Is there any meaningful connection between drinking coffee and higher testosterone levels?
We know caffeine — the main ingredient responsible for coffee’s alertness-enhancing reputation — reliably boosts physical performance.
But what about the most important male hormone in our bodies?
Will caffeine increase testosterone, and if so, is the increase meaningfully sustained over a long period of time?
And if there’s any decrease in testosterone levels because of caffeine, is it something we should cut out of our lives for good?
This article is written to give you the once-and-for-all answer.
What Does Science Say About Coffee And Testosterone Levels?
Fortunately for us, there’s enough data in the medical literature to give us a solid answer.
At the very least we can see if there’s any reason to believe there’s a strong connection between caffeine intake and a man’s testosterone levels.
Caffeine Increasing Testosterone Levels
One of the most quoted studies purporting a link between caffeine and testosterone was published in 2012 in Nutrition Journal.
It was an 8-week randomized trial where healthy 14 men and 28 women who (a) consumed at least 2 cups of coffee per day [~200 mg caffeine], (b) did not smoke, and (c) were overweight.
After abstaining from any caffeine consumption for two weeks prior to the study, one group of subjects consumed five 6-ounce cups of coffee a day (~340 mg caffeine), another group consumed decaffeinated coffee, and the third group drank water.
Here’s what researchers found:
“No significant differences were found between treatment groups for any of the studied outcomes at week 8. At 4 weeks, decaffeinated coffee was associated with a borderline significant increase in SHBG in women, but not in men. At week 4, we also observed several differences in hormone concentrations between the treatment groups.
Among men, consumption of caffeinated coffee increased total testosterone and decreased total and free estradiol. Among women, decaffeinated coffee decreased total and free testosterone and caffeinated coffee decreased total testosterone.”
But as other people have pointed out, this study wasn’t perfect and each group size was rather small.
The good news is that we have a VERY large 2019 observational study of nearly ~15,000 women and ~7,400 men working in American healthcare who were free of cancer, heart disease, or diabetes.
After adjusting for factors such as lifestyle habits and demographics, a stark difference was noted between people who drank coffee and people who didn’t:
“Compared with nondrinkers, participants who drank ≥4 cups of total coffee/d had lower concentrations of C-peptide (−8.7%), IGFBP-3 (−2.2%), estrone (−6.4%), total estradiol (−5.7%), free estradiol (−8.1%), leptin (−6.4%), CRP (−16.6%), IL-6 (−8.1%), and sTNFR-2 (−5.8%) and higher concentrations of SHBG (5.0%), total testosterone (7.3% in women and 5.3% in men), total adiponectin (9.3%), and HMW adiponectin (17.2%). The results were largely similar for caffeinated and decaffeinated coffee.”
The remaining studies that show a positive connection between caffeine and testosterone do so in relation to what happens after resistance exercise.
Specifically, they examine if the testosterone boost already observed post-workout is heightened further by caffeine.
Let’s see what they found…
2008 – “Dose effect of caffeine on testosterone and cortisol responses to resistance exercise”
24 pro rugby players took varying doses of caffeine 60 minutes before training (0, 200, 400, or 800 mg caffeine).
Testosterone and other biomarkers were measured immediately after taking caffeine, at various points during training, and various points after training.
“Testosterone concentration showed a small increase of 15% (90% confidence limits, +/- 19%) during exercise. Caffeine raised this concentration in a dose-dependent manner by a further small 21% (+/- 24%) at the highest dose. The 800-mg dose also produced a moderate 52% (+/- 44%) increase in cortisol. The effect of caffeine on the testosterone:cortisol ratio was a small decline (14%; +/- 21%).”
9 well-trained male cyclists in their mid-20s who habitually consumed less than 300 mg of caffeine per day were recruited.
They abstained from all sources of caffeine sources before the experiment, where they did four sets of five 30-second sprints.
This experiment was completed three more times for a total of four sessions.
The cyclists took either a placebo or 240 mg of caffeine (via chewing gum) on the second set of each experimental session.
“Salivary testosterone increased rapidly from rest (~53%) and prior to treatments in all trials. Following caffeine treatment, testosterone increased by a further 12 ± 14% (ES 0.50; ± 0.56) relative to the placebo condition.
