Premarin

Introduction

Written by Sarah Lewis, PharmD
Medically reviewed by Dena Westphalen, PharmD
Updated on July 28, 2023

Premarin (prem-uh-rin) is a brand-name medication prescribed for symptoms of menopause and other hormone-related conditions. Premarin belongs to a group of drugs called estrogens.

The Food and Drug Administration (FDA) has approved Premarin for:

• treating symptoms of menopause, such as hot flashes or vaginal dryness and thinning
• treating low estrogen when the ovaries don’t produce enough or have been removed
• managing symptoms of some types of breast or prostate cancer to help improve quality of life
• treating abnormal uterine bleeding due to a hormone imbalance
• preventing osteoporosis (bone thinning) that happens after menopause

These approved uses differ based on the form of Premarin your doctor prescribes.

This article doesn’t provide coupons for all forms of Premarin. To find coupons for Premarin vaginal cream, see this article.

Boxed warnings

Premarin has boxed warnings about the risks of certain cancers and risk of dementia. It also has a boxed warning about the risk of serious heart or blood vessel events, such as stroke and blood clots. Boxed warnings are the most serious warnings from the Food and Drug Administration (FDA).

For details, see the “Interactions and warnings for Premarin” section.

Common questions about Premarin

Below you’ll find answers to a few commonly asked questions about Premarin.

Is Premarin available as a generic?

No, Premarin isn’t available in a generic form. Premarin is an estrogen product called conjugated estrogens. There are estrogen products that are similar to Premarin. Some of them are available as generic medications, such as estradiol.

A generic medication is an identical copy of the active drug in a brand-name medication. (An active drug is the ingredient that makes a medication work.) Generics usually cost less than brand-name drugs. And they’re thought to be as safe and effective as the brand-name versions.

To learn more about estrogen products that are like Premarin, talk with your doctor or pharmacist.

For Premarin vaginal cream, how do you use the product?

There are two ways to use Premarin vaginal cream.

The first way is cyclical dosing. You insert the dose inside your vagina daily for 21 days. Then you take a break for 7 days of no treatment and start again.

The other way is twice weekly dosing. You insert the dose inside your vagina once per day on 2 days that are spaced apart. For example, one dose on Monday and one dose on Thursday.

Your doctor will let you know the best way for you to use Premarin vaginal cream. Follow the directions on your prescription. For questions about how to use Premarin vaginal cream, talk with your doctor.

How does Premarin work? And how long does it take to start working?

Premarin works by replacing the hormone estrogen that your body naturally makes. This helps relieve symptoms of having too little estrogen.

Estrogen levels will start to rise as soon as you start taking Premarin or using the vaginal cream. But it can take some time for your symptoms to get better. Usually, you will start to get relief from your symptoms within the first 4 weeks of treatment. But everyone responds differently. It may take up to 12 weeks to see the full effect of Premarin.

If you’d like to know more about this, talk with your doctor or pharmacist.

Uses of Premarin

The Food and Drug Administration (FDA) approves prescription drugs such as Premarin for certain conditions. Approved uses for Premarin are described below. These uses differ based on the form of Premarin prescribed.

Use for treating vaginal and vulvar conditions

Doctors may prescribe Premarin oral tablet or vaginal cream for treating certain vaginal or vulvar conditions. The medications are used for this purpose in adults. They’re usually prescribed as a long-term treatment. But doctors try to limit their use to the shortest duration possible.

With these vaginal and vulvar conditions, low levels of estrogen cause changes in vaginal tissues. This includes thinning, dryness, itching, and pain. In severe cases, fissures or splits in the tissue can happen. Replacing estrogen can help relieve these symptoms.

If you have vaginal or vulvar symptoms related to menopause without other symptoms of low estrogen, your doctor will likely prescribe the vaginal cream form of Premarin.

Premarin is prescribed together with a progestin if you still have a uterus.

