Some things were just made for each other: salt and pepper, peanut butter and jelly, chocolate and…pretty much anything. Alone, these items are just fine, but together, they enhance each other’s best qualities. Nootropics can have similarly beneficial relationships.
The perfect pair of ingredients in a nootropic stack can enhance not only the ingredients’ effects but also the overall cognitive benefits you can enjoy. It’s like a match made in heaven (if you count a bright white laboratory). One such relationship between an amino acid and an alkaloid is like a modern-day Romeo and Juliet romance. But unlike the tragic ending of Shakespeare’s classic tale, the story between L-theanine and caffeine is just beginning.
Before we dive into the sweet synergy between caffeine and L-theanine, we should talk about their best qualities as individuals. We’ll start with the more familiar of the two: caffeine.
Coffee. We were all thinking it because we’re all using it; about 64% of Americans reported drinking at least one cup of coffee every day. But caffeine is found in over sixty other plants, including tea leaves, kola nuts, and cocoa beans.1 Add the synthesized version to these natural sources and you get numerous caffeine-rich foods and medications on the market. You probably know the usual suspects: chocolate, energy drinks, sodas. Even painkillers contain a small dose.
Don’t let that fact keep you up at night; just do a quick scan of the label for any caffeine culprits.
Even if it’s not an essential part of your daily routine, you probably know the basics of caffeine. Caffeine is a crystalline compound that occurs naturally and can be synthesized in a laboratory.
It stimulates the central nervous system in as little as fifteen minutes, providing you with that signature boost.
In order to function as a stimulant, though, caffeine actually has to inhibit certain actions in the brain. As countless neurons fire throughout the day, a neurochemical called adenosine builds up. The build-up of adenosine reduces neuronal activity, which causes you to feel less alert. Because caffeine is the same size and shape of adenosine, it can actually mimic it, preventing it from interacting with neurons and slowing down their activity; this is what gives us that boost.
Even when it’s not in coffee, caffeine is a hot topic. It has many benefits, and consequently, many side effects.
Caffeine may boost your memory,2 help you power through your strength3 and endurance workouts,4 and even decrease the odds of developing certain types of cancer.5 But it can also raise your blood pressure,6 increase anxiety,7 and give you a case of the jitters.8 Caffeine is also a diuretic, which will cause you to urinate more frequently to help rid your body of excess water and salt.9
We have plenty of stimulating supplement resources. Sign up now for the latest nootropic news to enjoy alongside your daily caffeine.
If you prefer to enjoy your caffeine in the form of tea instead of coffee, you’re already familiar with caffeine’s amino acid ally, L-theanine.
L-theanine is a non-protein amino acid that supplies the mouth-filling umami flavor of green tea and black tea.10
L-theanine can reduce our physiological stress responses by imitating the actions of gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter that blocks excitatory responses in the brain. L-theanine can also suppress excitatory glutamatergic receptor function. By inhibiting excitatory responses, L-theanine can lower your blood pressure,11 heart rate, and stress hormone levels.12 Reduce these responses, and you get an overall reduction in stress and anxiety.
While you’re winding down, L-theanine can help your brain generate alpha brain waves associated with relaxing activities such as daydreaming and meditation.13 Fully relaxed? L-theanine’s prolonged calming effect could edge you that final step toward sleep,13 which is why HVMN added it to the mix for our non-habit forming sleep aid, Yawn. Yawn can help you fall asleep faster,14 experience higher quality sleep,15 and wake up feeling revitalized.16
L-theanine works on both sides of the sleep cycle. Once you’re awake, you can take L-theanine to start your day focused; human subjects performed attention tasks better17 after supplementing with L-theanine.18
Every great relationship needs a solid foundation to work. And work is exactly what L-theanine and caffeine must do to maintain their caring connection. But hard work is not a guarantee that everything will go as planned. In this section, we’ll explore the couple’s biggest triumphs as well as their biggest obstacles.
We know about caffeine’s worst attributes: anxiety, restlessness, increased blood pressure. Like any good partner, L-theanine does its best to correct these qualities for everyone to enjoy caffeine’s company a little more easily.
Caffeine inhibits the actions of our adenosine receptors in the brain, which is the stimulatory activity. L-theanine can help reduce physiological responses to stress by inhibiting excitatory responses in the brain
When these two meet, they don’t just fight each other to stalemate–instead, they work out a compromise.
