There are many types of different HRT. This leaflet addresses the use of oral estrogen-only hormone replacement therapy (HRT) (e.g. Premarin®, Estrofem®, Progynova®) which contain the female hormone, estrogen, to relieve bothersome symptoms of menopause. Learn how to use the medication, its common side effects, special precautions to watch out for, and more.

What is this medication for?

There are many types of different HRT. This leaflet addresses the use of oral estrogen-only hormone replacement therapy (HRT) (e.g. Premarin®, Estrofem®, Progynova®) which contain the female hormone, estrogen, to relieve bothersome symptoms of menopause. 

Symptoms of menopause include hot face, neck and chest (“hot flushes”), night sweats, vaginal dryness and low mood. The decrease in estrogen may also lead to a condition called osteoporosis, where the bones become thinner, weaker and easier to break. Using estrogen alone may cause abnormal thickening of the uterus (womb) lining – hence those with an intact uterus require an additional female hormone, progestogen, to prevent this. 

How should I take or use this medication?

• Do not stop taking your medication without checking with your healthcare professional.
• This medication should be taken after food.
• You should take one tablet daily without break, preferably at the same time every day.
• When a pack is finished, the next pack should be started without any break.
• If you have an intact uterus and are still menstruating, your doctor will prescribe a separate progestogen hormone as well to take for a specific duration (usually 10 – 14 days) each month. In this case, you will experience a withdrawal bleed (menses) after finishing the progestogen tablets.

What should I do if I forget to take or use this medication?

• Take the missed dose as soon as you remember. Then take your next dose at the usual time. Do not take two doses to make up for the missed dose.
• You may have vaginal bleeding or spotting if you forget to take more than one tablet. 

What precautions should I take when taking or using this medication?

This medication is NOT meant to be a birth control method and will not prevent you from getting pregnant.

Inform your healthcare professional if: 

• You are allergic to this medication or any of the other ingredients of this medication.
• You are pregnant, planning to become pregnant, or breastfeeding. 
• You are taking any other medications, including supplements, traditional medications and herbal remedies.
• You have a history of or current medical conditions such as liver problems, stroke, heart disease, blood clots, migraine headaches, epilepsy, diabetes mellitus or cancer.
• You are going for a surgery. You may need to stop taking HRT for a couple of weeks before the surgery.

What are some common side effects of this medication?

• Breakthrough bleeding and spotting 
  • May occur during the first few months of treatment or if doses are missed. If it continues after the first months of treatment, appears after some time during therapy, or continues after treatment has been stopped, ask your doctor for advice. 
• Mood changes 
  • Take medication at the same time every day to avoid huge changes in the hormone levels in your body, which can lead to mood changes.
• Breast tenderness, slight bloating or fluid retention 
• Nausea and vomiting
  • Take the medication after food to reduce these side effects.
• Headache
  • You may take Paracetamol to manage headaches. Do make sure that you are drinking enough water. 

Inform your doctor if these side effects become severe and bothersome.

What are some rare but serious side-effects that I need to seek medical advice immediately?

The symptoms of a drug allergy include one or more of the following: 

• Swollen face/eyes/lips/tongue
• Difficulty in breathing
• Itchy skin rashes over your whole body

Taking HRT increases a woman’s risk of developing blood clots and breast cancer. However, these are rare and the doctor would have evaluated and weighed its benefits over risks before making the recommendation. Please discuss with your doctor if you have any concerns.

• The symptoms of blood clot include one or more of the following: 
  • Any unusual sudden cough, breathlessness or difficulty in breathing
  • Severe pain in the chest which may reach the left arm
  • Severe pain in legs or swelling in either of your legs
  • Weakness or numbness in any part of your body
  • Change in your speech, including slurring of words
  • Change in your senses of hearing, smell or taste
  • Vision changes such as loss of vision/ blurred vision

It is also advisable to regularly check your breasts while you are on HRT.  If you notice any unusual changes, please see your doctor immediately. 

Other rare but serious side effects that you may or may not experience include:

• Unexpected, heavy or longer than usual menstrual bleeding
• Dark urine or light coloured stools, nausea, vomiting, loss of appetite, stomach pain, yellowing of your eyes or skin
• Bothersome mood changes

If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

What food or medication should I avoid when I take or use this medication?

Please inform your other healthcare professionals about the HRT you are taking if you are seeing them for other medical conditions.

• Some medications including antibiotics, antifungals and St John’s wort may affect how HRT works or be affected by HRT. Check with your healthcare professional if you want to take any other medicines, supplements or herbal products.
• If you see another healthcare professional, inform him that you are taking this medication before he prescribes any other medications.

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children. 

How do I throw away this medication safely?

Pack this medication into a black trash bag and seal it tightly before throwing into the rubbish chute or bin. 

What else should I know about this medication?

There are different types of hormone replacement therapy (HRT) available with different ways of using them. Some routines can be cyclical (sequential) or used daily (continuous). The type of HRT that you will be prescribed depends on different factors after careful consideration with your physician. 

If you want to find out more about the other types of HRT other than the one you are currently prescribed, please check with your health care provider. 

Disclaimer

Please take note that the above is not a complete list of all possible side effects. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on September 2024