Nausea, vomiting, headache, dizziness, hair loss, trouble sleeping, change in sexual desire, redness/swelling of the skin, change in skin color, and acne may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if you have any serious side effects, including: breast pain/enlargement, swelling of the feet/ankles (edema), weight gain, very slow/shallow/difficult breathing (possibly while sleeping), weakness, trouble urinating, increased urination (especially at night), mental/mood changes (such as depression, agitation, hostility), change in size/shape of the testicles, testicle pain/tenderness, stomach/abdominal pain, dark urine, yellowing of eyes/skin, fast/irregular heartbeat.
Get medical help right away if you have any very serious side effects, including: shortness of breath/rapid breathing, chest/jaw/left arm pain, unusual sweating, confusion, sudden dizziness/fainting, pain/swelling/warmth in the groin/calf, sudden/severe headaches, trouble speaking, weakness on one side of the body, sudden vision changes.
In patients with diabetes, especially those taking insulin, testosterone may decrease your blood sugar. Be prepared to treat low blood sugar while you are using this medication. Symptoms of low blood sugar include shakiness, nervousness, rapid pulse, and sweating. If you are experiencing these symptoms, consult your doctor. Your doctor may need to adjust your diabetes medications.
For males, in the very unlikely event you have a painful or prolonged erection lasting 4 or more hours, stop using this drug and get medical help right away, or permanent problems could occur.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.