From the Guidelines
Kyzatrex is not well absorbed as a testosterone supplement. The absorption of Kyzatrex, an oral testosterone undecanoate capsule, is limited by first-pass metabolism in the liver, which significantly reduces the amount of active testosterone reaching the bloodstream 1. This is a common challenge with oral testosterone preparations. According to the FDA, Kyzatrex is contraindicated in men with hypogonadal conditions, such as age-related hypogonadism, that are not associated with structural or genetic etiologies, citing demonstrated increases in blood pressure and lack of established efficacy 1.
Some key points to consider when evaluating the absorption of Kyzatrex include:
- Variable absorption rates in clinical studies 1
- Requirement for administration with food, particularly meals containing fat, to enhance absorption
- Need for consistent dosing and regular monitoring of testosterone levels to ensure therapeutic effectiveness
- Comparison to other testosterone replacement options, such as injections, transdermal gels, or patches, which typically provide more reliable absorption and stable testosterone levels 1
It is essential to consult with a healthcare provider to recommend the most appropriate formulation based on individual needs, lifestyle factors, and medical history. The healthcare provider can help determine the best course of treatment and ensure that the patient receives the most effective and safe testosterone replacement therapy.
From the FDA Drug Label
Testosterone Undecanoate Capsules was taken orally at a starting dose of 200 mg twice per day with meals in a multicenter, open-label trial in hypogonadal males The average daily NaF/EDTA plasma testosterone concentration was 393.3 (±113. 6) ng/dL after 90 days of treatment When Testosterone Undecanoate [Capsules] was given with breakfast containing 16%, 33%, and 45% fat, the exposure (AUC 0-24 hr) of testosterone was increased by 37%, 87%, and 94%, respectively, compared to when given under fasted conditions.
The question asks about kyzatrex, but the provided drug label is for testosterone undecanoate. Since there is no information about kyzatrex in the provided drug label, The FDA drug label does not answer the question.
From the Research
Testosterone Absorption
- Kyzatrex is a form of oral testosterone undecanoate, which is a long-acting ester formulation of testosterone 2.
- The pharmacokinetics of testosterone undecanoate products, including Kyzatrex, provide a convenient option for many patients, which may increase compliance with testosterone therapy (TT) 2.
Comparison with Other Testosterone Formulations
- Testosterone undecanoate (TU) is compared to testosterone enanthate (TE) in several studies, showing that both formulations are effective and safe for treating hypogonadism 3, 4.
- TU and TE produce similar increases in hemoglobin and hematocrit, and both treatments lead to a decline in total serum cholesterol, LDL cholesterol, and triglycerides 3, 4.
Pharmacokinetics of Testosterone Undecanoate
- A pharmacokinetic study of injectable testosterone undecanoate in hypogonadal men shows that mean serum testosterone levels increase significantly after injection and decrease progressively over time 5.
- The terminal elimination half-life of testosterone undecanoate is around 18-24 days, and the mean residence time is around 21-23 days 5.
Efficacy and Safety
- Studies show that testosterone undecanoate and testosterone enanthate injections are both effective and safe in transmen over 5 years of administration 4.
- The administration of either TU or TE for 5 years in young transmen is associated with an increase in hemoglobin and hematocrit, and a slight reduction in high-density lipoprotein cholesterol 4.