Oral testosterone: how the newer capsules work

Why oral testosterone used to be a problem

Plain testosterone swallowed as a pill is broken down by the liver before much reaches the bloodstream. To get around this, older oral products were chemically modified, most commonly as 17-alpha-alkylated androgens such as methyltestosterone. Those versions survived the liver but were linked to liver injury, so oral therapy fell out of favor in the U.S.

Testosterone undecanoate takes a different route. Attached to a long fatty chain, it is absorbed from the gut into the lymphatic system with dietary fat and enters the bloodstream largely bypassing the liver's first pass. The current Kyzatrex label states it is not a 17-alpha-alkyl androgen and is not known to cause liver adverse effects.

Who it is approved for

FDA-approved oral testosterone undecanoate is indicated for adult men with conditions that cause a deficiency or absence of their own testosterone, such as testicular failure or pituitary problems. Its label states that safety and effectiveness in men with age-related hypogonadism have not been established.

In practice, that means diagnosis follows the same rules as for any testosterone therapy: symptoms plus consistently low morning testosterone on at least two occasions, along with tests such as LH to understand the cause.

The food requirement

Because absorption depends on dietary fat, oral testosterone undecanoate is taken with meals, typically twice a day. The label's starting dose is taken with food, and skipping meals or taking it on an empty stomach substantially reduces how much you absorb.

For men who eat regular breakfasts and dinners, this is easy to build into a routine. For those who skip meals, fast for long periods or travel unpredictably, levels may be less consistent.

Blood pressure: what changed and what did not

Oral testosterone undecanoate can raise blood pressure, which can increase cardiovascular risk. When these products first launched, their labels carried a boxed warning about this. According to the current Kyzatrex label on DailyMed, that boxed warning was removed in July 2025.

The underlying warning remains. The label advises periodic blood pressure monitoring, especially in men with hypertension, and says the product is not recommended for people with uncontrolled hypertension. FDA's 2025 class-wide update also added a blood pressure warning to all testosterone products, whatever the route.

What is monitored

If hematocrit rises too high, the label says to stop treatment until it falls, and to discontinue permanently if it rises again after restarting.

• Testosterone levels, drawn a few hours after the morning dose, about a week after starting or changing the dose
• Blood pressure, periodically and more closely if you have hypertension
• Hematocrit before starting and roughly every three months during treatment, per the label
• PSA and prostate health before and during treatment
• Lipids, liver tests if symptoms suggest a problem, and how your symptoms respond

Side effects and who should not use it

Possible side effects include higher blood pressure, a rise in red blood cells, acne, headache, fluid retention, breast tenderness and changes in lipids. Like all testosterone therapy, it suppresses sperm production, so it is not suitable for men trying to conceive.

It is not used in men with breast or prostate cancer, in women or in anyone who is pregnant. Men with uncontrolled blood pressure, significant heart disease, untreated severe sleep apnea or a high hematocrit need careful evaluation first.

Practical tips if you are prescribed it

Link your doses to two regular meals so they become automatic, and keep the timing consistent. If you miss a meal, ask your clinician how to handle that dose rather than doubling up later. Bring a home blood pressure log to follow-up visits; readings taken at home over several days give a clearer picture than a single clinic measurement.

Tell every clinician you see that you take testosterone, including before blood tests, and let your prescriber know about any new medications, especially those that affect blood pressure.

Is it right for you?

Oral testosterone undecanoate suits men who strongly prefer to avoid needles, have well-controlled blood pressure and eat regular meals. Injections may suit men who prefer less frequent dosing or lower cost. Your clinician will help you weigh these factors.

HealifyMD's testosterone replacement therapy is $249 for the first month, then $149/month. The first month includes the lab panel, and your price is confirmed at the eligibility review.