…following the caffeine treatment cortisol was reduced by 21 ± 31% (ES -0.30; ± 0.34) relative to placebo. The acute ingestion of caffeine via chewing gum attenuated fatigue during repeated, high-intensity sprint exercise in competitive cyclists. Furthermore, the delayed fatigue was associated with substantially elevated testosterone concentrations and decreased cortisol in the caffeine trials.”
2015 – “Dose effects of caffeine ingestion on acute hormonal responses to resistance exercise”
Twelve university-aged resistance-trained males took either a high dose (6 mg/kg), medium dose (4 mg/kg), low dose (2 mg/kg), or no dose of caffeine one hour before doing 2 exercises for 3 sets of 10 reps at 75% of their 1-rep max.
Blood samples were taken at numerous points before, during, and after resistance training.
Every experiment involving a different dose of caffeine was separated by a total of 7 days to allow for a “wash-out”.
“The concentrations of testosterone and cortisol [immediately after, 15 minutes after, and 30 minutes after exercise] at [the high dose] were significantly increased. However, the responses of insulin (P0 and P15) at [the high dose] and [the medium dose] were significantly decreased.”
2019 – “Caffeine added to coffee does not alter the acute testosterone response to exercise in resistance trained males”
Males with experience in strength training performed an exercise session consisting of 21 minutes of high-intensity interval training, followed by seven exercises done for 3 sets of 10 reps at 65% of their 1-rep max with 60-second rest periods.
They got 6 mg/kg body weight of caffeine, but were supplemented with either decaffeinated coffee or anhydrous caffeine prior to exercising.
“[Testosterone] was elevated immediately and 30-minutes post-exercise by 20.5% and 14.3% respectively (P<0.05). There was no main effect for treatment and no exercise x treatment interaction. There were no differences in repetitions to fatigue or soreness between treatments (P>0.05). No relationships were observed between [testosterone] and any proxy of recovery.”
In other words, adding MORE caffeine to coffee did not necessarily make things better.
Caffeine Having ZERO Effect On Testosterone Levels
However, not every study found a link between ingesting more caffeine and boosting your testosterone levels.
There’s enough evidence to also suggest it doesn’t make a meaningful short-term or long-term difference.
2018 – “Consumption of caffeinated beverages and serum concentrations of sex steroid hormones in US men”
This observational data involved 1,410 men in their 20s who participated in the Third National Health and Nutrition Examination Survey that took place between 1988 and 1991.
Caffeine intake was estimated on the basis of how frequently coffee, tea, soft drinks, and other caffeine-containing beverages were consumed.
“Coffee consumption was positively associated with SHBG [sex hormone binding gloublin] concentration (p = 0.045) taking lifestyle factors into account, but mutually adjusting for testosterone and estradiol attenuated the association; no association with SHBG was observed for soft drink consumption or caffeine intake.
No associations between caffeinated beverage consumption and androgen or estrogen concentrations were observed.“
2018 – “Caffeine intake is not associated with serum testosterone levels in adult men”
Here is another observational study involving 2,581 men in their 20s who participated in the CDC’s cross-sectional National Health and Nutrition Examination Survey (NHANES) between 1999-2004 and 2011-2012.
Dietary recalls of food items and beverages containing caffeine were used to estimate daily caffeine intake, and testosterone levels were measured via immunoassay.
“We identified no linear relationship between caffeine intake and testosterone levels in the total population, but there was a non-linear association (pnonlinearity < .01). Similarly, stratified analysis showed nonlinear associations among Mexican-American and Non-Hispanic White men (pnonlinearity ≤ .03 both) and only among men with waist circumference <102 cm and body mass index <25 kg/m2 (pnonlinearity < .01, both).”
(For those of you wondering what “non-linear” means, it could mean there is no relationship, the relationship is unpredictable, or it’s not as simple as “doing more of x = y occurs more/less often)
So clearly we have opposing views regarding caffeine’s effect on testosterone levels, or lack thereof.
Yet there are numerous limitations to all the studies mentioned so far, some occurring more often than others:
- Very small sample sizes
- Highly specific criteria for test subjects
- Not necessarily accounting for ALL sources of caffeine intake
- Caffeine intake is estimated/measured via self-reporting, if at all
- Studies are conducted over a short period of time
- Inadequate time allocated for caffeine withdrawal to dissipate completely
But what about the possible downsides?