L-theanine has been shown to allow caffeine to work its brain-boosting charm without letting it raise your blood pressure or induce anxiety.18
Caffeine is a vasoconstrictor. These temporarily make blood vessels smaller, which raises your blood pressure to account for reduced blood flow. L-theanine eliminates caffeine’s vasoconstrictive tendencies so you can focus on something other than the sound of the blood pumping in your ears.18 If you can’t focus on anything because caffeine crashes leave you with headaches and fatigue, bringing L-theanine along may be able to help; human subjects in a 2008 study reported fewer headaches and less tiredness when mixing the two compared to taking caffeine by itself.19
For some, having a cup of coffee after 3pm will keep them up all night. Caffeine can be beneficial or annoying, depending on time of day. L-theanine knows how to calm caffeine down to help attenuate its adverse effects on your sleep schedule.20
More specifically, L-theanine targets caffeine’s propensity toward reducing your slow-wave sleep, which is the deepest form of non-REM sleep. Getting adequate slow-wave sleep in addition to your REM sleep will result in better overall sleep quality, so you’re less likely to have to rely on caffeine the next day.
It can be difficult to work with a partner, but caffeine and L-theanine have found their mechanisms. Their groove of working together can be beneficial to help you find your groove.
Like by significantly improving reaction times.17 In one study, subjects improved their reaction times for delayed word recognition.17 In another, subjects reduced the amount of time it took to respond to flashing light cues on a computer, which suggests an improvement in acute attention.21
Even switching attention between tasks benefitted from the L-theanine and caffeine stack,22 further supporting an overall increase in focus and alertness.23 Being able to focus on a task is only half the battle; accomplishing the task well is just as important–and this happy couple can offer their support. In a 2008 study, subjects enjoyed a significant improvement in task accuracy,17 while in 2010, the caffeine-theanine induced improvement in task accuracy was reproduced, especially for the most cognitively demanding tasks.24
Demanding or not, being able to correctly complete a task only works if you don’t get distracted by a million other stimuli.
Don’t worry; L-theanine and caffeine can reduce your susceptibility to these distractions to really help you hone in on your work.23 That's why HVMN introduced the couple to fatigue-busting ginseng in Sprint. Sprint is a nootropic stack with an L-theanine and caffeine combination designed to boost cognitive function25 and overall mental performance for up to six hours. You'll enjoy increased productivity and focus22 without any jitters, anxiety,26 or other negative effects typical of caffeine alone.
L-theanine and caffeine have done some great things together, but they’re not a perfect couple. Sometimes, they fall out of sync. While many studies have shown promising effects of the dynamic duo, not all research has been able to reproduce the same results.
Take alertness, for example; in some cases, no significant increase in subjective alertness was found.22 Similarly, L-theanine and caffeine did not deliver on their natural chemistry in prolonged and monotonous tasks requiring constant attention.27 The couple also didn’t show up for mood modifications,11 with mood remaining unfazed by their interaction.17
Their interaction could be the downfall of their coupling for some; because L-theanine can modulate the stimulatory effects of caffeine, it may be mitigating caffeine’s cognitive benefits.28 The possibility of reducing caffeine’s stimulatory effects could prove even more of a problem for those who are habitual caffeine users because they’ve already lost much of their sensitivity to it.29
Despite their trials and tribulations, this synergistic couple will continue pressing on as research continues. Will they make it? The results are promising.
When supplementing with the duo on a daily basis, you can safely take 100mg - 200mg L-theanine and up to 400mg caffeine, according to the FDA.
L-theanine should not be mixed with medications for blood pressure because it can reduce your blood pressure. Otherwise, L-theanine is not currently associated with any other negative effects or symptoms. Always consult your healthcare professional before starting any new supplements.
Whether you're looking to increase your cognitive performance or just calm your caffeine nerves, getting ahold of these supplements may be able to help. Caffeine's stimulation and L-theanine's calming support can put you in the ideal mental flowstate, a feeling like you can get anything done.
Our supplement guides walk you through the best ways to hack your own brain. Sign up now for your first dose.
