Testosterone Undecanoate (oral)
Hormone Restoration
In plain English
This is a form of testosterone that can be swallowed as a capsule rather than injected or applied to the skin. It is used to raise testosterone in men whose bodies do not make enough. It is usually taken twice a day with food. Because blood pressure can rise on this medicine, a clinician monitors it along with testosterone levels.
The science
Testosterone undecanoate is a long-chain fatty-acid ester of testosterone. In the oral formulation it is absorbed largely via the intestinal lymphatics, bypassing first-pass hepatic metabolism, which avoids the liver toxicity historically associated with 17-alpha-alkylated oral androgens. The pivotal phase 3 trial (Swerdloff et al., 2020) restored average testosterone into the eugonadal range in ~87% of hypogonadal men, with a profile consistent with other testosterone therapies except for more mild GI effects and a mean systolic blood-pressure increase of ~3-5 mmHg. FDA-approved branded oral TU products exist for men with classic (not age-related) hypogonadism; VPI's compounded testosterone undecanoate capsules are not FDA-approved formulations. Contraindicated in known/suspected breast or prostate cancer; monitor blood pressure, hematocrit, lipids, and PSA. Fertility suppression applies as with other exogenous androgens.