The benefits of Theacrine for athletes: the evidence base

Theacrine is often presented as the “next generation of caffeine” for athletes. But there is a substantial difference between marketing promises and scientific data. The editorial team reviewed the published studies in humans, assessed what exactly they measured, and found out how confidently one can speak of a benefit of theacrine for training and competition.

How many studies actually exist

Compared with caffeine, on which thousands of works and several position statements of sports societies have been published, the database on theacrine is very modest. There are only a few dozen clinical studies in humans, and most of them are small, with dozens of participants.

A significant portion of the studies were funded by the company that owns the TeaCrine® trademark, or were conducted using its product. This does not automatically make the results wrong, but it requires caution in interpretation and a need for independent replications.

The studies can be roughly divided into four groups: safety and tolerance, subjective energy and mood, cognitive function, physical performance. The strongest data concern the first group, the weakest — the last.

It is also important that in many works theacrine was studied together with caffeine or as part of multi-component supplements. In such designs it is difficult to separate out the contribution of theacrine itself.

Energy, fatigue and mood

The key work is the study by Taylor et al. (2016), in which healthy participants took 200 or 300 mg of theacrine or placebo daily for eight weeks. The authors assessed safety indicators as well as subjective feelings of energy, fatigue and concentration. No signs of tolerance — that is, a gradual decrease in the effect, as happens with caffeine — were found.

Ziegenfuss et al. (2017) in a two-stage study examined the effect of theacrine on oxygen consumption, hemodynamics and subjective sensations. They reported an improvement in subjective energy and a reduction in fatigue without significant changes in heart rate and blood pressure.

These results are interesting for athletes who need alertness without cardiovascular load. However, subjective scales are sensitive to participants' expectations, and even in double-blind studies some participants can feel the difference between a stimulant and a placebo.

For practice this means: theacrine may affect well-being and the feeling of energy, but this is not yet proof that it improves training performance.

Cognitive function

Kuhman et al. (2015) compared a supplement containing theacrine with caffeine and placebo in young men and women. Cognitive tests and mood were assessed. The results showed certain changes in subjective measures, but the objective cognitive tests did not demonstrate a stable advantage.

In the sports context, the work by Bello et al. (2019) with high-level soccer players is interesting, comparing theacrine, caffeine, their combination and placebo during a simulated match. The authors reported certain improvements in cognitive measures with the combination of substances, but the effects on the different tests were heterogeneous.

From the overall picture it follows that theacrine may contribute to subjective concentration and motivation, especially in combination with caffeine. However, a stable effect on reaction speed, attention or decision-making has not yet been proven.

For sports where the cognitive component is critical — team sports, combat sports, shooting disciplines — larger studies with objective, specific tests are needed.

Strength, power and endurance

It is precisely in this category that athletes expect the greatest effect, and it is precisely here that the evidence base is weakest. Cesareo et al. (2019) assessed the effect of theacrine on muscular strength, endurance and power and did not obtain convincing results in favor of the supplement.

For comparison, caffeine at doses of about 3–6 mg per kilogram of body weight has a well-documented ergogenic effect in endurance, repeated sprints and strength tests. This is reflected in the ISSN position statement (Guest et al., 2021). Theacrine does not have this level of evidence.

The hypothesis that theacrine can “prolong” the action of caffeine during prolonged loads is physiologically plausible, given the pharmacokinetic interaction described by He et al. (2017). But there is currently insufficient direct evidence that this translates into a better time or result.

So it is premature to regard theacrine as an independent ergogenic agent for strength or endurance. If the goal is physical performance, caffeine remains the substance with a far more reliable evidence base.

The quality of the evidence and its limitations

The first limitation is small samples. Studies with a few dozen participants can detect only large effects; moderate changes may be either missed or found by chance.

The second is conflicts of interest. Funding or the provision of a product by the manufacturer does not necessarily distort the results, but independent replications are important for confidence in the conclusions.

The third is the heterogeneity of designs and dosages. Different studies used different doses, combinations and tests, so they are difficult to compare and impossible to combine into a quality meta-analysis.

The fourth is the population. Most participants are young healthy people or amateurs. Data for elite athletes, women in different phases of the cycle, older people or those with comorbidities are limited.

• Best confirmed: the absence of tolerance and the stability of hemodynamics in the 8-week study.
• Moderately confirmed: a subjective increase in energy.
• Weakly confirmed: the effect on cognitive tests and physical results.

Editorial conclusions

The evidence base for theacrine in athletes is still limited. The most convincing data concern the absence of tolerance and a neutral effect on pulse and blood pressure, the weakest — a real improvement in athletic performance.

The subjective feeling of energy and motivation may increase, especially in combination with caffeine, but this is not equivalent to better performance.

For improving results, caffeine remains a tool with a far better evidence base. Theacrine can be considered an additional option for those who tolerate caffeine poorly or want to avoid tolerance, with an understanding of the limitations of the data.

For more detail, read our materials “Theacrine: what it is and how it works,” “How to take Theacrine: dosage, timing, duration” and “Side effects of Theacrine.”

References

1. Taylor L, Mumford P, Roberts M, et al. Safety of TeaCrine®, a non-habituating, naturally-occurring purine alkaloid over eight weeks of continuous use. J Int Soc Sports Nutr. 2016;13:2.
2. Kuhman DJ, Joyner KJ, Bloomer RJ. Cognitive performance and mood following ingestion of a theacrine-containing dietary supplement, caffeine, or placebo by young men and women. Nutrients. 2015;7(11):9618–9632.
3. Ziegenfuss TN, Habowski SM, Sandrock JE, et al. A two-part approach to examine the effects of theacrine (TeaCrine®) supplementation on oxygen consumption, hemodynamic responses, and subjective measures of cognitive and psychometric parameters. J Diet Suppl. 2017;14(1):9–24.
4. Bello ML, Walker AJ, McFadden BA, et al. The effects of TeaCrine® and caffeine on endurance and cognitive performance during a simulated match in high-level soccer players. J Int Soc Sports Nutr. 2019;16:20.
5. Cesareo KR, Mason JR, Saracino PG, Morrissey MC, Ormsbee MJ. The effects of a caffeine-like supplement, TeaCrine®, on muscular strength, endurance and power performance. J Int Soc Sports Nutr. 2019;16:47.
6. He H, Ma D, Crone LB, et al. Assessment of the drug–drug interaction potential between theacrine and caffeine in humans. J Caffeine Res. 2017;7(3):95–102.
7. Guest NS, VanDusseldorp TA, Nelson MT, et al. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021;18(1):1.