There have been links between coffee and testosterone levels for quite some time. Though the studies have been somewhat mixed. Some studies have suggested that caffeine can in fact raise testosterone levels, whilst a few have shown that it has no effect, or that the raise in cortisol levels as a result of drinking coffee results in their ultimately being no difference in free testosterone levels.
That said, let’s get into a few of the most commonly cited studies around caffeine and testosterone levels.
Scientific Research on Caffeine and Testosterone
The International Journal of Sport Nutrition
The most often referenced study when it comes to testosterone and cortisol levels involved 24 professional rugby platers who ingested varying amounts of caffeine (0, 200, 400, and 800 mg) before weight training. The research found that caffeine resulted in an increase in testosterone levels and it did go up based on the amount taken. With 800mg resulting in the highest difference. Although it is worth noting that cortisol also spiked and cortisol decreases testosterone over time, suggesting that the caffeine spike would be short lived. [1]
Nutrition Journal
A much larger study looked at the relationship of caffeine and testosterone levels in a cross-sectional sample of 372 adult men. The researchers found a significant inverse association between caffeine and testosterone. This suggested that higher caffeine consumption did in fact have an association with lower testosterone levels. However, this study did not establish causality meaning that it could simply be other side effects of higher caffeine intake, for example, poor sleep can cause lower testosterone. Or due to the fact that caffeine may reduce the absorption of zinc which is essential to testosterone production and deficiencies have been shown to cause low test, there could be a culprit here. As a result there are several factors that could be mitigated in further tests.
Clinical Trials
There have also been some clinical trials, and they’ve been a mixed bag as well. However, in one notable one it was observed that coffee can significantly lower the production of sex hormone-binding globulin and estrogen concentration in men and lowered testosterone in women. Meaning there would actually be more free testosterone for men in this case. Meaning at this point we have a study to show pretty much every effect caffeine could have on testosterone. However, more research is needed to determine the exact response of estrogen when it comes in contact with caffeine. [3] It's also worth noting that the effects tailed off after 8 weeks and it was a relatively small study.
What does this mean?
Well it likely means that as long as the rest of your nutrition is on point, then caffeine probably isn’t going to hurt, but if it’s effecting your sleep or you’re consuming so much coffee it can deplete essential vitamins for testosterone production, then it’s going to do harm. As for the small trials with effects on SHBG and estrogen, it would need to be replicated with larger samples.
Caffeine's Impact on Other Hormones
Caffeine not only affects testosterone but also interacts with other hormones in the body. Cortisol, also known as the stress hormone, is influenced by caffeine intake. While caffeine can increase testosterone levels, it is essential to maintain a balance, as excessively high cortisol levels may hinder testosterone production. Caffeine also stimulates the release of adrenaline, enhancing energy levels and preparing the body for action. Serotonin and dopamine, neurotransmitters responsible for mood elevation, are influenced by caffeine intake, promoting a sense of well-being. However, excessive coffee consumption can lead to addiction and potentially impact mental health.
Safe Amount of Caffeine
Again there’s a bit of mixed research on this, but The European Food Safety Authority suggests that consuming up to 400 mg of caffeine per day can be considered safe for healthy adults.
Conclusion: Does Caffeine Raise Testosterone?
Maybe, but probably not significantly, at least no by so much that it would compare to other testosterone boosting compounds. However, it also isn’t likely to do any real harm as long as it’s not disrupting sleep and you’re not drinking excessive amounts of coffee.
References
1 - https://pubmed.ncbi.nlm.nih.gov/18458357/
2 - https://nutritionj.biomedcentral.com/articles/10.1186/s12937-022-00783-z
3 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3502342/
