PMID-15713727 – Low-Dose HCG Maintains Intratesticular Testosterone
Coviello AD, Matsumoto AM, Bremner WJ, Herbst KL, Amory JK, Anawalt BD, Sutton PR, Wright WW, Brown TR, Yan X, Zirkin BR, Jarow JP. Low-dose human chorionic gonadotropin maintains intratesticular testosterone in normal men with testosterone-induced gonadotropin suppression. J Clin Endocrinol Metab. 2005;90(5):2595-2602.
Quick Reference
| Property | Value |
|---|---|
| PMID | 15713727 |
| DOI | 10.1210/jc.2004-0802 |
| Year | 2005 |
| Journal | Journal of Clinical Endocrinology & Metabolism |
| Study Type | RCT |
| Evidence Level | II |
| Sample | 29 healthy men, ages 18-49 |
| Peptide(s) Studied | HCG |
Key Findings
- 29 men randomized to receive 200 mg testosterone enanthate weekly + HCG at 125, 250, or 500 IU every other day for 3 weeks
- Post-treatment intratesticular testosterone (ITT) was 25% less than baseline in the 125 IU group
- ITT was 7% less than baseline in the 250 IU group (near-complete preservation)
- ITT was 26% greater than baseline in the 500 IU group
- Demonstrates that relatively low-dose HCG can maintain ITT even during exogenous testosterone administration
- Serum testosterone levels were supraphysiological in all groups due to exogenous T
Study Design
Randomized, controlled trial. 29 normal men received weekly IM testosterone enanthate 200 mg to suppress endogenous gonadotropins, plus HCG at three dose levels (125, 250, or 500 IU every other day) for 3 weeks. ITT was measured by fine-needle aspiration of testicular fluid.
Limitations
- Short duration (3 weeks)
- Small sample size per group (~10 each)
- Normal healthy volunteers rather than hypogonadal TRT patients
- ITT measurement via fine-needle aspiration is invasive and has variability
- Spermatogenesis outcomes not assessed
Clinical Relevance
Landmark study establishing the dose-response relationship for HCG co-administration during TRT. The finding that 250 IU EOD maintains ~93% of baseline ITT provides the foundation for the widely-used clinical practice of adding low-dose HCG to TRT regimens to preserve testicular function and fertility. This is the most commonly cited study supporting HCG co-administration with TRT.
Related
#research #RCT #HCG #evidence-level-II