Micronised Progesterone: What Every Woman on HRT Should Know

If you are taking hormone replacement therapy (HRT) and have a uterus, you need progesterone in addition to estrogen. Its role is to protect the lining of the womb from the excessive growth that could occur if estrogen were given on its own. In recent years there has been growing discussion of micronised progesterone, which is considered a more modern alternative to some synthetic progestins.

What is micronised progesterone?

Micronised progesterone is a bioidentical form of progesterone, which means it has the same molecular structure as the progesterone produced by a woman’s body. It is made from plant sources and, unlike some older synthetic progestins, is often better tolerated. In the Czech Republic it is best known under the name Utrogestan.

What are its benefits?

Among the most commonly cited benefits are:

• a bioidentical structure
• fewer side effects in some women
• a more favourable effect on mood for some users
• a mild sedative effect that can support sleep
• a favourable safety profile in terms of cardiovascular health

It is precisely this positive effect on sleep that is one of the reasons many women prefer micronised progesterone over synthetic alternatives.

How is it taken?

In women who are still menstruating or are in perimenopause, a sequential regimen is usually used. This means that estrogen is taken every day and progesterone only for part of the month, typically 12–14 days of each cycle. After progesterone is stopped, a bleed similar to a period usually follows.

After menopause, progesterone is most often taken every day, together with estrogen.

When should it be taken?

Micronised progesterone is recommended in the evening before sleep, roughly two hours after eating. Taking it with food increases its absorption and may increase the occurrence of side effects.

What are the possible side effects?

Like any medication, micronised progesterone can have side effects.

The most common are:

• drowsiness
• dizziness
• headaches
• bloating
• nausea
• irregular bleeding or spotting

These difficulties tend to be most pronounced in the first months of treatment and often gradually subside.

Is micronised progesterone safe?

Available studies suggest that micronised progesterone has a favourable safety profile. The data so far do not show an increased risk of stroke, blood clots or heart disease. In women using a combination of estrogen and micronised progesterone, no significant increase in the risk of breast cancer has been demonstrated in the first years of treatment.

Summary

Micronised progesterone is a bioidentical form of progesterone used in HRT. It protects the lining of the womb, is usually well tolerated, and in some women can contribute to better quality sleep. Although it is not suitable for every woman, it is an important part of modern hormonal treatment in perimenopause and menopause.