Recommended Jatenzo Starting Dose for Patients on 200mg Testosterone Weekly
For a patient currently using 200mg of testosterone per week via injection, start Jatenzo at 237mg (three 79mg capsules) twice daily with food, as this represents the standard initial dose for testosterone replacement therapy. 1
Rationale for Starting Dose
Jatenzo requires standardized initial dosing regardless of prior testosterone formulation, as oral testosterone undecanoate has unique pharmacokinetics that differ substantially from injectable testosterone. 2, 1
The standard starting dose of Jatenzo is 237mg (three 79mg capsules) taken twice daily with meals, which was shown to achieve eugonadal testosterone levels in 84-87% of hypogonadal men in phase III trials. 1
Do not attempt to directly convert from injectable to oral dosing based on milligram equivalency, as oral testosterone undecanoate undergoes extensive first-pass metabolism and has significantly different bioavailability compared to intramuscular testosterone. 2, 3
Critical Administration Requirements
Jatenzo MUST be taken with food - bioavailability is negligible in the fasting state, with testosterone levels increasing more than 10-fold when administered with meals compared to fasting. 3
Each dose should be taken with approximately 20-30 grams of fat to optimize absorption of this lipophilic formulation. 1, 3
Monitoring and Dose Titration
Measure testosterone levels 2-3 months after initiating therapy to assess whether dose adjustment is needed, targeting mid-normal range (450-600 ng/dL). 4, 5
Available dose adjustments include: 158mg (two capsules) BID, 237mg (three capsules) BID, 316mg (four capsules) BID, or 396mg (five capsules) BID based on achieved testosterone levels. 1
The dihydrotestosterone-to-testosterone ratio increases approximately 3-fold with oral testosterone undecanoate compared to injectable formulations, which is a normal pharmacologic effect of this route. 2
Important Safety Considerations
Monitor blood pressure closely - oral testosterone undecanoate was associated with mean systolic blood pressure increases of 3-5 mmHg in clinical trials. 1
Gastrointestinal adverse effects (typically mild) occur more frequently with oral formulations compared to other testosterone preparations. 1
Cardiovascular precautions apply equally - do not initiate within 3-6 months of cardiovascular events, and counsel regarding weight loss if patient is overweight or obese. 4, 5
Monitor hematocrit, though polycythemia occurs less frequently with oral preparations compared to injectable testosterone (which showed 43.8% incidence in some studies). 4