L-theanine and caffeine have both become quite popular because of their benefits for focus and motivation. However, if you’ve spent any time around supplements, then you already know that some pairings play nice while others tend to cancel each other out (or worse).

When you’re risking two supplements canceling each other out, it truly does pay to do your homework and ensure you land on a combo that takes each supplement’s benefits to the next level. Luckily, that’s exactly how caffeine and L-theanine interact. In this article, we’ll discuss their benefits, why taking them together works so well, and how to do it.

What Is L-Theanine?

L-theanine is an amino acid naturally found in tea leaves, especially green and black tea. Unlike proteins your body uses to build muscle, this non-dietary amino acid works directly on your brain chemistry. 

Research suggests it supports the production of alpha brain waves, which are linked to a calm but alert state of mind. L-theanine also interacts with neurotransmitters like GABA, dopamine, and serotonin, which influence mood, relaxation, and mental clarity. That’s why drinking tea often feels less like a caffeine jolt and more like a steady hum of focus. 

What Is Caffeine?

Caffeine, on the other hand, is the life of the party. Found in coffee, tea, energy drinks, and even chocolate, it’s the world’s most widely used stimulant. Caffeine works by blocking adenosine receptors in the brain. Normally, adenosine tells your body it’s time to rest and chill. Block that signal, and suddenly you’re wide awake, alert, and ready to answer emails you’ve been avoiding since last Tuesday. 

But caffeine isn’t all sunshine and rainbows — it’s also notorious for side effects like jitters, a racing heart, nausea, or that awkward 3 P.M. crash. Still, in moderate amounts, caffeine sharpens reaction time, boosts focus, and keeps fatigue at bay. That’s why billions of people (literally) rely on it to kickstart their mornings or push through late nights. 

Benefits of L-Theanine vs. Caffeine

If you’re anything like us, sometimes seeing something laid out in order can help make things make sense. That’s why we’ve created the following table to help you understand some of the key differences between L-theanine and caffeine:

Can You Combine L-Theanine and Caffeine?

So, here’s the real question — if these two supplements are so different, can you take them together? We’re pleased to tell you that the answer is a resounding “yes.” 

In fact, many people intentionally combine these supplements because they can have a synergistic effect. Here’s what we mean.

Supports Focus

One of the biggest perks of pairing L-theanine with caffeine is the way it supercharges your ability to stay focused. On its own, caffeine gives you the alertness boost you need, but it can sometimes scatter your attention in too many directions. 

L-theanine helps filter out the mental “noise” thanks to its interactions with alpha brain waves, which are linked to calm concentration. Together, they create what researchers call “relaxed alertness” — a sweet spot where your brain is fully engaged but not overstimulated. 

Encourages a Good Mood

Coffee can get you fired up, but sometimes it also stirs up anxiety, irritability, or jitters. L-theanine helps balance things out by encouraging neurotransmitters like dopamine and serotonin, which play a big role in regulating mood. The end result is a caffeine high that feels steadier and more enjoyable. 

Supports Mental Speed and Accuracy

Speed without accuracy is chaos, but accuracy without speed isn’t much better. That’s where the L-theanine-and-caffeine duo really shines. Studies suggest the combo can support reaction times and help you process information quickly without increasing error rates. 

Caffeine alone can make you quicker, but sometimes at the cost of sloppy mistakes. L-theanine helps tighten the reins, so you’re not just working fast — you’re working smart. 

Do L-Theanine and Caffeine Cancel Each Other Out?

The good news is that they don’t cancel each other out. In fact, they balance each other out. Studies show that when combined, L-theanine helps reduce caffeine’s less-welcome side effects like jitters, nervous sweating, and anxious thoughts. So, while L-theanine can dampen some of caffeine’s effects, trust us — it’s for the best.

How To Combine Them

Traditionally, people combine L-theanine and caffeine by pairing a supplement with a morning coffee or by drinking matcha, which naturally contains both. But if you want a ready-made, science-backed solution, our Mushroom Coffee+ was designed with this balance in mind.

Each serving has 45 mg of caffeine (about half a small cup of coffee), plus L-theanine to smooth out the energy curve. That means you get focus and alertness without the crash, gastrointestinal distress, or anxiety often tied to higher caffeine doses. But the formula doesn’t stop there.

We’ve also included the following ingredients in every spoonful:

• Lion’s mane mushroom to support memory, creativity, and overall brain health.
• Chaga mushroom provides antioxidants and helps support the immune system.
• Collagen protein to encourage gut health, skin, and joints.

Together, these ingredients can support focus, gut health, skin health, and even your sleep, all without sacrificing that sacred coffee flavor. And while we love a good cup of plain mushroom coffee, there are also plenty of recipes you can try if you prefer different flavors or textures.

Safety Tips 

While both L-theanine and caffeine are generally safe in moderate amounts, it’s still smart to use them wisely. First, start small. Too much caffeine can still lead to insomnia, anxiety, or a racing heart, even with L-theanine’s help. 

Pregnant or breastfeeding individuals, or anyone with conditions like low blood pressure, should also check in with a healthcare provider before experimenting. And remember that supplements aren’t regulated by the FDA the same way medications are, so stick with trusted brands that hold themselves accountable with third-party testing.

The Bottom Line

When it comes to focus, caffeine might be the spark, but L-theanine is what keeps it all from going up in flames. This combo can support attention, mood, and accuracy, all without leading to jitters or afternoon crashes. 

That’s a huge reason we included both L-theanine and low-caf coffee extract in our Mushroom Coffee+. We’d say “trust us,” but we know sometimes you just need to see it for yourself. So, check out our collection of mushroom blends, and when you feel the difference, we won’t say we told you so.

Sources:

L-theanine, a natural constituent in tea, and its effect on mental state | PubMed

How does the tea L-theanine buffer stress and anxiety | ScienceDirect

Adenosine, caffeine, and sleep–wake regulation: state of the science and perspectives | PMC

Caffeine Reduces Reaction Time and Improves Performance in Simulated-Contest of Taekwondo | PMC

Effect of single or combined caffeine and L-Theanine supplementation on shooting and cognitive performance in elite curling athletes: a double-blind, placebo-controlled study | PMC

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 | PMC