This medication is used in men who do not make enough of a natural substance called testosterone. Testosterone belongs to a class of drugs known as androgens. Testosterone helps the body to develop and maintain male sexual characteristics (masculinity), such as a deep voice and body hair. It also helps to maintain muscle and prevent bone loss, and is necessary for natural sexual ability/desire.
Testosterone may also be used in certain adolescent boys to cause puberty in those with delayed puberty.
This product should not be used in women.
How to use testosterone undecanoate intramuscular
Read the Medication Guide provided by your pharmacist before you start using this medication and each time you receive an injection. If you have any questions, ask your doctor or pharmacist.
This medication is given by injection into the buttock muscle as directed by your doctor. After the first dose, it is usually given 4 weeks later, then every 10 weeks. The dosage is based on your medical condition, testosterone blood levels, and response to treatment.
Use this medication regularly to get the most benefit from it. To help you remember, use a calendar to mark the days you will receive an injection.
Do not suddenly stop using testosterone if you have been using it regularly for a long time or in high doses. In such cases, your body will no longer make its own testosterone, and withdrawal reactions (such as tiredness, weakness, depression) may occur. To prevent withdrawal reactions, your doctor may reduce your dose gradually. Consult your doctor or pharmacist for more details, and report any withdrawal reactions right away.
Abnormal drug-seeking behavior is possible with this medication, and it is often misused for its muscle-enhancing effects. Using a higher dose, or using it more often or for a longer time than prescribed may increase serious side effects (such as increased risk for heart disease, stroke, liver disease, ruptured tendons/ligaments, improper bone development in adolescents). Properly stop the medication when so directed.
Tell your doctor if your condition does not improve or if it worsens.
See also Warning section.
Nausea, vomiting, headache, skin color changes, increased/decreased sexual interest, oily skin, hair loss, and acne may occur. Pain or redness at the injection site may also 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 when it is used at normal doses.
Tell your doctor right away if you have any serious side effects, including: breast swelling/tenderness, mental/mood changes (such as depression, agitation, hostility), unusual snoring or difficulty breathing during sleep, swelling hands/ankles/feet, symptoms of liver problems (such as loss of appetite, persistent nausea/vomiting, severe stomach/abdominal pain, yellowing eyes/skin, dark urine), trouble urinating, too frequent/prolonged erections, 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.
Rarely, males may have a painful or prolonged erection lasting 4 or more hours. If this occurs, get medical help right away, or permanent problems could occur.
This medication can decrease sperm production, an effect that may lower male fertility. Consult your doctor for more details.
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.