Kyzatrex (testosterone undecanoate) is an oral medication used to treat adult males with a condition called hypogonadism, meaning they have low or no testosterone. It comes as a convenient capsule that's typically taken by mouth twice a day (once in the morning and once in the evening). The most common side effect of this medication is high blood pressure. Kyzatrex (testosterone undecanoate) is available as a brand-name medication only; there are currently no generic versions on the market.
Low testosterone levels from certain medical conditions
Testosterone is a hormone that your body makes. It's the main sex hormone in males and is responsible for developing male sex organs. Testosterone also plays a role in maintaining other body functions, such as muscle growth, sex drive, and sperm production.
Some males have low testosterone because of certain medical conditions. Kyzatrex (testosterone undecanoate) works by raising testosterone in the body to healthy levels.
Kyzatrex (testosterone undecanoate) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Risk factors: High blood pressure | Heart problems | High blood sugar | Obesity
Kyzatrex (testosterone undecanoate) can cause high blood pressure that raises the risk of serious problems, such as heart attack, stroke, or sudden cardiac (heart-related) death. This is more likely to occur in people who already have heart problems or have risk factors for heart problems. Your provider will check your blood pressure before you begin taking Kyzatrex (testosterone undecanoate) and periodically after you start or if there's a change in your dose. They'll probably also ask you to check your blood pressure regularly at home. If you develop high blood pressure, your provider might ask you to start blood pressure medication. If your blood pressure still remains high, you might need to stop taking Kyzatrex (testosterone undecanoate).
Let your provider know and get emergency help right away if you experience symptoms of heart problems, such as:
Stroke: sudden numbness or weakness on one side of your body, sudden confusion, trouble speaking, difficulty maintaining balance
Heart attack: dizziness, tiredness, tightness or pain in the chest, heartburn, trouble breathing, sweating, anxiety
Kyzatrex (testosterone undecanoate) can cause a high red blood cell count. This can raise the risk for blood clots to develop that can possibly lead to strokes and heart attacks. Your provider will order blood tests every 3 months to check that your red blood cell count is healthy. Get emergency help right away if you have chest pain, cold sweats, left arm pain, difficulty breathing, trouble walking or speaking, or weakness on one side of the body, as you might have to stop taking the medication.
Kyzatrex (testosterone undecanoate) can cause life-threatening blood clots in your legs or lungs. Symptoms of a blood clot in the legs include leg pain, swelling, or redness. Symptoms of a blood clot in the lungs include difficulty breathing or chest pain. Let your provider know if you have any of these symptoms and seek medical help right away, as you might have to stop the medication.
Risk factors: Taking more Kyzatrex (testosterone undecanoate) than prescribed | Taking Kyzatrex (testosterone undecanoate) with other testosterones
Kyzatrex (testosterone undecanoate) is a controlled substance because it has a risk of misuse, dependency, and addiction, especially if you use higher doses than prescribed or use it with other testosterones. Misusing Kyzatrex (testosterone undecanoate) can cause serious heart and mental health problems. These problems can include heart attack, heart failure, stroke, liver problems, depression, delusions, hallucinations, and aggression. Dependency is when you rely on the medication to function normally and have withdrawal symptoms, such as depression, trouble sleeping (insomnia), and lowered sex drive, when you lower the dose or stop the medication suddenly.
Continued misuse of Kyzatrex (testosterone undecanoate) can lead to addiction. Addiction can cause behaviors, such as taking a higher dose than prescribed, spending a lot of time trying to get the medication when there are problems with availability, prioritizing medication use over other responsibilities, and having trouble stopping the medication even if you want to stop. Remember to take Kyzatrex (testosterone undecanoate) as prescribed to lower the risk of misuse, dependency, and addiction.
Risk factors: History of enlarged prostate
Taking Kyzatrex (testosterone undecanoate) can worsen certain symptoms in people with an enlarged prostate, or benign prostatic hyperplasia (BPH). Let your provider know if you experience any changes in your urinary routine, such as more urination at night, feeling like you need to urinate more often or immediately, trouble urinating, accidentally urinating, or urinating slowly.
Kyzatrex (testosterone undecanoate) can also raise your risk of prostate cancer. Your provider might have you get occasional blood tests and physical check-ups before and during treatment. Kyzatrex (testosterone undecanoate) isn't recommended if you have prostate cancer because it might worsen your cancer.
Using certain forms of testosterone, such as methyltestosterone and testosterone enanthate intramuscular injection, for long periods of time can cause life-threatening liver problems. While Kyzatrex (testosterone undecanoate) isn't known to cause liver problems, it's important to be aware of this risk. Let your provider know if you're experiencing stomach pain, light-colored stools, dark urine, or if your skin or the whites of your eyes turn yellow. You might need to stop the medication.
Risk factors: Taking higher doses of Kyzatrex (testosterone undecanoate)
Kyzatrex (testosterone undecanoate) can lower the amount of sperm you make, which can make it harder for you to have a baby. This is more likely to happen when using higher doses of Kyzatrex (testosterone undecanoate). Because this might become permanent, talk to your provider if you're trying to have a baby.