A Possible Mechanism Explaining How Caffeine Affects Testosterone Levels
For those of you who don’t know, the stress hormone cortisol is largely catabolic in nature (i.e. it breaks down lean body mass when produced in excess).
And anybody who knows their biochemistry is familiar with how high cortisol production can lower testosterone levels.
So it would logically follow that we would see caffeine consumption — which increases cortisol production — lead to a reduction in testosterone levels.
By extension, one could argue that exercise itself produces cortisol and therefore negatively affects testosterone.
But this doesn’t hold up in real life… otherwise we’d see gym rats suffer from sub-optimal testosterone levels (which we don’t).
How can this be explained?
Does cortisol’s catabolic effects cancel out testosterone’s anabolic effects?
Do we therefore have a connection between higher caffeine intake and lower testosterone levels?
It’s entirely possible, and the mechanism isn’t entirely out of the realm of possibility:
“Bambino and Hsueh (1981) showed a direct inhibitory effect of high doses of glucocorticoids upon testicular Leydig cell function in rats, which resulted in a decrease in the production of testosterone.
Cumming et al. (1983) found a similar relationship in humans, using pharmacological doses of cortisol to induce a decrease in testosterone production. These latter researchers speculated cortisol disrupted the testicular testosterone production process”
And back in 1997, an endocrinologist proposed a mechanism for how higher stress/cortisol levels could lower testosterone production:
“Hardy found receptors in adult Leydig cells that mediate the action of glucocorticoid hormone [cortisol]. In small amounts, glucocorticoid helps cells grow and thrive, but in the large amounts produced during times of stress, it disrupts normal body processes.
Too much glucocorticoid overwhelms the Leydig cell defense mechanism, which is controlled by an enzyme called, for short, 11ßHSD-1. The cell produces only enough 11ßHSD-1 to cope with normal amounts of glucocorticoid.
The surfeit of hormone overwhelms the capacity of 11ßHSD-1 to neutralize it, shortcircuiting testosterone production. Without testosterone, other sperm-making cells do not begin to manufacture sperm”
However, my final answer is a big fat NO … or the decrease is so insignificant to the point where it’s a waste of time to worry about it.
First, recall that the studies involving caffeine ingestion before exercise saw increases in testosterone AND cortisol production.
Why would see levels of both hormones going up, given that the latter should inhibit production of the former?
Furthermore, in the 2008 study quoted earlier, we only saw significant boosts in cortisol when extremely high quantities of caffeine (800 mg) were consumed.
Moreover, just like the testosterone increases, the cortisol increases are short-lived and do not stay elevated for extended periods of time.
Second, caffeine is believed to be an aromatase inhibitor in some women.
Some evidence (here and here) suggests this possibility, although it hasn’t been extensively studied in men.
Also, the pivotal 2012 study I quoted earlier found men had higher testosterone levels and lower estrogen levels after consuming caffeinated coffee.
I’m not saying this is a good thing, as I’ve repeatedly stated testosterone MUST convert to estrogen for its positive health benefits to fully manifest.
But it’s something to think about as the body is incredibly complicated in design.
Life is very rarely as simple as “Hormone #1 affects Hormone #2 and absolutely no other downstream consequences take place”.
Third, caffeine indirectly increases testosterone production through the preservation of cyclic adenosine monophosphate (cAMP).
Caffeine is what is known as a “non-selective phosphodiesterase (PDE) inhibitor”, and it can specifically inhibit PDE-1, PDE-4, and PDE-5.
Inhibiting these enzymes, specifically PDE-4, prevents the degradation of cAMP, an intracellular second messenger that allows hormones to exert their effects when they cannot directly cross the cell membrane (thus triggering a cascade of reactions).
And thanks to the accumulation of cAMP, it’s not unreasonable to see an increase in testosterone levels:
“cAMP stimulates the mobilization and transport of cholesterol to and into the mitochondria in part by activating PKA and MAPK signaling. At the same time, AA can be converted into prostaglandin by Cox2 to negatively regulate the transport of cholesterol across the mitochondrial membranes. At the inner mitochondrial membrane, cholesterol is converted to pregnenolone by CYP11A1, and pregnenolone is converted into testosterone by enzymes in the smooth endoplasmic reticulum (HSD3b, CYP17A1 and HSD17b”
Weirdly enough, this same mechanism is likely why many people on therapeutic testosterone (here, here, and here) report reducing or eliminating caffeine altogether due to increased jitters (i.e. the coffee “hits harder” as you’re already amped up from optimized testosterone levels).
