Methyltestosterone vs Testosterone Undecanoate
A side-by-side research comparison of Methyltestosterone and Testosterone Undecanoate across mechanism, dosing, half-life, benefits, side effects and research status.
Comparison table
| Attribute | Methyltestosterone | Testosterone Undecanoate |
|---|---|---|
| Full name | Methyltestosterone (Oral Testosterone) | Testosterone Undecanoate (Ultra-Long Ester) |
| Category | Anabolic Steroids | Anabolic Steroids |
| Status | FDA-approved drug (controlled substance) | FDA-approved drug (controlled substance) |
| Mechanism | A 17-alpha-alkylated testosterone that survives first-pass liver metabolism, allowing oral dosing. It acts on androgen receptors like testosterone and aromatizes to estrogen, but its 17aa structure makes it hepatotoxic. | 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. |
| Molecular weight | 302.5 Da | 456.7 Da |
| Half-life | ~2.5-4 hours | ~20-34 days (injection depot) |
| Bioavailability | Oral (17aa) | Deep IM injection or oral (lymphatic absorption) |
| Typical dose | Medical: ~10-50 mg/day (historical) | Injection every ~10-14 weeks (medical); oral 2x daily with food |
| Frequency | Daily | Infrequent (injection) or twice daily (oral) |
| Route | Oral or buccal tablet | Deep intramuscular injection or oral |
Methyltestosterone reported benefits
- Oral testosterone activity
- Treats androgen deficiency (historical)
- Convenience of oral dosing
Testosterone Undecanoate reported benefits
- Very infrequent injections (convenience)
- Stable long-term testosterone (medical)
- Oral option avoids most liver toxicity
- Restores testosterone in deficiency
Related comparisons
Research and educational reference only. Not medical advice.