What Does L-Theanine Do in Pre-Workout? – Complete Research

If a black coffee just isn’t cutting it to get you prepared for a heavy weightlifting session, you may find yourself searching for a pre-workout supplement that offers some extra perks. Many of these additives will be stimulants or amino acids, and L-theanine is a great option to explore.

What is L-Theanine?

L-theanine is an amino acid that is naturally occurring. Most amino acids will be found in protein sources like meat and dairy, but L-theanine is a rare exception: it can be found in green and black teas and even some mushrooms.

L-theanine is not a sedative, but it is heavily linked to stress and anxiety reduction. Those that consume it regularly are often reporting better quality and more restful sleep as well. 

Paired with caffeine, L-theanine is also linked to increased focus. [1] This is probably due to its calming effects, which help to clear the mind. This, coupled with a caffeine boost, can lead to a clear head and more productivity, which is why it is commonly found in pre-workout supplements.

What Does L-Theanine Do When Taken Pre-Workout?

When searching for a pre-workout that contains L-theanine, you will likely see them with a high caffeine content. This pairing, mentioned above, is ideal for a bodybuilder. The mind-muscle connection is imperative for a workout as it leads to better form and a lower risk of energy. For those that use the gym as a form of stress relief, the L-theanine will be a welcome addition to help with clearing the mind.

The synergistic effect that occurs when coupling L-theanine with caffeine leads not only to better focus when in the gym, but the prevalence of L-theanine in the body is linked to a higher quality of sleep. [2] Better rest means an athlete’s body will recover much more quickly.

Benefits of Taking L-Theanine Pre-Workout

The combination of L-theanine and caffeine, the building block of many pre-workout supplements, is often referred to as “smart caffeine.” While caffeine alone can be a great tool, the unpleasant side effects, like feeling jittery or scatterbrained, can sometimes harm a workout even despite the energy boost. The addition of L-theanine can cut those unpleasant side effects significantly.

L-theanine is also closely linked to supporting the immune system and helping people to avoid illness. For the bodybuilder that turns to a pre-workout supplement during cutting phases where they get natural energy from carbohydrates, this immune boost is great news. [3] These phases of extreme caloric deficit are when a bodybuilder is most likely to fall ill, which can slow their progress toward ideal stage weight and body composition.

Does L-Theanine Help with Muscle Growth?

L-theanine is not directly linked to muscle building or protein synthesis the way many other amino acids are. Despite this, many of the benefits of ingesting L-theanine do help with muscle growth goals. 

Increased focus and a calm mind in the gym make workouts more efficient and less prone to causing injury (which would cause an athlete to need to take time off for recovery and thus take time away from reaching goals).

How Much L-Theanine Should be in Pre-Workout?

The average recommended dosages for L-theanine are not exact but often range from 50 to 200 milligrams per day. It is also a supplement that is found to be perfectly safe when taken long-term, so there is no need to cycle on and off like there is with some stimulants or pre-workout additives like niacin.

Like any other supplement, start at the low end and work your way up in your dosing until you find the ideal intake for your individual needs.

How Long Does it Take for L-Theanine to Kick In?

L-theanine can take between 30 minutes to one hour for most people to notice the effects, so it is a great choice to take at home before driving or commuting to the gym. The calming and mind-stilling effects can also be noticed by athletes for up to 8-10 hours after consumption.

Does L-Theanine Have Any Side Effects?

L-theanine is not directly linked to any notable adverse side effects. That said, it is most commonly consumed in caffeinated teas and pre-workout supplements. An indulgence in either can come with side effects related to over-caffeination, like anxiety, restlessness, headache, irritability, irregular heartbeat, GI upset, and poor sleep.


L-theanine is a great supplement to experiment with because of its calming effects on the mind and body. Like any supplement, consider starting with half doses in the beginning and working your way up incrementally to judge the effects on your system accurately.

Strong mental fortitude, higher-quality sleep, and better focus during workouts are all great building blocks for bodybuilders and weightlifters that are looking to up their game.

What to Read Next

Can I Take L-Theanine and Magnesium Together?
Can I Take L-Theanine and Magnesium Together
Should You Take L-Theanine and Melatonin for Sleep?
L-Theanine and Melatonin for Sleep
Share This Post

Providing you with the resources to build your best life and physique.

Articles: 125

Leave a Reply

Your email address will not be published. Required fields are marked *