Comparison of Outcomes for Hypogonadal Men Treated with Intramuscular Testosterone Cypionate versus Subcutaneous Testosterone Enanthate.
Level 3 - non-randomized controlled study
Non-randomized comparative cohort study evaluating two TRT modalities over 12 weeks
PubMed 34694927 · doi:10.1097/JU.0000000000002301
What was done
Comparative cohort study of 234 hypogonadal men treated with testosterone replacement therapy consisting of either weekly 100 mg intramuscular testosterone cypionate (IM-TC) or weekly 100 mg subcutaneous testosterone enanthate autoinjector (SCTE-AI). Total testosterone (TT), estradiol (E2), hematocrit (HCT), and prostate-specific antigen (PSA) were measured at baseline and at 12 weeks. Linear regression models assessed whether treatment modality was independently associated with 12-week post-treatment biomarker levels after adjusting for covariates.
What was found
Both treatments significantly increased trough TT from baseline at 12 weeks (IM-TC: 313.6 ng/dL to 536.4 ng/dL, p < 0.001; SCTE-AI: 246.6 ng/dL to 552.8 ng/dL, p < 0.001). On multivariable linear regression, TRT modality was not independently associated with post-treatment TT levels (p = 0.057) or PSA elevation (p = 0.965). SCTE-AI was independently associated with lower post-therapy E2 (p < 0.001) and HCT (p < 0.001) compared to IM-TC. Absolute values for post-treatment E2, HCT, and PSA were not reported in the abstract.
Why it matters
Subcutaneous autoinjection of testosterone enanthate achieved therapeutic testosterone levels comparable to intramuscular cypionate while mitigating secondary rises in hematocrit and estradiol over 12 weeks.
Limits
Non-randomized design allows for potential confounding by indication and baseline differences between groups. Follow-up was limited to 12 weeks, precluding assessment of long-term safety, clinical outcomes, or symptom resolution. Absolute post-treatment values and effect sizes for estradiol, hematocrit, and PSA were not reported in the abstract.
Cited by
- supports Subcutaneous injection of testosterone provides slower absorption and more stable serum hormone concentrations compared to intramuscular injection.