Advertisement

Generic Name:

synthetic-conjugated-estrogens, Oral tablet

All Brands

  • Cenestin (Discontinued)
A discontinued drug is a drug that has been taken off the market due to safety issues, shortage of raw materials, or low market demand.
SECTION 1 of 4

Highlights for synthetic-conjugated-estrogens

Oral tablet
1

Conjugated synthetic estrogens is an oral drug used after menopause to treat moderate to severe hot flashes and dryness, itching, and burning in and around the vagina.

2

Your dose depends on the condition that’s being treated. The standard dose for hot flashes is 0.45 mg or more taken one time per day. For vaginal dryness, itching, and burning, the standard dose is 0.3 mg taken one time per day.

3

Common side effects include headache, stomach or abdominal cramps, bloating, breast pain, nausea, vomiting, irregular vaginal bleeding or spotting, hair loss, high blood pressure, fluid retention, liver problems, enlargement of noncancerous tumors of the uterus (fibroids), high blood sugar levels, and vaginal yeast infection.

4

In rare cases, conjugated estrogen therapy can cause severe side effects. These include uterine or breast cancer, heart attack, stroke, and blood clots in your legs or lungs.

5

Let your doctor know if you plan to have surgery or be on bed rest. This can increase your risk for blood clots. Tell your doctor if you have any of these symptoms: unusual vaginal bleeding, new breast lumps, changes in your vision or speech, sudden severe headache, severe pain in your legs or chest, or swollen lips, tongue, and face. These may be signs of serious side effects.

IMPORTANT INFORMATION

FDA warning

This drug has a Black Box Warning. This is the most serious warning from the Food and Drug Administration (FDA). A black box warning alerts doctors and patients to potentially dangerous effects.

Uterine cancer warning. Estrogens increase your chance of uterine cancer. Taking progestin with estrogen may lower your risk. Your doctor should closely monitor you when you're taking synthetic conjugated estrogens. Tell your doctor about any unusual vaginal bleeding right away. Vaginal bleeding after menopause may be a warning sign of cancer.

You may have a higher risk if you take the drug long-term or at high doses. Your risk may not be as high if you take this medicine for less than a year. You may still have a higher risk for uterine cancer for several years after you stop treatment with conjugated estrogens.

Heart problems warning. You shouldn’t use estrogens with or without progestin to prevent heart disease, heart attacks, or strokes. Using estrogens may increase your chance of a heart attack, stroke, and blood clots in your legs or lungs. If you develop any heart problems, you should stop taking this medication right away.

Breast cancer warning. If you take conjugated estrogens with progestin, you have an increased risk of breast cancer. The risk may decrease 5 years after you stop treatment. You may also have a higher risk of having an abnormal mammogram if you take estrogen and progestin. You should perform monthly breast self-examinations and see your doctor for breast checkups as often as they suggest.

Dementia warning. Using estrogens with progestin may increase your risk of dementia.

Synthetic conjugated estrogens with or without progestin should be taken at the lowest effective dose and for the shortest amount of time. You and your healthcare provider should talk regularly during treatment about whether you still need the drug. 

Other medications

Tell your doctor about all prescription and over-the-counter drugs, herbs, and supplements that you’re taking. Synthetic conjugated estrogens may interact with other medications.

Gallbladder disease

Postmenopausal women who take estrogen have a higher chance of needing gallbladder surgery.

Fluid retention

Estrogen can cause fluid retention and swelling. This could make some types of heart and kidney conditions worse.

What is synthetic conjugated estrogens?

Synthetic conjugated estrogens is a prescription drug. It’s available as an oral tablet.

This drug may be used as part of a combination therapy with progestin. That means you need to take it with other drugs.

Why it's used

Conjugated synthetic estrogens is used after menopause to replace estrogen that the body no longer makes. It’s used to decrease moderate to severe hot flashes and vaginal dryness.

How it works

Synthetic conjugated estrogens is a mixture of man-made estrogens from a plant source. It belongs to a class of drugs called estrogen replacement therapy.

More Details

How it works

Synthetic conjugated estrogens is a mixture of man-made estrogens from a plant source. It belongs to a class of drugs called estrogen replacement therapy.  A class of drugs refers to medications that work similarly. They have a similar chemical structure and are often used to treat similar conditions.

Estrogens are hormones made by a woman’s ovaries. Estrogens are responsible for developing and maintaining the female reproductive system and secondary sexual characteristics.

The ovaries normally stop making estrogens when a woman is 45–55 years old. This drop in estrogen levels causes menopause (the end of monthly menstrual periods).

