy could lower the risk of bowel cancer somewhat.

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

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 some 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 the end of the therapy.

In one U.S. study involving more than 8,000 women, the participants took hormones for about six years on average in order to treat menopause symptoms such as hot flashes. After the treatment was stopped, more than half of the women had hot flashes and sweats again.

It is 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.