|1.||Gilbert RM. Caffeine consumption. Prog Clin Biol Res.1984;158:185-213.|
|2.||Borota D, Murray E, Keceli G, et al. Post-study caffeine administration enhances memory consolidation in humans. Nat Neurosci. 2014;17(2):201-3.|
|3.||Astorino TA, Rohmann RL, Firth K. Effect of caffeine ingestion on one-repetition maximum muscular strength. Eur J Appl Physiol. 2008;102(2):127-32.|
|4.||Desbrow B, Biddulph C, Devlin B, Grant GD, Anoopkumar-dukie S, Leveritt MD. The effects of different doses of caffeine on endurance cycling time trial performance. J Sports Sci. 2012;30(2):115-20.|
|5.||Poole Robin, Kennedy Oliver J, Roderick Paul, Fallowfield Jonathan A, Hayes Peter C, Parkes Julie et al. Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes BMJ 2017; 359 :j5024|
|6.||Renda G, Zimarino M, Antonucci I, et al. Genetic determinants of blood pressure responses to caffeine drinking. Am J Clin Nutr. 2012;95(1):241-8.|
|7.||Rogers PJ, Hohoff C, Heatherley SV, et al. Association of the anxiogenic and alerting effects of caffeine with ADORA2A and ADORA1 polymorphisms and habitual level of caffeine consumption. Neuropsychopharmacology. 2010;35(9):1973-83.|
|8.||M J SHIRLOW, C D MATHERS; A Study of Caffeine Consumption and Symptoms: Indigestion, Palpitations, Tremor, Headache and Insomnia, International Journal of Epidemiology, Volume 14, Issue 2, 1 June 1985, 239–248, https://doi.org/10.1093/ije/14.2.239|
|9.||Reyes CM, Cornelis MC. Caffeine in the Diet: Country-Level Consumption and Guidelines. Nutrients. 2018;10(11)|
|10.||Borzelleca JF, Peters D, Hall W. A 13-week dietary toxicity and toxicokinetic study with l-theanine in rats. Food Chem Toxicol. 2006;44(7):1158-66.|
|11.||Rogers PJ, Smith JE, Heatherley SV, Pleydell-pearce CW. Time for tea: mood, blood pressure and cognitive performance effects of caffeine and theanine administered alone and together. Psychopharmacology (Berl). 2008;195(4):569-77.|
|12.||Kimura K, Ozeki M, Juneja LR, Ohira H. L-Theanine reduces psychological and physiological stress responses. Biol Psychol. 2007;74(1):39-45.|
|13.||Raj Juneja Lekh, Chu Djong-Chi, Tsutomu Okubo T, Nagato Yukiko, Yokogoshi Hidehiko. L-theanine – a unique Amino acid of green tea and its relaxation effect In humans. Trends in Food Science & Technology 1999 (10) 199-204. 10.1016/S0924-2244(99)00044-8.|
|14.||Inagawa K, Hiraoka T, Kohda T, Yamadera W, Takahashi M. Subjective effects of glycine ingestion before bedtime on sleep quality. Sleep and Biological Rhythms. 2006; 4 (1), 75-77|
|15.||Brzezinski A, Vangel MG, Wurtman RJ, Norrie G, Zhdanova I, Ben-Shushan A, Ford I. Effects of exogenous melatonin on sleep: a meta-analysis. Sleep Med Rev. 2005 Feb;9(1):41-50.|
|16.||Bannai M, Kawai N. New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep. J Pharmacol Sci. 2012;118(2):145-8.|
|17.||Haskell, C. (2008) The effects of l-theanine, caffeine and their combination on cognition and mood. Biological Psychology Volume 77, Issue 2, February 2008, Pages 113-122|
|18.||Dodd, F. (2015). A double-blind, placebo-controlled study evaluating the effects of caffeine and L-theanine both alone and in combination on cerebral blood flow, cognition and mood. Psychopharmacology Volume 14, Issue 232, March 2015, Pages 2563–2576.|
|19.||Owen GN, Parnell H, De bruin EA, Rycroft JA. The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutr Neurosci. 2008;11(4):193-8.|
|20.||Jang HS, Jung JY, Jang IS, et al. L-theanine partially counteracts caffeine-induced sleep disturbances in rats. Pharmacol Biochem Behav. 2012;101(2):217-21.|
|21.||Kahathuduwa CN, Dassanayake TL, Amarakoon AMT, Weerasinghe VS. Acute effects of theanine, caffeine and theanine-caffeine combination on attention. Nutr Neurosci. 2017;20(6):369-377.|
|22.||Einöther SJ, Martens VE, Rycroft JA, De bruin EA. L-theanine and caffeine improve task switching but not intersensory attention or subjective alertness. Appetite. 2010;54(2):406-9.|
|23.||Bryan J. Psychological effects of dietary components of tea: caffeine and L-theanine. Nutr Rev. 2008;66(2):82-90.|
|24.||Giesbrecht T, Rycroft JA, Rowson MJ, De bruin EA. The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness. Nutr Neurosci. 2010;13(6):283-90.|
|25.||Camfield DA, Stough C, Farrimond J, Scholey AB. Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis. Nutrition reviews. 2014; 72(8):507-22.|
|26.||Ellis JM, Reddy P. Effects of Panax ginseng on quality of life. Ann Pharmacother. 2002;36(3):375-9.|
|27.||Foxe JJ, Morie KP, Laud PJ, Rowson MJ, De bruin EA, Kelly SP. Assessing the effects of caffeine and theanine on the maintenance of vigilance during a sustained attention task. Neuropharmacology. 2012;62(7):2320-7.|
|28.||Kakuda T, Nozawa A, Unno T, Okamura N, Okai O. Inhibiting effects of theanine on caffeine stimulation evaluated by EEG in the rat. Biosci Biotechnol Biochem. 2000;64(2):287-93.|
|29.||Kelly SP, Gomez-ramirez M, Montesi JL, Foxe JJ. L-theanine and caffeine in combination affect human cognition as evidenced by oscillatory alpha-band activity and attention task performance. J Nutr. 2008;138(8):1572S-1577S.|
Once a week, we'll send you the most compelling research, stories and updates from the world of human enhancement.