When estrogen levels start dropping, some women have uncomfortable symptoms. These include warmth in the face, neck, and chest or sudden feelings of heat and sweating (“hot flashes”) and vaginal dryness that can cause itching and burning.

In some women, the symptoms are severe and estrogen replacement with synthetic conjugated estrogens is needed.

Advertisement
SECTION 2 of 4

synthetic-conjugated-estrogens Side Effects

Oral tablet

Most Common Side Effects

The most common side effects that occur with conjugated synthetic estrogens include:

  • headache

  • stomach or abdominal cramps

  • bloating

  • breast pain

  • nausea

  • vomiting

  • irregular vaginal bleeding or spotting

  • hair loss

  • high blood pressure

  • fluid retention

  • liver problems

  • enlargement of noncancerous tumors of the uterus (fibroids)

  • high blood sugar levels

  • vaginal yeast infection

If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious Side Effects

If you experience any of these serious side effects, call your doctor right away. If your symptoms are potentially life threatening, or if you think you’re experiencing a medical emergency, call 9-1-1.

  • breast cancer. Symptoms include:

    • breast lumps
  • blood clots. Symptoms include:

    • feeling of warmth or pain in your leg
    • shortness of breath
    • chest pain
    • changes in vision
  • dementia

  • gallbladder disease. Symptoms include:

    • severe stomach pain
    • chest pain
    • heartburn
    • nausea and vomiting
    • fever
    • chills
    • tender stomach
  • stroke. Symptoms include:

    • changes in speech or vision
    • severe headaches
  • ovarian cancer. Symptoms include:

    • vaginal bleeding
    • pelvic pain
    • pain during sexual intercourse
    • unusual vaginal discharge
  • heart attack. Symptoms include:

    • chest pain
  • uterine cancer. Symptoms include:

    • unusual vaginal bleeding
  • dizziness and faintness

  • vomiting

  • liver problems. Symptoms include:

    • yellowing of the whites of your eyes or skin (jaundice)
  • high calcium blood levels due to breast cancer or bone metastases. Symptoms include:

    • confusion
    • fatigue
    • irregular heart rate (arrhythmia)
  • changes in vision caused by a blood clot (retinal thrombosis). Symptoms include:

    • double vision
    • migraine headaches  
Pharmacist's Advice
Clinical Associate Professor, University of Illinois at Chicago College of Pharmacy

Synthetic conjugated estrogens doesn’t cause drowsiness.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.
SECTION 3 of 4

synthetic-conjugated-estrogens May Interact with Other Medications

Oral tablet

Synthetic conjugated estrogens can interact with other medications, herbs, or vitamins you might be taking. That’s why your doctor should manage all of your medications carefully. If you’re curious about how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Note: You can reduce your chances of drug interactions by having all of your prescriptions filled at the same pharmacy. That way, a pharmacist can check for possible drug interactions.

Food interactions

Grapefruit juice may increase the level of synthetic conjugated estrogens in your body. This may cause an increase in side effects.

Medications that might interact with this drug

Anticonvulsants
  • phenobarbital
  • carbamazepine

These medicines might reduce the level of synthetic conjugated estrogens in your body. This means that it won’t work as well to treat your condition.

Antiviral drug
  • ritonavir

This medicine might increase the level of synthetic conjugated estrogens in your body. This may cause more side effects.

Azole antifungal
  • ketoconazole
  • itraconazole

These medicines might increase the level of synthetic conjugated estrogens in your body. This may cause more side effects.

Macrolide antibiotics
  • erythromycin
  • clarithromycin

These medicines might increase the level of synthetic conjugated estrogens in your body. This may cause more side effects.

Tuberculosis drug
  • rifampin

This medicine might reduce the level of synthetic conjugated estrogens in your body. This means that it won’t work as well to treat your condition.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.
Synthetic conjugated estrogens warnings
gallbladder disease
People with gallbladder disease

Use caution when taking synthetic conjugated estrogens if you have gallbladder disease. They can cause or worsen your gallbladder disease. You may need surgery to treat the gallbladder problems.

high blood pressure
People with high blood pressure

Synthetic conjugated estrogens can increase blood pressure levels. Your blood pressure should be monitored regularly while you’re taking these drugs. Your doctor may increase the dose of your high blood pressure medicines.

high triglyceride levels
People with high triglyceride levels

Synthetic conjugated estrogens can increase triglyceride levels. This can lead to swelling of the pancreas (pancreatitis) and other problems. If you have high triglyceride levels, you should consider other treatments in place of synthetic conjugated estrogens.

liver problems
People with liver problems

Synthetic conjugated estrogens might not be broken down well if your liver doesn’t work well. If you have a history of jaundice with estrogen therapy or pregnancy, use synthetic conjugated estrogens with caution. If the jaundice happens again, you should stop taking the medicine.

