Summary of findings 1. Summary of findings.

Population: Male participants Intervention: Atorvastatin   Comparison: Placebo or no treatment
Outcomes	Number of participants (RCTs)	Mean difference of atorvastatin compared to placebo (95% CI)	The certainty of evidence (GRADE)
Total testosterone	140 (2)	‐0.20 nmol/L (‐0.77 to 0.37)	Very low 1, 2, 3
Acronyms and grades
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RCT: randomized controlled trial
GRADE Working Group grades of evidence High certainty: We are very confident that the true effect lies close to that of the estimate of the effect Moderate certainty: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different Low certainty: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect Very low certainty: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect

1 Unclear risk of selection bias.

2 95% confidence interval around the best effect estimate includes both a reduction and an increase in total testosterone.

3 Evidence was derived from only two studies, which had several limitations.