I recommend reading this open-source paper if you want to learn more about how caffeine affects testosterone and other vital hormones in both men and women.
Will Pregnant Women Lower Their Sons’ Testosterone Levels If They Drink Coffee?
This is an interesting aside I came about while researching this article.
Although there’s no human data to support this, several rat studies suggest moderate doses of caffeine can interfere with the offspring’s testosterone production, impair gonadal development, compromise the maturation of testis, and the effects may prolong into the second generation of offspring.
However, even excluding the issue of low testosterone, some scientists are changing their mind about how much caffeine is safe for pregnant women to have.
The standard recommendation is no more than 200 mg of caffeine (2 cups of coffee) a day, according to the American College of Obstetricians and Gynecologists.
Icelandic sychology professor Dr. Jack James feels differently, having analyzed 48 observational studies examining pregnancy outcomes linked to caffeine consumption:
“Of 42 separate sets of findings reported in 37 observational studies, 32 indicated significantly increased caffeine-related risk and 10 suggested no or inconclusive associations. Caffeine-related increased risk was reported with moderate to high levels of consistency for all pregnancy outcomes except preterm birth.
Of 11 studies reporting 17 meta-analyses, there was unanimity among 14 analyses in finding maternal caffeine consumption to be associated with increased risk for the four outcome categories of miscarriage, stillbirth, low birth weight and/or small for gestational age, and childhood acute leukaemia”
(There’s some ongoing debate about whether this analysis is legitimate, but I’ll leave that to the epidemiologists)
And in another cohort study, even keeping caffeine consumption below 200 mg still showed an associative link to unusual anthropometric measures in newborn babies (birth weight, limb measurements, etc.).
Not to mention the possibility of “neurodevelopmental complications” in children whose mothers frequently drank coffee while pregnant.
I’m not here to tell childbearing women what they can and can’t do… but they should definitely think twice before chugging down a pot of Joe to make up for a sleepless night.
Caffeine And Testosterone Lab Tests: What You Need To Know
My recommendation is to AVOID consuming any kind of caffeine at least 24 hours before any blood work you do, testosterone or not.
This is not just me — any diagnostics lab will tell you to avoid drinking coffee in advance of the test (among other activities such as drinking alcohol, smoking cigarettes, and eating certain foods).
And even if the lab didn’t have that requirement, you should abstain from caffeine out of an abundance of caution.
You do want the most accurate results possible, right?
But let me be clear about one thing…
Drinking Coffee Will NOT Fix Low Testosterone Levels
The reason I recommend staying away from caffeine is because we do not want short-term, transient testosterone increases compromising the results of lab work.
This is entirely separate from the notion that drinking coffee will naturally lead to meaningful, sustainable testosterone level boosts in the long run.
Much like pointless practices such as sunning your balls or taking “testosterone boosters”, all you’re doing is wasting your time and money.
You won’t get the results you want and you’ll eventually realize you have to correctly use testosterone therapy.
Granted, coffee is extremely cheap and easy to consume once a day.
You’ll get the extra energy boost you want and the feeling of being alive for a couple of hours.
Just don’t expect your cup of Joe to magically fix the world’s leading health crisis in men.
The (Non-Existent) Connection Between Caffeine And Testosterone Levels
Don’t get the wrong idea about coffee — I love having a cup or two at most when I have a hard day of work ahead of me.
I even recommend using it wisely to increase cognition via boosting BDNF production, and it’s part of my advanced fasting strategy in The Metabolic Blowtorch Diet.
Yet I don’t use it for the purpose of increasing your testosterone levels, and neither should you.
The small short bursts of testosterone you may experience will fade away just as quickly and return you to your hormonal baseline.
So why bother chugging an entire pot when all you’ll do is reach a plateau… and experience the worst anxiety of your life?
Use coffee for what it’s designed to do, and not what uneducated fitness experts want you to think it does.
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