hypothyroidism
People with hypothyroidism

Use caution if you have hypothyroidism and are taking synthetic conjugated estrogens. Estrogens might decrease the effectiveness of your thyroid medicine. Your doctor might give you a higher dose of thyroid medicine. Your thyroid function should be monitored throughout treatment.

asthma
People with asthma

Estrogen can cause asthma to flare up. If you have asthma, use caution when taking this medication.

diabetes
People with diabetes

Estrogen can raise your blood sugar levels. This can cause your diabetes control to get worse. If you have diabetes, use caution when taking this medication.

epilepsy
People with epilepsy (seizures)

Estrogen can cause a flare-up of epilepsy. If you have seizures, use caution when taking this drug.

People with lupus

Estrogen can cause a flare-up of lupus. If you have lupus, use caution when taking this drug.

vaginal bleeding
People with vaginal bleeding

If you have vaginal bleeding, synthetic conjugated estrogens may make it worse. Vaginal bleeding after menopause may be a sign of uterine or endometrial cancer.

cancer
People with certain cancers

Synthetic conjugated estrogens may increase the chance of getting certain types of breast, uterine, or endometrial cancers. If you currently have or have a history of these types of cancer, you shouldn’t take this drug. It may worsen your cancer.

stroke or heart attack
People with a history of a stroke or heart attack

Synthetic conjugated estrogens can increase your chance of another stroke or heart attack. You should talk to your doctor before you take this drug if you have a history of heart problems.

blood clots
People with blood clots

Synthetic conjugated estrogens can cause blood clots. This drug shouldn’t be used if you have a blood clot in your leg (deep vein thrombosis or DVT) or lung (pulmonary embolism) or if you have a history of these problems.

heart failure or kidney problems
People with heart failure or kidney problems

If you have a condition that can be worsened by increased fluid in the body, use caution when taking this drug. Estrogens increase fluid in the body (fluid retention). You should be monitored for signs of worsening heart or kidney conditions if you take this medicine.

endometriosis
People with endometriosis who’ve had hysterectomy

If you’ve had a hysterectomy and are treated with synthetic conjugated estrogens alone, you have an increased risk of endometrial cancer if you still have endometriosis. You should take progestin with your conjugated estrogen therapy.

low blood calcium
People with low blood calcium levels

Conjugated estrogens can cause low calcium levels if your parathyroid doesn’t work well.

pregnant women
Pregnant women

Synthetic conjugated estrogens is a category X pregnancy drug. Synthetic conjugated estrogens should never be used during pregnancy.

Tell your doctor if you’re pregnant or plan to become pregnant.

breastfeeding
Women who are breast-feeding

Synthetic conjugated estrogens can decrease the quantity and quality of breast milk. It may also pass into breast milk.

for seniors
For seniors

Seniors may be more likely to develop dementia, stroke, or invasive breast cancer when using synthetic conjugated estrogens.

for children
For children

The safety and effectiveness of synthetic conjugated estrogens haven’t been established in people younger than 18 years of age.

contact with drug
Contact with drug

Don’t share this medication with anyone else even if they have the same symptoms as you. It may harm them.

call doctor
When to call the doctor

Tell your doctor if you’re supposed to be on bed rest or plan to have surgery, or if you have tests done that say you have high calcium blood levels.

allergies
Allergies

Synthetic conjugated estrogens can cause a severe allergic reaction. Symptoms include:

  • swelling of your face and tongue (angioedema)
  • trouble breathing
  • stomach pain
  • vomiting

Don’t take synthetic conjugated estrogens if you’ve ever had a severe allergic reaction to estrogens or any of its components. If an allergic reaction occurs, stop the medicine and seek medical help right away. Using it again could be fatal (cause death).

SECTION 4 of 4

How to Take synthetic-conjugated-estrogens (Dosage)

Oral tablet

Your dose, form, and how often you take it will depend on:

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

What are you taking this medication for?

Treatment of moderate to severe hot flashes after menopause

Brand: Cenestin

Form: Oral tablet
Strengths: 0.3 mg, 0.45 mg, 0.625 mg, 0.9 mg, and 1.25 mg
Adult dosage (ages 18 years and older)
  • The starting dose is 0.45 mg taken one time per day.
  • Your doctor may change your dose based on how you respond to the drug.
Child dosage (ages 0–17 years)

This medicine hasn’t been studied in children and shouldn’t be used in people under the age of 18 years.

