Before using leuprolide, tell your doctor or pharmacist if you are allergic to it; or to similar drugs (such as histrelin, triptorelin); or of any other allergies. This product may contain inactive ingredients (such as benzyl alcohol), which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: diabetes, heart disease (such as heart attack), stroke, high cholesterol, mental/mood problems (such as depression), seizures.

In adults, leuprolide may weaken your bones and increase your risk for bone loss (osteoporosis) if used for a long time. Before using this medication, tell your doctor or pharmacist if you have osteoporosis or if you have any of the following risk factors for osteoporosis: long-term alcohol use, smoking, family history of osteoporosis and broken bones, use of certain medications (for example, corticosteroids such as prednisone, certain anti-seizure drugs such as phenytoin).

In adults, leuprolide may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.

The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using leuprolide, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).

Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using leuprolide safely.

This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Older adults may be more sensitive to the side effects of this drug, especially QT prolongation (see above).

This medication can affect fertility in males. Ask your doctor for more details.

This medication must not be used during pregnancy. It may harm an unborn baby. It is important to prevent pregnancy while using this medication. Consult your doctor for more details and to discuss using reliable forms of non-hormonal birth control (such as condoms, diaphragm with spermicide) while using this medication. If you become pregnant or think you may be pregnant, tell your doctor right away.

It is unknown if leuprolide passes into breast milk. Because of the possible risk to the infant, breastfeeding is not recommended while using this medication. Consult your doctor before breastfeeding.