Total testosterone

Method

Serum or plasma total testosterone concentration by liquid chromatography with tandem mass-spectrometry or by immunoassay, in a sample drawn at a stated time of day.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

Time of draw is not optional context here: the diurnal fall between morning and afternoon exceeds most reported treatment effects, so an edge without a stated draw time is describing a range rather than a value. Total rather than free or bioavailable — those are separate quantities derived through binding assumptions that differ between laboratories.

Findings

1 finding from 1 compound, strongest first.

• resveratrol — decreases

  AWell establishedGrade A, Well established. Replicated human trial evidence, consistent direction.Finding

  “The pooled effect estimate indicated that resveratrol significantly reduced the level of testosterone, compared with the placebo (SMD = -0.40; 95% CI [-0.71, -0.10], P = 0.009).”

  Study

  meta-analysis

  Participants

  169

  Dose

  800, 1000 or 1500 mg/day oral resveratrol

  Population

  Women with polycystic ovary syndrome; 3 of 4 pooled RCTs, resveratrol vs placebo

  Effect -0.4 standardised mean difference, 95% CI -0.71 to -0.1

  Efficacy of resveratrol in women with polycystic ovary syndrome: a systematic review and meta-analysis of randomized clinical trials.2023PMID:37333786