Warnings

  • If you have a uterus and take synthetic conjugated estrogens, you should also take progestin to reduce your risk of endometrial cancer.
  • If you don’t have a uterus, you don’t need to take progestin.
  • Synthetic conjugated estrogens (with or without progestin) should be used at the lowest effective dose for the shortest amount of time.
  • Your dose should be reassessed (every 3–6 months) to determine if you still need to be treated with this drug.
  • If you have a uterus, you’ll need to be checked for cancer if you have any abnormal vaginal bleeding.

Treatment of moderate to severe vaginal dryness, itching, and burning after menopause

Brand: Cenestin

Form: Oral tablet
Strengths: 0.3 mg, 0.45 mg, 0.625 mg, 0.9 mg, and 1.25 mg
Adult dosage (ages 18 years and older)

The normal dose is 0.3 mg taken one time per day.

Child dosage (ages 0–17 years)

This medicine hasn’t been studied in children and shouldn’t be used in people under the age of 18 years.

Warnings

  • If you have a uterus and take synthetic conjugated estrogens, you should also take progestin to reduce your risk of endometrial cancer.
  • If you don’t have a uterus, you don’t need to take progestin.
  • Synthetic conjugated estrogens (with or without progestin) should be used at the lowest effective dose for the shortest amount of time.
  • Your dose should be reassessed (every 3–6 months) to determine if you still need to be treated with this drug.
  • If you have a uterus, you’ll need to be checked for cancer if you have any abnormal vaginal bleeding.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always to speak with your doctor or pharmacist about dosages that are right for you.
Pharmacist's Advice
Clinical Associate Professor, University of Illinois at Chicago College of Pharmacy

Synthetic conjugated estrogens comes with serious risks if you don’t take it as prescribed.

If You Don’t Take It at All or Skip or Miss Doses

If you don’t take synthetic conjugated estrogen as prescribed, your hot flashes or vaginal dryness, itching, or burning may not get better.

If You Take Too Much

If you take too much synthetic conjugated estrogens, you might have the following symptoms:

  • nausea
  • vomiting
  • vaginal bleeding

If you take too much, call your healthcare provider or the poison control center right away.

What to Do If You Miss a Dose

If you miss a dose, take it as soon as possible. If it’s almost time for your next dose, skip the missed dose and take your next dose at its normally scheduled time.

Don’t take two doses at the same time to try to make up for the missed dose. This could result in toxic side effects.

How to Tell If the Drug Is Working

You may be able to tell if the drug is working if you have fewer hot flashes, less severe hot flashes, and less itching, dryness, and burning in and around your vagina.

Synthetic conjugated estrogens is a short-term drug treatment.

It should be used for the shortest amount of time possible.

Important considerations for taking synthetic conjugated estrogens
take with or without food
You can this drug with or without food
timing
Take this drug at about the same time every day
do not crush or cut
You can’t crush or cut the oral tablet
storage
Store this drug from 68–77°F (20–25°C)
See Details
refillable
Prescription is refillable
travel
Travel
See Details
clinical monitoring
Clinical monitoring
See Details
your diet
Your diet
See Details
not usually stocked
Not every pharmacy stocks this drug, so call ahead

Store this drug from 68–77°F (20–25°C)

Don’t freeze synthetic conjugated estrogens. 

Keep it away from light and high temperatures.

Keep your drugs away from areas where they could get wet, such as bathrooms. Store this drug away from moisture and damp locations.

Travel

When traveling with your medication:

  • Always carry your medication with you, such as in your carry-on bag.
  • Don’t worry about airport X-ray machines. They can’t hurt your medication.
  • You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled box with you.
  • Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.

Clinical monitoring

To check if your medicine is working, your doctor will see how you respond to this drug.

Your doctor may do certain blood tests before starting and during treatment to make sure that the drug is safe for you to take. Your doctor may check:

  • vaginal bleeding
  • blood pressure
  • body weight
  • blood clots
  • changes in your breasts or uterus
  • gallbladder condition
  • vision changes
  • heart function
  • estrogen levels
  • cholesterol levels
  • blood calcium levels
  • blood sugar levels
  • thyroid function
  • kidney function
  • liver function
  • pelvic exam
  • breast exam
  • breast X-ray (mammogram)

Your diet

Synthetic conjugated estrogens interacts with grapefruit juice. You shouldn’t drink grapefruit juice while taking this medication.

Are there any alternatives?

There are several medications in this class and other medicines that can be used to treat hot flashes or vaginal irritation. Some may be more suitable for you than others. Talk to your doctor about possible alternatives.


Show Sources

Content developed in collaboration with University of Illinois-Chicago, Drug Information Group

Medically reviewed by Creighton University, Center for Drug Information and Evidence-Based Practice on August 20, 2015

Disclaimer: Healthline 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 other 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.
Advertisement
Advertisement
Advertisement