The Complete Guide to L-Theanine for Bodybuilding

As a seasoned gym goer, I’ve seen firsthand how certain supplements can help boost performance and accelerate gains.

L-Theanine is one supplement that should definitely be on your radar. It’s a natural amino acid found in green tea leaves that has a wide range of benefits for bodybuilders.

But what exactly can L-Theanine do for you? Let’s find out!

What is L-Theanine?

L-theanine is a natural amino acid, but it differs significantly from BCAAs, for example, the most popular amino acids in the fitness world.

L-theanine, or just theanine, is a non-proteinogenic, non-essential amino acid. What does it mean? Unlike proteinogenic amino acids, non-proteinogenic ones are not building blocks for protein synthesis. Many more non-protein amino acids exist than those encoded in the genetic code.

The only true natural source of theanine is green tea, and it is also present in black tea and white tea.

D-theanine is the less common form of it.

The amino acid glutamine is structurally similar to L-theanine, but the effects and benefits are not the same.

What are the Benefits of L-Theanine for Bodybuilding?

The mental aspect is often overlooked in sports and has a massive impact on success. This is precisely where L-Theanine comes into play. This amino acid may support bodybuilding in the following ways:

  • Reducing stress – Stress and anxiety have a detrimental effect on physical and mental performance. Several studies have confirmed that L-Theanine has a soothing effect on people under a lot of stress. (1)
  • Improved focus – Music, noise, or worries can come in and distract you while you’re in the gym, affecting the quality and intensity of your workout. You’ll be happy to hear that theanine can help with that. It may improve focus and attention. (2)
  • Better sleep quality – Recovery is equally important as lifting weights and having a proper diet. The body and brain regenerate best when we sleep, which is why night’s sleep is paramount. Since L-theanine can cross the blood-brain barrier, it directly affects neurotransmitters and relaxes the brain, improving sleep quality.
  • Immune system improvement – If you are often sick, you cannot have the workout routine you want. The immune system is also responsible for preventing many other diseases, not only the fight against viruses and bacteria. Theanine alone won’t do wonders for your immune system, but it will improve it along with zinc and other vitamins and minerals you should be consuming.

Does L-Theanine Help with Muscle Growth?

L-Theanine won’t directly help you with muscle growth like whey protein or creatine monohydrate.

But wait a second…

Direct influence is not the only thing that matters. Theanine will certainly affect muscle growth by giving you better focus to push through the whole workout. Later, it will make you sleep better, which is the period when muscles recover and grow.

I must also mention the mind-muscle connection, which, theanine will indirectly affect as well. (3)

Best L-Theanine Dosage for Bodybuilding

There is no L-theanine dosage recommendation since it is not a medicine, nor has research been conducted on that topic. However, an overdose is practically impossible, whether you drink green tea or take this nootropic as a supplement. (4)

Most supplements contain around 200 mg of theanine, which is considered an effective dose for every purpose.

Should You Take L-Theanine Every Day?

In general, you can take L-Theanine every day. Moderate intake is safe and well-tolerated. Also, if you skip it, nothing will happen. You don’t have to take it daily since it doesn’t need to accumulate in the body like creatine to see the benefits.

If you have pre-existing medical conditions or are taking any medication regularly, consult doctors. They will tell you whether you should take it because theanine might interact with medicines for high blood pressure and sedatives.

When is the Best Time to Take L-Theanine?

The best time of day to take L-Theanine depends on your individual needs and goals. 

For cognitive enhancement, which includes focus, attention, and mental clarity, morning and afternoon (until 5 PM) are ideal times. This will help you get through the day and give your maximum in the gym. The same applies to stress relief.

If you take L-Theanine to improve sleep, the evening is the right time. I say supplement because it is not recommended to drink green tea before bed (relatively high caffeine content.)

Is L-Theanine a Useful Ingredient in Pre-Workout Supplements?

I really like when I find L-Theanine among the ingredients of pre-workout supplements, and I’ll tell you why. The first reason is certainly all the benefits of the amino acid theanine. We all need help to deal with brain fog, which is a consequence of stress, lack of sleep, and too much work.

But that’s not all. L-Theanine and caffeine, an essential pre-workout ingredient, work more effectively together than when taken separately. You will notice a huge focus improvement when both are part of a pre-workout supplement. Simultaneously, L-Theanine will reduce the side effects of caffeine, such as edginess, anxiety, tachycardia, and higher blood pressure.

Does L-Theanine Have Any Side Effects?

Here’s the best part – L-Theanine is completely safe and natural. Unlike some other supplements with a laundry list of side effects, L-Theanine is gentle on your body and doesn’t cause any unwanted jitters or crashes.

If green tea is your source of theanine, it may be responsible for mild side effects, like irritability and insomnia.

Are L-Theanine Supplements Worth it for Bodybuilding?

It’s important to note that the effects of L-Theanine on exercise performance are still being studied. Nevertheless, the impact on cognitive abilities and sleep has been proven, which suggests that L-Theanine supplements are undoubtedly worth it for bodybuilding. And that’s why I would advise taking this brain supplement.

But before you run out to the store to pick up some L-Theanine, I want to remind you of one thing: supplements are just one piece of the puzzle. The key is consistency and hard work.

No supplement can replace dedication, discipline, and a solid workout routine. So, keep hitting the gym, fueling your body with healthy foods, and pushing yourself to new limits. And with the assistance of L-Theanine, you’ll be unstoppable.


Alright, fitness fanatics, we’ve covered a lot of ground today when it comes to L-Theanine and how it can benefit you in your bodybuilding journey.

Remember, L-Theanine is a safe and natural way to improve your focus, mood, and cognitive function during workouts and the rest of the day. It’s a powerful tool to help you break through plateaus and achieve your goals faster.

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Pierce Reiten
Pierce Reiten

Pierce Reiten is an NASM certified personal trainer with over a decade of experience in the gym. He's passionate about providing information to help you improve your fitness and life.

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