Doctors may not prescribe Premarin oral tablet or vaginal cream in certain situations, such as when you have or may have any of the following:

• genital bleeding when the cause isn’t known
• certain types of cancer
• blood clots
• liver disease
• clotting disorders
• pregnancy

Use for treating vasomotor menopausal symptoms

Doctors may prescribe Premarin oral tablet for treating vasomotor menopausal symptoms. (These include hot flashes and night sweats.) It’s used for this purpose in adults. It’s usually prescribed as a long-term treatment. But doctors try to limit its use to the shortest duration possible.

With vasomotor menopausal symptoms, you may feel a sudden rush of heat or flushing. When this happens during the day, they’re called hot flashes. Hot flashes that happen at night are called night sweats. It isn’t clear exactly why these happen, but taking estrogen can help relieve them.

Premarin is prescribed together with a progestin if you still have a uterus.

Doctors may not prescribe Premarin oral tablet in certain situations, such as when you have or may have any of the following:

• genital bleeding when the cause isn’t known
• certain types of cancer
• blood clots
• liver disease
• clotting disorders
• pregnancy

Use for abnormal uterine bleeding

Doctors may prescribe Premarin injection* for treating abnormal uterine bleeding. It’s used for this purpose in adults. It’s usually prescribed as a short-term treatment.

With abnormal uterine bleeding, a hormone imbalance causes bleeding from the uterus that isn’t usual. This could be bleeding between periods or after periods have stopped. It could also be prolonged or excessive bleeding. Doctors will rule out any physical causes, such as uterine fibroids or uterine tumors, before prescribing Premarin.

Doctors may not prescribe Premarin injection in certain situations, such as when you have or may have any of the following:

• genital bleeding when the cause isn’t known
• certain types of cancer
• blood clots
• liver disease
• clotting disorders
• pregnancy

* This injection may be given either into your vein or into your muscle. Your doctor will recommend which option is best for your treatment.

Use for treating low estrogen level

Doctors may prescribe Premarin oral tablet for treating low estrogen levels. It’s used for this purpose in adults and in certain adolescents. It’s usually prescribed as a long-term treatment.

With low estrogen levels, the body doesn’t make enough estrogen. This can happen with the following conditions:

• hypogonadism (when the ovaries make little to no estrogen or progesterone)
• oophorectomy (when the ovaries have been removed)
• primary ovarian failure (when the ovaries stop working too early, before age 40 years)

Premarin is prescribed together with a progestin if you still have a uterus.

Doctors may not prescribe Premarin oral tablet in certain situations, such as when you have or may have any of the following:

• genital bleeding when the cause isn’t known
• certain types of cancer
• blood clots
• liver disease
• clotting disorders
• pregnancy

Use for palliative cancer treatment

Doctors may prescribe Premarin oral tablet for palliative cancer treatment. It’s used for this purpose in adults. It can be prescribed as a long-term or short-term treatment, depending on the need.

With palliative cancer treatment, the goal is to relieve symptoms and provide comfort to improve quality of life. It isn’t a curative treatment. Premarin may help relieve symptoms of metastatic breast cancer (breast cancer that has spread) or prostate cancer that needs androgens (male* hormones) to grow.

For females,* Premarin is prescribed together with a progestin if you still have a uterus.

Doctors may not prescribe Premarin oral tablet in certain situations, such as when you have or may have any of the following:

• genital bleeding when the cause isn’t known
• certain types of cancer
• blood clots
• liver disease
• clotting disorders
• pregnancy

* Sex and gender exist on spectrums. In this article, we use the terms “male” and “female” to refer to a person’s sex assigned at birth.

Use for preventing osteoporosis after menopause

Doctors may prescribe Premarin oral tablet to help prevent osteoporosis after menopause. It’s used for this purpose in adults. It’s usually prescribed as a long-term treatment. But doctors try to limit its use to the shortest duration possible.

With osteoporosis, the bones become less dense and bone mass decreases. This makes bones thin and more brittle. Having osteoporosis increases the risk of fractures and can cause changes in posture and height.

