Oral HRT Progestogens

Types of Oral Progestogens 

1. Micronised Progesterone (Utrogestan®)

• Derived from natural progesterone.

• Taken as capsules, either orally or vaginally.

• Benefits:

  • Considered to have a more favourable safety profile.

  • Little or no increase in breast cancer risk in the first 5 years of use, with a gradual increase if used longer.

  • Neutral effect on blood clotting, unlike some synthetic progestogens.

• Drawbacks:

  • Must be taken at bedtime as it can cause drowsiness.

  • Needs to be taken with food for best absorption.

2. Norethisterone

• A synthetic progestogen commonly used in combined HRT tablets.

• Benefits:

  • Effective at protecting the womb lining.

  • Widely available in standard HRT preparations.

• Drawbacks:

  • Associated with a slightly higher risk of breast cancer compared to micronised progesterone.

  • May cause side effects such as mood changes, headaches, or bloating.

3. Medroxyprogesterone Acetate (MPA)

• Another synthetic progestogen used in some combined HRT regimens.

• Benefits:

  • Effective in preventing endometrial thickening.

• Drawbacks:

  • Evidence suggests a higher association with breast cancer risk compared to micronised progesterone.

  • May increase risk of blood clots (VTE).

4. Dydrogesterone

• Less commonly prescribed in the UK but available in certain HRT combinations.

• Benefits:

  • Effective at protecting the womb lining.

  • Some evidence suggests a lower breast cancer risk compared to other synthetic progestogens.

• Drawbacks:

  • Limited availability compared to norethisterone or MPA.

Key Risks to Be Aware Of

• Breast cancer: Combined oestrogen and progestogen HRT is linked to a small increase in breast cancer risk, which rises with duration of use. The risk appears lower with micronised progesterone compared to synthetic progestogens.

• Blood clots (VTE): Oral progestogens may increase clot risk, particularly in women with other risk factors such as smoking, obesity, or a history of clotting disorders.

• Liver metabolism: Oral progestogens are processed by the liver, which may not be suitable for women with liver disease.

When Oral Progestogens May Be Recommended

• If you prefer a simple daily tablet.

• If you do not have contraindications such as a history of blood clots or liver disease.

• If you need a regimen that can be easily adjusted.

Duration of Use

Oral progestogens are usually prescribed for as long as HRT is needed.

Regular reviews are essential to reassess risks and benefits.

If side effects occur, alternatives such as vaginal preparations or the Mirena® coil may be considered.

Key Message

If you have a uterus and are prescribed HRT, you must remain on progestogen alongside oestrogen. Stopping progestogen is unsafe and increases your risk of womb cancer.

Different types of oral progestogen carry different risks, so your GP will help you choose the safest option for your health.