Testosterone Undecanoate Research Guide

Full name: Testosterone Undecanoate (Ultra-Long Ester)

An ultra-long-acting testosterone ester available as a deep intramuscular injection (e.g. Nebido/Aveed) or oral capsule (Jatenzo). Used medically for TRT with very infrequent dosing. Educational reference only.

How Testosterone Undecanoate Works

The large undecanoate ester dramatically slows release, giving weeks-long duration from a single injection. Oral undecanoate is absorbed via the lymphatic system, partly bypassing first-pass liver metabolism.

Dosing Protocol

• Typical dose: Injection every ~10-14 weeks (medical); oral 2x daily with food
• Frequency: Infrequent (injection) or twice daily (oral)
• Duration: Ongoing (medical)
• Route: Deep intramuscular injection or oral

Reported Benefits

• Very infrequent injections (convenience)
• Stable long-term testosterone (medical)
• Oral option avoids most liver toxicity
• Restores testosterone in deficiency

Potential Side Effects

• Testosterone suppression
• Elevated hematocrit
• Estrogenic effects
• Rare pulmonary oil microembolism (injection)
• Blood pressure elevation (oral)

Research Citations

1. Long-acting testosterone undecanoate (2019) - Provided stable physiological testosterone with dosing every ~10-14 weeks in hypogonadal men.

Related Anabolic Steroids Compounds

• Testosterone Enanthate - Full Profile
• Testosterone Propionate - Full Profile
• Testosterone Suspension - Full Profile
• Sustanon 250 - Full Profile
• Nandrolone Decanoate - Full Profile
• Nandrolone Phenylpropionate - Full Profile

View full Testosterone Undecanoate profile with 3D molecule viewer →