Which women need Progesterone in HRT?

If you still have a womb (i.e have not had a hysterectomy), you need to also take a form of progesterone as part of your HRT. This is because taking estrogen alone when you have a womb can increase the thickness of the womb lining which can sometimes cause the cells to become cancerous. Taking a form of progesterone protects against this thickening effect of estrogen

 

Can Progesterone be used alone in HRT?

Although the most common use of progesterone in HRT is to modulate the effects of estrogen on the womb, it can also be used on its own to help with vasomotor symptoms (hot flushes and night sweats) and sleep disturbance.

Micronised Progesterone has a mild sedative effect, which is why it’s best taken at night-time. Many women report improved sleep when they take it.

There have been some small studies that have shown beneficial effects of progesterone-only treatment for vasomotor symptoms. These effects usually need doses of around 300mg, which is slightly higher than the doses when it is used alongside estrogen.

Unfortunately, no study has yet shown a significant improvement in mood or other symptoms. It also doesn’t have the same long-term health benefits of reduced risk of osteoporosis, fracture and heart disease that estrogen provides. 

 

How is the Progesterone in HRT given?

Most of the types of progesterone available in HRT are synthetic forms which are known as progestogens. These come as oral tablets or in the form of a progestogen releasing coil placed inside your womb. 

There is also a bio-identical form available that contains micronised progesterone - it is called Utrogestan and is a capsule that can be taken orally or vaginally.

Micronised progesterone is associated with lower risks, including breast cancer risk and also lower rates of adverse side effects.

 

Tablets

There are tablets that contain just progestogen and there are also tablets that contain both estrogen and progestogen.

 

Progestogen-only tablets

• Provera – contains medroxyprogesterone (fully funded)
• Primolut - contains norethisterone (fully funded)

 

Combinations tablets

(all contain norethisterone and estradiol)

• Kliogest (higher dose estrogen and continuous progestogen) part funded
• Kliovance (lower dose estrogen and continuous progestogen) part funded
• Trisequens (cyclical progestogen) part funded

 

Capsules

• Utrogestan – contains micronised progesterone –  (fully funded)

 

 Intrauterine Device

• Mirena Coil – contains levonorgestrel – funded (but insertion costs are not funded)

 

What is the safest way to take Progesterone in HRT?

The safest type of progesterone is Micronised Progesterone which is available in New Zealand in the capsule Utrogestan. This is a Bio-identical Progesterone (for more information see here). It has the same molecular structure as the progesterone we naturally produce in our body and is derived from the Mexican Wild Yam – a root vegetable

 

Taking Micronised progesterone is associated with LOWER risks of breast cancer compared to taking synthetic types of progesterone.

 

How is Utrogestan taken?

It can be taken orally or inserted into the vagina.

When taken orally, it is best taken at night on an empty stomach. It often has a mild sedative effect which many women say helps improve their sleep.

 

For more information on micronised progesterone/Utrogestan see here

 

What is Cyclical or Sequential HRT?

This is recommended for women who have had at least one period in the last one year (i.e. they are Perimenopausal).

‘Cyclical’ or ‘Sequential’ HRT means only taking the progesterone for 12 to 14 days each month. This is to allow your womb to have a period/bleed.

If a woman who is perimenopausal takes progesterone everyday, this can sometimes lead to erratic and irregular bleeding. Cyclical dosing helps prevent this and gives the woman control over when the bleeding will occur.

Cyclical HRT means you have to remember to take progesterone on some days and not others. We usually prescribe the progesterone for 2 weeks every month – so you take it for 2 weeks, then stop it for 2 weeks, then repeat.

Some women find cyclical dosing difficult to remember and so there is a tablet called Trisequens that automatically switches from combined tablets (that contain estrogen and progestogen) to estrogen only tablets. The different type of tablets are different colours and it means you just follow the pack and take a tablet everyday.

The disadvantage of this combined tablet is the progesterone component is a synthetic one and not bio-identical.  

 

What is Continuous HRT?

This is for women who have not had a period for one year or longer (ie. They are Post-Menopausal)

‘Continuous’ HRT means you do not have a break from the progesterone to allow a period/bleed to happen.

You take the progesterone in a constant way.

For Provera tablets and oral Utrogestan capsules – this means a dose everyday.

If however, you use the vaginal route for the Utrogestan, you use it on alternate days (as you only need half the oral dose)

 

How does the Mirena coil work?

This needs to be inserted into your womb. The procedure is simple, relatively painless and can be done either with your GP (if available at your practice), Family Planning Clinics or privately at the Adelpha clinic. It is also possible to have local anaesthetic or sedation to make the procedure more comfortable.  

The Mirena coil provides enough progestogen to protect the lining of the womb from the thickening effect of the estrogen component of HRT.

It is also a very effective method of contraception, so is useful for perimenopausal women, as pregnancy can still occur during this stage.

If you have very heavy, painful or erratic periods, the Mirena usually improves this and can often stop periods altogether.

It can be used for up to 5 years as part of HRT before it needs replacing. 

If a woman with a Mirena has become post-menopausal (which will need to be diagnosed with blood tests as the Mirena often masks/stops periods), she can have it removed at 5 years and be switched onto tablets or vaginal progesterone for her HRT instead. 

 

What are the possible side effects of Progesterone?

Progestogens can have unwanted side-effects such as bloating, mood swings and breast tenderness. These often settle within the first few months.

For some women, these side effects are quite severe and this is known as Progesterone Intolerance. See here for more information on this.

If the side effects continue, we try a different type and/or a different delivery mode for the progesterone.

For example, side effects are less likely with bio-identical progesterone (Utrogestan) than with synthetic progestogen (medroxyprogesterone and norethisterone).

If oral utrogestan causes side effects, they are often improved by using half the dose and inserting the capsule vaginally instead.

For some women, the Mirena coil offers the least side effects, because the progestogen is released directly into the womb.

 

References:

Dolisky SN, Christina CM, Sheehan SS, et al.. Efficacy of progestin-only treatment for the management of menopausal symptoms: a systematic review. Menopause 2020; 28: 217-224.

Hitchcock CL, Prior JC. Oral micronized progesterone for vasomotor symptoms—a placebo-controlled randomized trial in healthy postmenopausal women. Menopause. 2012;19(8):886-893

Schüssler P, Kluge M, Yassouridis A, et al. Progesterone reduces wakefulness in sleep EEG and has no effect on cognition in healthy postmenopausal women. Psychoneuroendocrinology. 2008;33(8):1124-1131