Risk factors: History of heart, liver, or kidney conditions | Taking other medications that cause swelling like corticosteroids
Taking Kyzatrex (testosterone undecanoate) can cause your body to hold onto more salt and water, which can lead to swelling in your legs or arms and sudden weight gain. This is more likely to happen if you're also taking other medications that cause swelling, such as corticosteroids (e.g., prednisone, methylprednisolone (Medrol)). Swelling can be more serious in people with heart, liver, or kidney conditions. Talk to your provider if you have any of these symptoms because you might need to stop Kyzatrex (testosterone undecanoate) or take other medications (e.g., water pills or diuretics) to help with this problem.
Risk factors: History of sleep apnea | History of obesity | History of lung problems
Kyzatrex (testosterone undecanoate) can worsen symptoms in people who have breathing problems while they sleep. This is more likely to happen to people who also have a history of obesity or lung conditions. Talk to your provider if you experience more daytime sleepiness or if your partner notices that you stop breathing in your sleep more often.
Risk factors: History of cancer | Taking other medications that cause high calcium in the blood
Kyzatrex (testosterone undecanoate) can raise calcium levels in the blood, especially in people with cancer. Too much calcium can lead to muscle weakness, thirst, bone pain, and kidney problems such as frequent urination. During treatment with Kyzatrex (testosterone undecanoate), your provider might have you get regular blood tests to make sure your calcium levels are within the normal range.
Source: DailyMed
Side effects that you should report to your care team as soon as possible:
Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):
Works well to replace testosterone in your body
Conveniently comes as a capsule that you swallow
Dose can be adjusted based on your testosterone levels
Can raise your cholesterol and triglyceride levels
Can cause high blood pressure, which can raise your risk of serious heart conditions
Requires regular blood tests to check testosterone and nutrient levels
You'll typically take Kyzatrex (testosterone undecanoate) twice daily, in the morning and the evening, with food. Taking Kyzatrex (testosterone undecanoate) with food helps it absorb into your system better, which will give you a better response from the medication.
Follow your provider's instructions when taking Kyzatrex (testosterone undecanoate). This medication is only FDA approved for treating low testosterone in males with specific medical conditions. Using it differently can result in severe side effects like heart issues, stroke, depression, hallucinations, and delusions.
Kyzatrex (testosterone undecanoate) can often cause the breast area in males to become bigger, painful, or tender. This might continue throughout treatment. Let your provider know if this becomes bothersome.
Regularly check your blood pressure while using Kyzatrex (testosterone undecanoate), since the medication can raise your blood pressure. If your blood pressure becomes too high, your healthcare provider might suggest adding a blood pressure medication to lower it. Your provider might have you stop taking Kyzatrex (testosterone undecanoate) if it becomes difficult to manage your blood pressure.
If you have diabetes, talk to your provider about whether you need to check your blood sugar more often while taking Kyzatrex (testosterone undecanoate). This medication can lower your blood sugar, especially if you take insulin. Make sure you know how to treat low blood sugar if you experience symptoms like shakiness, sweating, fast heartbeat, and confusion. Also contact your provider if this happens because you might require changes to your medications.
If you're taking blood thinners, like warfarin (Coumadin), let the provider who's managing your blood thinner treatment know that you're taking Kyzatrex (testosterone undecanoate). Taking Kyzatrex (testosterone undecanoate) together with blood thinners can cause you to bleed more easily. Your provider might monitor your blood-clotting time more often when you're taking this medication. Tell your provider if you experience bleeding that takes longer to stop, bruising, blood in your urine, or dark stools, as the dose of your blood thinner might need to be adjusted.
Because Kyzatrex (testosterone undecanoate) can cause high blood pressure, this raises your risk for heart attacks and strokes. Many prescription and over-the-counter medications can also raise your blood pressure. Before starting any new medications, it's important to check with your provider or pharmacist about any interactions.
The typical starting dose is 200 mg by mouth twice daily (once in the morning and once in the evening), with food. Your provider might adjust your dose based on the testosterone levels in your blood. The typical maintenance dose ranges from 100 mg once daily to 400 mg twice daily.
Currently pregnant
Low testosterone levels not caused by anatomical or genetic causes (for example, age-related low testosterone)
Low testosterone levels from certain medical conditions
Low testosterone levels from certain medical conditions
Low testosterone (hypogonadism)
By signing up, I agree to GoodRx's Terms and Privacy Policy, and to receive marketing messages from GoodRx.
Marius Pharmaceuticals. (2023). Kyzatrex- testosterone undecanoate capsule, liquid filled [package insert]. DailyMed.
McBride, J. A., et al. (2016). Testosterone deficiency in the aging male. Therapeutic Advances in Urology.
MedlinePlus. (2022). Hypogonadism.
White, W. B., et al. (2021). Effects of the oral testosterone undecanoate Kyzatrex™ on ambulatory blood pressure in hypogonadal men. Journal of Clinical Hypertension.
You and Your Hormones. (2020). Testosterone.
Research prescriptions and over-the-counter medications from A to Z, compare drug prices, and start saving.