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Generic name: testosterone oraltes-TOS-ter-one ]
Drug class: Androgens and anabolic steroids

Medically reviewed by Judith Stewart, BPharm. Last updated on Aug 22, 2023.

What is Kyzatrex?

Kyzatrex (testosterone) is a liquid filled capsule used to treat symptoms of low testosterone in men who have hypogonadism (a condition in which the body does not produce enough natural testosterone).

Kyzatrex is used only for men with low testosterone levels caused by certain medical conditions, including disorders of the testicles, pituitary gland, (a small gland in the brain), or hypothalamus (a part of the brain) that cause hypogonadism.

Your doctor will order certain lab tests to check your testosterone levels to see if they are low before you begin to take Kyzatrex.

Kyzatrex should not be used treat the symptoms of low testosterone in men who have low testosterone due to aging ('age-related hypogonadism').

Testosterone is a hormone produced by the body that contributes to the growth, development, and functioning of the male sexual organs and typical male characteristics. Kyzatrex works by replacing testosterone that is normally produced by the body.

It is not known if Kyzatrex is safe or effective in children younger than 18 years old. Improper use of this medicine may affect bone growth in children.


You should not be treated with Kyzatrex if you have prostate cancer, male breast cancer, or low testosterone levels due to getting older.

Kyzatrex can increase your blood pressure, which can increase your risk of heart attack, stroke, or death. You may need to stop using this medicine or start taking blood pressure medication.

Kyzatrex should not be used to enhance athletic performance.

Before taking this medicine

You should not take Kyzatrex if you are allergic to testosterone, or if you have:

To make sure Kyzatrex is safe for you, tell your doctor if you have ever had:

Kyzatrex is not approved for use in women.

It may be harder for you to get a woman pregnant while you are using this medicine.

Using testosterone may increase your risk of developing prostate cancer. Ask your doctor about your individual risk.

How should I take Kyzatrex?

Take Kyzatrex as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose.

Your doctor will perform tests to make sure this medicine is the right treatment for you.

Kyzatrex capsules are available in three strengths of 100 mg, 150 mg, and 200 mg.

Take Kyzatrex by mouth twice daily. Take one time in the morning and take one time in the evening. If your dose is 100 mg daily, just take one time in the morning.

You will need frequent blood tests and your blood pressure will need to be checked often. Your next dose may be delayed based on the results.

Do not keep leftover medicine. Just one dose can cause death in someone using it accidentally or improperly. Ask your pharmacist about a drug take-back program.

Testosterone may be habit-forming. Misuse can cause addiction or death. Keep the medication where others cannot get to it. Selling or giving away this medicine is against the law.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking Kyzatrex?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Kyzatrex side effects

Get emergency medical help if you have signs of an allergic reaction to Kyzatrex: hives, difficult breathing, swelling of your face, lips, tongue, or throat.

Kyzatrex can increase your blood pressure, which can increase your risk of heart attack, stroke, or death. You may need to stop using this medicine or start taking blood pressure medication.

Kyzatrex may cause serious side effects. Call your doctor at once if you have:

Common Kyzatrex side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Kyzatrex?

Tell your doctor about all your other medicines, especially:

This list is not complete. Other drugs may interact with testosterone, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.


Active ingredient: testosterone undecanoate.
Inactive ingredients: DL-alpha-tocopheryl acetate (Vitamin E), phytosterol esters, polyoxyl 40 hydrogenated castor oil and propylene glycol monolaurate. The ingredients of the gelatin capsule shells are gelatin, glycerin, purified water, sorbitol, and titanium dioxide.


Marketed by Marius Pharmaceuticals: Raleigh, NC 27615, USA.

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Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Kyzatrex only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.