Coffee and Testosterone Levels
The evidence does not support a consistent or clinically meaningful relationship between coffee consumption and testosterone levels in men.
Key Findings from Clinical Evidence
The highest quality randomized controlled trial found no significant effect of coffee on testosterone. An 8-week RCT in 42 healthy adults showed no significant differences in testosterone levels between caffeinated coffee, decaffeinated coffee, or water control groups at the primary endpoint 1. While some transient changes were observed at 4 weeks (caffeinated coffee increased total testosterone in men, while both caffeinated and decaffeinated coffee decreased testosterone in women), these effects were not sustained and the study authors emphasized caution due to small sample size 1.
Cross-Sectional Population Studies Show Conflicting Results
Large population-based studies demonstrate inconsistent associations:
A 2022 NHANES analysis of 372 men found an inverse association between caffeine intake and testosterone levels, with 6 caffeine metabolites showing negative correlations 2. However, this cross-sectional design cannot establish causation and may reflect confounding factors.
Conversely, a larger 2019 NHANES study of 2,581 men found no linear relationship between caffeine intake and testosterone, though a non-linear association was detected in certain subgroups (Mexican-American and Non-Hispanic White men, and those with lower adiposity measures) 3. The clinical significance of this non-linear pattern remains unclear.
Exercise Context: Acute Effects Differ from Chronic Consumption
In the specific context of resistance exercise, caffeine shows dose-dependent acute hormonal effects. A study of 24 professional rugby players found that 800 mg caffeine increased testosterone by 21% during exercise but also raised cortisol by 52%, resulting in a net decline in the testosterone:cortisol ratio 4. A 2024 study in football players similarly showed that caffeinated coffee increased anaerobic power and was associated with higher testosterone levels compared to placebo 5.
Clinical Bottom Line
For routine clinical purposes, coffee consumption does not require consideration when evaluating testosterone status. The evidence is too inconsistent and the effect sizes too small or transient to warrant clinical action. The RCT data—the highest quality evidence for causation—shows no sustained effect 1. Cross-sectional associations may reflect reverse causation, confounding, or statistical artifacts rather than true biological effects 2, 3.
Important caveats:
- Acute exercise studies show transient hormonal changes with high-dose caffeine (≥800 mg), but these do not translate to chronic alterations in baseline testosterone 4
- Coffee should still be avoided before cardiovascular autonomic testing and exercise stress testing due to effects on heart rate and autonomic function, but this relates to test accuracy rather than testosterone measurement 6
- The non-linear associations observed in some populations warrant further investigation but currently lack clinical applicability 3