Testosterone Undecanoate for Long-Acting TRT — Anabolic Steroids
Ultra-long-acting testosterone ester available in oral and injectable forms with 20-33 day half-life.
Overview
Testosterone Undecanoate is a long-chain ester providing the longest-acting injectable testosterone formulation available. The injectable form (Aveed/Nebido) has a half-life of 20-33 days, requiring injections only every 10-14 weeks after initial loading. The oral form (Jatenzo/Kyzatrex/Tlando, FDA-approved 2019-2023) bypasses first-pass liver metabolism via lymphatic absorption, offering a needle-free TRT option. The injectable requires administration under the FDA REMS program due to rare risk of pulmonary oil microembolism (POME). This formulation is ideal for patients who prefer infrequent injections or oral convenience, though the extended half-life means slower dose adjustments compared to shorter esters.
Indications
- Primary and secondary hypogonadism - long-acting option
- Patients preferring infrequent injections (every 10-14 weeks)
- Oral TRT for needle-averse patients
- Stable long-term testosterone replacement
- Hypogonadism management in compliant patients
- Androgen deficiency with preference for minimal clinic visits
Mechanism of Action
Testosterone deficiency in patients preferring infrequent dosing or oral convenience
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Testosterone Undecanoate (Injectable) | 750 mg | Every 10-14 weeks | Initial: 750mg, repeat at 4 weeks, then every 10 weeks thereafter |
| Testosterone Undecanoate (Oral) | 158-396 mg | Twice daily with meals | Oral capsules taken twice daily with food; dose adjusted by testosterone levels |
| Testosterone Undecanoate (Oral) | 225 mg | Twice daily with meals | Oral capsule, taken twice daily with food |
Evidence Grade
GRADE A
Safety & Contraindications
- Injectable: FDA REMS program required due to POME risk
- Post-injection observation period of 30 minutes required (injectable)
- Pulmonary oil microembolism (POME) - rare but serious risk with injectable
- Oral form: must be taken with food (fat-containing meal) for absorption
- Oral form: potential blood pressure elevation - monitor
- Monitor hematocrit for polycythemia
- Long half-life means slower dose adjustment capability
- Contraindicated in prostate or breast cancer
- Monitor PSA in men over 40
- Oral forms may have variable absorption depending on dietary fat intake