One of the more recent discoveries in the world of supplementation is L-Theanine, so if you are not so familiar with what this product actually is, don’t sweat it. You aren’t alone.

This aid, becoming familiar with what it can do for you is now very important. L-Theanine has some key benefits that will really help any serious lifter out and as someone who takes their results very seriously, you should be focused on anything that will help you go that extra mile.

So what is L-Theanine and what can it do for you? Why put your focus on having it?

Let’s take a closer look so you can see the big picture and determine if this is an ingredient you want in your plan.

What Is L-Theanine?

L-Theanine is a particular amino acid that is most typically going to come from tea leaves with both black tea and green tea. Studies suggest that both black and green tea components have many health benefits and part of that is to do with the levels of L-Theanine found in them.

Now however, you can also get L-Theanine in supplemental form, so there is no need to drink cup after cup of tea in order to do one.

Why Use L-Theanine?

So why use it? The biggest benefit you’ll receive upon taking L-Theanine is an overall calming effect (1).

Those who use it report feeling less overall anxiety and stress (2) compared to those who don’t use it, so if you are feeling very stressed out with any areas of your life, it can have a relaxing effect and help you feel at peace with things.

Many people have a high tendency to use L-Theanine with caffeine because caffeine does tend to increase the level of activation in the brain and can make you feel more anxiety-prone, so when you combine caffeine with L-Theanine, you get the energizing effects of caffeine but without that anxiety-like feeling that many people dislike (3).

If you ever feel jittery after using caffeine, you will find that that problem abates itself when you at L-Theanine to the mix.

What’s unique about the caffeine and L-Theanine combination is that when you use them together, you get an intense focus that’s stable, energized, and lasting. With caffeine, you get the focus, but it’s sometimes not a smooth focus. L-Theanine will help change that.

Research shows (4) that those who use L-Theanine with caffeine report having better overall levels of concentration when doing tasks than without using either caffeine alone.

On top of tall this, L-Theanine may also help to promote better overall sleep quality as well. If you want to get maximum benefits from your workout sessions, there’s no question that sleep is going to be paramount. Sleep is when you recover and repair the muscle tissues from the session prior, so without adequate sleep, recovery will start to falter.

Because L-Theanine helps to induce a calming effect on the body, it’ll help lull you into a sleep better and it can also help to reduce any stress or anxiety you might be feeling keeping you up at night.

Sleep is also important for promoting optimal body composition effects as well. When you aren’t getting enough sleep at night, your insulin sensitivity can decline, which can make you more prone to storing excess body fat from the carbohydrates you eat. Having good insulin sensitivity is paramount when cutting so poor sleep quality won’t do you any favors.

Reduced Blood Pressure

For those who tend to have high blood pressure levels, it may not be possible for them to use caffeine often because caffeine does have a tendency to increase blood pressure. The good news however is that L-Theanine will help to lower it down and therefore, make caffeine use more possible.

Or, if used without caffeine, it can offer potential blood pressure lowering effects, providing to be an alternative form of treatment in those who need it.

Do note though that if you have been advised by your doctor to really watch your blood pressure or are on blood pressure medication, you will want to speak to your treating physician before you start to consume caffeine and L-Theanine to ensure it’s safe to do so.

Dosing L-Theanine

There currently is no set dosage level for L-Theanine however the more important element is to ensure you aren’t overdosing on caffeine when using it. It appears as though anywhere from 200-400 mg of L-Theanine daily will be beneficial and will help you see great results when used in combination with caffeine.

Potential Side Effects

The good news it that there are no known or reported side effects from using L-Theanine, so it appears to be safe to consume. This said, it’s often mixed with coffee or other beverages containing caffeine and because of the calming effects it has on the mind and body, you may think that you can handle a higher dosage of caffeine.

Take caution. Too much caffeine is never a wise idea and that can come with unwanted side effects, so in reality, while L-Theanine does not pose a threat, indirectly it could if it caused you to take in too much caffeine.

High doses of caffeine are associated with nausea, stomach upset, stomach ulcers, as well as a general sense of irritability.

So do think about how much caffeine you are consuming when using L-Theanine to make sure you are still within safe limits.

L-Theanine is one of those ingredients that may not have a direct impact on your progress or body composition like say creatine, protein powder, or caffeine does, but instead, helps augment the other supplements you’re already taking and will help make your workout sessions that much more effective.

It can also make using a pre-workout supplement far more enjoyable as you won’t get that unwanted crash after using it like you do with so many others that do contain higher dosages of caffeine.


  1. Lu, Kristy, et al. “The acute effects of L‐theanine in comparison with alprazolam on anticipatory anxiety in humans.” Human Psychopharmacology: Clinical and Experimental 19.7 (2004): 457-465.
  2. Kimura, Kenta, et al. “L-Theanine reduces psychological and physiological stress responses.” Biological psychology 74.1 (2007): 39-45.
  3. Haskell, Crystal F., et al. “The effects of L-theanine, caffeine and their combination on cognition and mood.” Biological psychology 77.2 (2008): 113-122.
  4. Giesbrecht, Timo, et al. “The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness.” Nutritional neuroscience 13.6 (2010): 283-290.