L-Theanine Side Effects – Safety, Reports, and Dosages

Do you need to worry about L-Theanine side effects when using this supplement as a nootropic or for relieving stress and enhancing the mood?

In clinical studies, results have indicated that side effects from L-Theanine are essentially a non-issue. This makes sense, since people have been consuming L-Theanine for thousands of years in a very common source – green tea.

L-Theanine was first isolated in 1949 by Japanese scientists, who extracted it from green tea leaves like Camellia sinensis and gyokuro. This naturally occurring amino acid, similar to Glutamine, was found to be one of the key components that gives green tea its well-known potency as a mood lifter and concentration enhancer.

This long history of safe use grants L-Theanine a built-in safety record: through the drinking of green tea, L-Theanine has been safely consumed by humans for many thousands of years, with no side effects.

In fact, the side effects of L-Theanine are so insignificant that it has been granted Generally Recognized As Safe status (GRAS) by the United States Food and Drug Administration (FDA). Now, L-Theanine is commonly taken as a nootropic for cognitive enhancement.

L-Theanine is available in the US as a dietary supplement only, and the FDA has not approved L-Theanine as a drug to prevent or treat any conditions.

L-Theanine

Amino Acid

Focus

Stress

Brain Function

How It Works:

• Supports focus, attention & mood
• Helps to reduce stress & anxiety
• Neuroprotective & increases NGF

Dosage:

Between 100 - 250 mg per day

Safety:

Rated Possibly Safe

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Research and Reports on L-Theanine Side Effects

The vast majority of scientific studies, such as recent research at the NYU Langone Medical Center, indicate that L-Theanine is completely free of noticeable side effects.

Decades of anecdotal user reports across a broad range of online discussion groups have come to the same conclusion – L-Theanine is widely considered to be both benign and effective. Almost all reports focus exclusively on a documented list of health benefits.

These include increasing the production of GABA, a key neurotransmitter responsible for preventing over-firing of neurons in the brain. Increased GABA levels have been shown to reduce the sensations of stress and anxiety. GABA also boosts alpha waves, electrical brain signals that accompany intense focus, deep relaxation, and creativity.

L-Theanine is also a GABAergic compound, meaning it is able to interact with GABA receptors in the brain similarly to GABA itself. Finally, it has been shown that L-Theanine supplements can reduce an over-active heart rate and lower blood pressure.

Most Common L-Theanine Side Effects

The only reported L-Theanine side effects tend to be mild stomach-related discomforts connected to the delivery method of consumption, such as drinking the supplement with green tea or other caffeinated beverages, such as coffee.

The acidity of the tea or coffee can irritate the stomach and bowels for some people, resulting in diarrhea if too much is consumed. This result is rare though, and is not due to the L-Theanine itself.

It is also possible that one of the secondary effects of L-Theanine, the production of GABA, could result in some mild side effects which can be mitigated with simple moderation. L-Theanine does not cause headaches, as some nootropics can for some people.

Some readers have asked whether it is safe to combine L-Theanine and alcohol. There is no recorded negative interaction between these two substances and it is unlikely that one would experience side effects from taking them in combination. However, it is always possible that an individual may experience a unique reaction due to a personal sensitivity.

That being said, research in mice has shown that L-Theanine can actually prevent some forms of liver damage caused by alcohol. In a paper entitled, “L-Theanine prevents alcoholic liver injury through enhancing the antioxidant capability of hepatocytes,” it was found that this supplement can prevent hepatoxicity by reducing the amount of alcohol in the bloodstream.

This is not to say that similar effects would be seen in humans, and you would be taking L-Theanine together with alcohol at your own risk.

L-Theanine Side Effects And Blood Pressure

Is it possible to be too relaxed by a natural supplement? L-Theanine is frequently taken for the purpose of lowering blood pressure.

While its effects are neither extreme nor jarring to normal circulatory systems, users who already have pre-existing heart conditions or are currently on anti-hypertensive medications should check with their doctor before trying L-Theanine.

However in almost all cases, L-Theanine will not impair any physical activities which require/generate healthy cardio function, like athletics. In fact, the “peak performance” mental quality of the supplement typically helps athletes to feel more in tune with the synergistic connections between blood flow, muscle function, and mental acuity.

L-Theanine Dosages

As with all supplements, figuring out the correct dosage is the key to maximizing benefits while eliminating the risk of any unwanted L-Theanine side effects. For most people, the baseline dose of L-Theanine is 200mg per day. The effects are very gentle at this dosage, and side effects are nonexistent.

Based on body weight, sensitivity, and tolerance, many people take an average of 400mg per day, in some cases going as high as 800mg. Even at this dose, no side effects are known. L-Theanine does not create a feeling of depletion or depression once it has left the system, nor does it result in a hangover the following day.

Stacking L-Theanine With Other Supplements

To boost benefits, many people enjoy stacking L-Theanine with other supplements. Stacking simply means taking multiple different supplements as part of an overall supplement regimen. For example, L-Theanine is very commonly taken in conjunction with a caffeine supplement. This practice clearly has its roots in L-Theanine’s origin as a tea component. Does this method incur more L-Theanine side effects?

While L-Theanine would not on its own generate side effects in this combo, excessive caffeine might be an issue for people with sensitivities to the stimulant. Users who are accustomed to L-Theanine’s lack of side effects should take extra care to investigate the residual effects of all other supplements in the stack. Generally, by modifying relative dosages and listening to the body’s feedback, most of these can be negated.

Overall, L-Theanine side effects have never been a significant concern for users, either in its original form of green tea or its widespread modern use as a nootropic. A moderate dose appropriate to each individual can be enjoyed safely on a daily basis or as needed.

Free from worry about unwanted effects, users can let L-Theanine’s many benefits take center stage. Enhanced cognitive function, reduced stress and anxious thoughts, boosted creativity, and a calm mood are positive, life-enhancing benefits that make this supplement one of the most popular – and harmless – nootropics on the market.

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