skip to Main Content
KYZATREX Bottles Transparent

Frequently Asked Questions

KYZATREX is designed to simplify testosterone replacement therapy for your patients. Find answers to some of the most common questions so you can confidently introduce KYZATREX to your practice.


KYZATREX is an FDA-approved oral testosterone for men who have low or no testosterone levels due to certain medical conditions.

KYZATREX is a controlled substance (CIII) because it contains testosterone. It is not known if KYZATREX is safe or effective in males younger than 18 years old. Improper use may affect bone growth in children. KYZATREX is not meant for use by women.

How does KYZATREX work?

KYZATREX is an oral formulation of testosterone undecanoate (TU) that utilizes lymphatic absorption to bypass first-pass metabolism and drive uptake. With the use of phytosterols as GRAS excipients to drive absorption, KYZATREX was designed for clinical efficacy and safety.¹

Who is eligible for KYZATREX?

KYZATREX (testosterone undecanoate) capsules, CIII, is indicated for testosterone replacement therapy in adult males for conditions associated with a deficiency or absence of endogenous testosterone:

  1. Primary hypogonadism (congenital or acquired): testicular failure due to conditions such as cryptorchidism, bilateral torsion, orchitis, vanishing testis syndrome, orchiectomy, Klinefelter syndrome, chemotherapy, or toxic damage from alcohol or heavy metals. These men usually have low serum testosterone concentrations and gonadotropins (follicle-stimulating hormone (FSH), luteinizing hormone (LH)) above the normal range.
  2. Hypogonadotropic hypogonadism (congenital or acquired): gonadotropin or luteinizing hormone-releasing hormone (LHRH) deficiency, pituitary-hypothalamic injury from tumors, trauma, or radiation. These men have low serum testosterone concentrations but have gonadotropins in the normal or low range.

Limitations of Use

Safety and efficacy of KYZATREX in males less than 18 years old have not been established.


KYZATREX is Schedule III controlled substance due to potential risk for abuse of testosterone.
KYZATREX labeling includes a boxed warning for increased blood pressure.

KYZATREX can cause blood pressure (BP) increases that can increase the risk of major adverse cardiovascular events (MACE), including non-fatal myocardial infarction, non-fatal stroke and cardiovascular death.

Before initiating KYZATREX, consider the patient’s baseline cardiovascular risk and ensure BP is adequately controlled.

Periodically monitor for and treat new-onset hypertension or exacerbations of pre-existing hypertension and re-evaluate whether the benefits of KYZATREX outweigh its risks in patients who develop cardiovascular risk factors or cardiovascular disease on treatment.

Due to this risk, use KYZATREX only for the treatment of men with hypogonadal conditions associated with structural or genetic etiologies.


KYZATREX is contraindicated in patients with carcinoma of the breast or known or suspected carcinoma of the prostate; women who are pregnant (testosterone may cause fetal harm); patients with known hypersensitivity to KYZATREX or any of its ingredients; and men with hypogonadal conditions that are not associated with structural or genetic etiologies, as KYZATREX has not been established for these conditions and there is a risk of increased BP that can increase the risk of MACE.

Please refer to the Important Safety Information below for additional warnings and precautions, drug interactions, use in special populations, and common side effects.

What is the recommended dosing for KYZATREX?

The recommended starting dose is (2) 100mg soft gels twice daily – once in the morning and once in the evening (400 mg total per day). Dosing may be adjusted depending on how your patient responds to KYZATREX. The minimum recommended dose is 100 mg once daily in the morning. The maximum recommended dose is 400 mg twice daily. For total daily doses greater than 100 mg, administer the same dose in the morning and evening.

Check serum testosterone concentration at least 7 days after starting treatment or after dosage adjustment, 3 to 5 hours after the morning dose. Periodically monitor serum testosterone concentration.

How do I prescribe KYZATREX?

There are three ways to prescribe KYZATREX. You can send the Rx to select specialty mail-order pharmacies, you can utilize UroGPO to offer in-office dispensing, or you can opt for the bill clinic model.

How can I learn more about KYZATREX?

Our sales representatives are on standby to answer any additional questions you may have and assist you in integrating KYZATREX into your practice.


  1. KYZATREX® [prescribing information]. Raleigh, NC: Marius Pharmaceuticals; 2023.

Important Safety Information for KYZATREX (testosterone undecanoate)
KYZATREX can increase blood pressure, which can increase the risk of having a heart attack or stroke and can increase risk of death due to a heart attack or stroke.
Your risk may be greater if you have already had a heart attack or stroke or if you have other risk factors for heart attack or stroke.


Leaving the Consumer Site

You are now entering a site that is for US healthcare professionals only. Products or treatments described on this site are available in the United States but may not be available in all other countries. If you are interested in becoming a KYZATREX prescriber, please enter your information below.

You can also continue to the Prescriber site now to learn more about KYZATREX and becoming a prescriber.