Premarin is prescribed together with a progestin if you still have a uterus.

Doctors may not prescribe Premarin oral tablet in certain situations, such as when you have or may have any of the following:

• genital bleeding when the cause isn’t known
• certain types of cancer
• blood clots
• liver disease
• clotting disorders
• pregnancy

Side effects of Premarin

Premarin may cause mild or serious side effects. More common mild side effects of Premarin and its serious side effects are listed below. This article doesn’t include all possible side effects of the drug. Side effects can vary based on your age, overall health, and any other medications you take.

To learn more about Premarin’s side effects, ask your doctor or pharmacist. You can also refer to the prescribing information for Premarin listed in the “Resources” section.

Mild side effects

More common mild side effects reported with some forms of Premarin are listed below. These side effects may differ based on the form of Premarin you take or use.

This article doesn’t include all possible mild side effects of the drug. To learn more about Premarin’s side effects based on the form, refer to the prescribing information for Premarin listed in the “Resources” section.

With many drugs, mild side effects may go away within a few days or a couple of weeks. If the side effects are bothersome, tell your doctor or pharmacist. They may be able to suggest ways to manage them.

Premarin oral tablet’s mild side effects include:

• abdominal pain
• breast pain
• passing gas
• increased vaginal discharge
• mild allergic reaction*

Premarin vaginal cream’s mild side effects include:

• breast pain
• headache
• increased vaginal discharge
• pelvic pain
• mild allergic reaction*

* For details about this side effect, see the “Interactions and warnings for Premarin” section.

Serious side effects

Serious side effects of Premarin are listed below. These side effects may differ based on the form of Premarin you take or use.

This article doesn’t include all possible serious side effects of the drug. To learn more about Premarin’s side effects based on the form, refer to the prescribing information for Premarin listed in the “Resources” section.

With many drugs, serious side effects are possible but not common. If you have serious side effects from this drug, call your doctor right away. If you’re having severe symptoms or a medical emergency, call 911 or a local emergency number.

In general, Premarin’s serious side effects include:

• fluid retention (swelling)
• gallbladder problems
• high blood pressure
• high or low calcium levels
• high triglyceride levels
• liver problems
• low thyroid hormone levels
• vision problems
• boxed warnings: risk of certain cancers, dementia, stroke, blood clots, and other serious heart or blood vessel events*
• severe allergic reaction*

* For details about this side effect, see the “Interactions and warnings for Premarin” section.

Interactions and warnings for Premarin

Below, you’ll find information about Premarin’s possible interactions and warnings.

Interactions of Premarin

Certain things may affect how a drug works. These include getting vaccines, consuming alcohol or certain foods, or taking the drug with other medications. This effect is called a drug interaction.

Before you take or use Premarin, ask your doctor to check for possible interactions. Be sure to tell them about any of the following you take or use:

• prescription or over-the-counter drugs
• vitamins, herbs, or supplements

To learn about drug-condition interactions, see the “Warnings for Premarin” section below.

Warnings for Premarin

Some people should not take or use Premarin, and others should take or use it cautiously.

Boxed warnings

Premarin has boxed warnings about the risk of certain cancers and risk of dementia. It also has a boxed warning about the risk of stroke, blood clots, and other serious heart or blood vessel events. Boxed warnings are the most serious warnings from the Food and Drug Administration (FDA).

To learn more about these warnings, read below. You can also talk with your doctor or pharmacist.

Risk of certain cancers. Taking Premarin increases the risk of endometrial cancer (cancer of the lining of the uterus). The longer you take the drug, the greater the risk. If you still have a uterus, taking a progestin with Premarin can help decrease this risk. But this combination may increase the risk of breast cancer. Due to this risk, doctors usually prescribe Premarin at the lowest effective dose for the shortest duration of time necessary.

Symptoms of endometrial cancer may include pelvic pain, bleeding after menopause, or bleeding or discharge not related to your period.

