Effects of different doses of testosterone on gonadotropins, 25-hydroxyvitamin D3, and blood lipids in healthy men.
Level 3 - non-randomized controlled study
Prospective single-arm within-subject interventional study without reported randomization
PubMed 25525405 · doi:10.2147/SAR.S71285
What was done
Twenty-five healthy male volunteers aged 27–43 years were administered single intramuscular doses of testosterone enanthate at 125 mg, 250 mg, and 500 mg, each separated by a 6- to 8-week washout period. Researchers measured serum testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), 25-hydroxyvitamin D3, and blood lipids (total cholesterol, LDL, HDL, ApoA1, ApoB, triglycerides, lipoprotein(a)) before dosing as well as 4 and 14 days after injection. Urinary testosterone/epitestosterone ratios were evaluated before each dose.
What was found
All tested doses suppressed serum LH and FSH concentrations, with LH remaining suppressed 6 weeks following the 500 mg dose. The 250 mg and 500 mg doses decreased plasma ApoA1 and HDL concentrations, whereas the 125 mg dose produced no effect on the lipid profile. Single doses produced a dose-dependent increase in serum testosterone. No changes were observed in 25-hydroxyvitamin D3 levels relative to baseline. The abstract reports no numerical values, variances, or p-values.
Why it matters
The findings demonstrate that even single supraphysiological doses of testosterone can lead to prolonged suppression of the hypothalamic-pituitary-gonadal axis and acutely lower cardioprotective HDL and ApoA1 levels.
Limits
The abstract provides no raw numbers, effect sizes, or confidence intervals. The study was conducted in a small cohort (n = 25) of healthy men and assessed only single doses rather than chronic administration patterns typical of steroid abuse. It is not stated whether dose sequencing was randomized.
Cited by
- supports Suppression of gonadotropins occurs within days of starting exogenous testosterone administration.