What is Premarin?
Estrogen is a female hormone produced in the ovaries, the production of which reduces considerably during menopause. This is the cause of menopausal symptoms. Premarin is an oral medication prescribed primarily to treat the symptoms of menopause associated with lowered production of estrogen, such as hot flushes and vaginal changes. It can also be prescribed as a prevention method against osteoporosis (bone loss). Premarin contains conjugated estrogens and belongs in a class of drugs called Estrogen Derivatives.

Prescription Required.
Product of Canada.
Shipped from Canada.
Prescription Required. | Product of Canada. | Shipped from Canada. |
What is Premarin?
Estrogen is a female hormone produced in the ovaries, the production of which reduces considerably during menopause. This is the cause of menopausal symptoms. Premarin is an oral medication prescribed primarily to treat the symptoms of menopause associated with lowered production of estrogen, such as hot flushes and vaginal changes. It can also be prescribed as a prevention method against osteoporosis (bone loss). Premarin contains conjugated estrogens and belongs in a class of drugs called Estrogen Derivatives.
Premarin is available in 0.3mg, 0.45mg, 0.625mg. 0.9mg, and 1.25mg strengths, and is taken as a tablet with a big glass of water, with or without food. Extended-release tablets are to be swallowed whole, and not crushed, chewed, or dissolved. Doing so will release all the drug at once and can increase the risk of side effects. The dosage prescribed is determined by the severity of your condition and adjusted according to how you respond to treatment. Always follow the directions given by your healthcare provider carefully.
Premarin is available in 0.3mg, 0.45mg, 0.625mg. 0.9mg, and 1.25mg strengths, and is taken as a tablet with a big glass of water, with or without food. Extended-release tablets are to be swallowed whole, and not crushed, chewed, or dissolved. Doing so will release all the drug at once and can increase the risk of side effects. The dosage prescribed is determined by the severity of your condition and adjusted according to how you respond to treatment. Always follow the directions given by your healthcare provider carefully.
Storage
Premarin tablets should be kept inside the blister pack. Premarin should be stored at room temperature, in a dry spot, and out of direct sunlight. It is not advised to store Premarin in the bathroom. Ensure Premarin is kept away from children and pets. Expired or unused product should not be flushed down the toilet or put down a drain, and instead should be properly discarded following the advice from your healthcare provider.
Side Effects
Common Side Effects
There are side effects associated with taking Premarin that you should discuss with your healthcare provider prior to starting the medication. These include:
- Asthenia
- Pain: abdominal, back, breast, headache
- Increased flatulence
- Nausea
- Mental health changes including depression
- Insomnia
- Endometrial hyperplasia
- Vaginal itching
- Vaginitis
Inform your healthcare provider if you experience any of these symptoms, particularly if they become severe or do not resolve on their own.
Serious Side Effects
On rare occasions, Premarin can cause serious side effects. These include pain or pressure in the chest, pain spreading to the jaw and shoulder region, queasiness, unusual sweating, sudden onset weakness, shortness of breath, confusion, unusual behaviour, trouble speaking, pain and swelling of legs, coughing up blood, sudden dizziness/fainting, vomiting, constipation, muscle weakness, or severe fatigue.
Experiencing a serious allergic reaction to Premarin is rare, however medical assistance should be sought if you experience a rash, itching/swelling (particularly of the face/tongue/throat), severe dizziness, or trouble breathing.
Experiencing any of these symptoms should be taken seriously, and medical help should be sought right away.
This is not an exhaustive list of possible side effects of Premarin use. If you have any concerns, ask your healthcare provider.
Warnings & Precautions
Consult your healthcare provider before taking this medication and let them know if you are allergic to the ingredients or have any other allergies. Ensure your healthcare provider is familiar with your medical history.
It is not advised to take Premarin if you have any of the following:
- Unusual vaginal bleeding
- History of breast or ovarian cancer
- History of heart attacks, stroke, or, or blood clots
- Have a bleeding disorder
- Think you may be pregnant
Estrogens should be prescribed at the lowest possible dose for the minimum period. To reduce the chance of cancer, it is recommended to take a progestin alongside estrogen for women with a uterus. Any unusual vaginal bleeding must be reported to your healthcare provider immediately while you are taking Premarin.
Do not share the medication with anyone else. Do not stop taking Premarin or alter your dosage without checking with your healthcare provider. Do not start taking Premarin unless it has been recommended and prescribed directly to you by a doctor. Do not take Premarin beyond its expiry date, or if the packaging is ripped or damaged. Dispose of the remaining medication responsibly.
Cardiovascular Disorders
The use of estrogen-alone therapy is associated with an increased risk of deep vein thrombosis and stroke, while the use of estrogen plus progestin is associated with an increased risk of pulmonary embolism, deep vein thrombosis, stroke, and heart attack. Premarin use should be discontinued immediately if any of these are suspected.
Endometrial Cancer
Estrogen use in women with a uterus has shown an increased risk of endometrial cancer. It is critical that all women taking Premarin are constantly monitored for any signs of unusual vaginal bleeding.
Visual Changes
There is a correlation between the use of estrogens and retinal vascular thrombosis. If you experience any visual abnormalities, including vision loss (partial or complete), estrogen use should be immediately discontinued.
Nursing Mothers
It is not advised to take Premarin while lactating. Studies have shown a reduction in breast milk quality and quantity associated with estrogen administration. Breast-feeding individuals should not take Premarin.
Pediatric Use
The safety of Premarin use in pediatric patients has not been established and is therefore not advised.
Pregnant or Planning to Become Pregnant
Do not take Premarin if you are pregnant or planning to become pregnant.
Overdose
If you suspect an overdose, call emergency services immediately. Overdose symptoms include nausea and vomiting, dizziness, feeling overly sleepy, breast tenderness and stomach pain.
Interactions & Contraindications
Drug-drug interactions can alter the effectiveness of medications or alter the risk of developing side effects from one or both drugs. It is important that you let your healthcare provider know all the drugs you use (prescription and non-prescription) before starting Premarin.
Use of estrogens in conjunction with smoking tobacco increases the risk of stroke, blood clots, high blood pressure, and heart attack, especially in women aged over 35 years. Inform your doctor if you intend on having surgery, or if you will be confined to a chair or bed for a long time (such as a long haul flight), as these conditions increase the risk of blood clots. This may warrant pausing the medication or you may need to take special precautions.
Be sure to tell your doctor if you are taking herbal medicines (e.g. St John’s Wort), epilepsy medication, antibiotics, thyroid medication, or corticosteroids. Avoid grapefruit and its juices as it can affect the mechanism of Premarin.
Premarin may cause melasma (blotchy patches on your skin). This effect may be exacerbated by sunlight, so ensure to limit your time in the sun. Avoid tanning booths and use sunscreen and UV protective clothing when outdoors.