If you experience any of these symptoms, tell your doctor. They’ll likely recommend testing to find the cause.

Risk of dementia. Taking Premarin, either alone or with a progestin, may increase the risk of developing dementia, especially if you are age 65 years or older. Premarin should not be used to prevent dementia. Due to this risk, doctors usually prescribe Premarin at the lowest effective dose for the shortest duration of time necessary.

Symptoms of dementia may include problems with thinking, memory, and communication.

If you experience any of these symptoms, tell your doctor. They’ll likely recommend testing to find the cause.

Risk of stroke, blood clots, and other serious heart or blood vessel events. Taking Premarin increases the risk of heart attack, stroke, and blood clots, including deep vein thrombosis (DVT) and pulmonary embolism (PE). (A DVT is a blood clot that forms in a deep vein, often in your lower leg. A PE is a blood clot that forms in your lungs.) Premarin should not be used to prevent heart attack, stroke, or blood clots. Due to this risk, doctors usually prescribe Premarin at the lowest effective dose for the shortest duration of time necessary.

Symptoms of these conditions can vary, but they may include:

• chest pain or discomfort
• leg pain, coolness, or discoloration
• shortness of breath
• trouble speaking
• drooping on one side of the face
• weakness or numbness on one side of the body

If you experience any of these symptoms, seek emergency medical care or call 911.

Other warnings

Premarin could cause harm to people with certain health conditions. This effect is called a drug-condition interaction. Other factors can also affect whether Premarin is a safe option for you. These warnings may differ based on the form of Premarin you take or use.

Ask your doctor about specific warnings for Premarin, and be sure to tell your doctor about your:

• current health, including any allergies to medications
• past health conditions or surgeries

Allergic reaction

Premarin can cause an allergic reaction in some people. Severe allergic reactions are rare but possible.

If you’ve had an allergic reaction to Premarin or any of its ingredients, your doctor will likely not prescribe Premarin. They can tell you about medications that are safer options for you.

A mild allergic reaction may cause the following symptoms:

• skin rash
• itchiness
• flushing (temporary warmth, redness, or deepening of skin color)

A severe allergic reaction may cause the following symptoms:

• swelling under your skin, usually in your hands, feet, eyelids, or lips
• swelling of your mouth, throat, or tongue, which can cause breathing problems

If you have an allergic reaction to Premarin, call your doctor right away. If you have severe symptoms, call 911 or a local emergency number.

Overdose of Premarin

If you take Premarin by mouth or use Premarin, you should not take or use more Premarin than your doctor prescribes. For some drugs, doing so may lead to harmful effects or overdose.

If you think you’ve taken or used too much Premarin, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have concerning symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.

Pregnancy or breastfeeding and Premarin

Information about Premarin and pregnancy and breastfeeding is described below.

Premarin and pregnancy

Premarin should not be taken or used during pregnancy. If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking or using this medication. Your doctor may suggest birth control options to use during treatment with Premarin.

Premarin and breastfeeding

Premarin should not be taken or used while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before taking or using this medication. Your doctor may recommend other ways to feed your child during treatment with Premarin.

What to ask your doctor

This article describes Premarin’s uses and side effects, ways to save on cost, and more. Let your doctor know if you have questions about Premarin or would like more details about it.

Here’s a list of some possible questions you may want to ask your doctor:

• What are the risks of using Premarin?
• Am I at higher risk of side effects or other problems from Premarin compared with other people?
• What alternative medications are available to treat my condition?

Resources

• Food and Drug Administration. (2023). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm
• Premarin (conjugated estrogens) tablets, USP for oral use. (2017). https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/004782s176lbl.pdf
• Premarin (conjugated estrogens) vaginal cream. (2017). https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/020216s083lbl.pdf
• Premarin intravenous (conjugated estrogens, USP) for injection. (2021). https://labeling.pfizer.com/showlabeling.aspx?id=467

Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.