Skip to Content

L-Theanine vs GABA – Which One Should You Take?

I may receive a commission for purchases made through product links on this page, but I always stand by my opinions and endorsements!

Both L-Theanine and GABA have a lot to offer and I really like both of them. But since they’re quite similar, it might be hard for people to decide between them.

Well if that’s you, then you’ve come to the right place.

This is the exact reason I started this Supplement Comparison Series! In these articles, I pit 2 supplements against one another and compare them on benefits, price, side effects, and much more.

All so you can make a more informed decision.

In this piece, we’ll take a look at L-Theanine vs GABA.

Let’s take a closer look.

What is L-Theanine?

L-theanine is a “calming” amino acid that’s found in tea leaves.

So for most people, tea is the most common source of L-Theanine.

To be even more specific, real green tea is the most common source of L-Theanine.

If you’ve ever tried real green tea (not the tacky stuff Lipton makes), then you probably know just how great l-theanine makes you feel:

  • Calm
  • Relaxed
  • Focused

L-Theanine is amongst my favorite brain-boosting ingredients, as it’s relatively safe, healthy and effective.

What is GABA?


GABA (Gamma-Aminobutyric acid) is an amino acid that’s naturally produced in the brain.

It works as a neurotransmitter, facilitating communication among brain cells.

GABA’s main role is to reduce the activity of neurons in the brain and central nervous system, which has a wide range of effects on the mind and body, including:

  • Reduced stress
  • Improved sleep
  • Improved mood
  • Increased relaxation

Many anxiety medications, including Valium and Xanax work by increasing GABA in the brain.


Benefits of L-Theanine

L-Theanine improves cognitive function

L-Theanine works as a nootropic – another way of saying a “smart drug”.

But before you panic at the word “drug”, rest assured that L-Theanine is 100% legal.

It works by amplifying your Alpha brain waves, which help increase creativity.

I can vouch for this as my best work is done a few hours after I supplement with L-Theanine.

L-Theanine helps reduce caffeine jitters

Now I don’t know about you, but my favorite time of day is that first sip of a warm, black coffee.

The one that instantly puts a smile on your face, even if it’s a Monday morning.

Nothing compares to that feeling.

But sometimes, my morning coffee can be overwhelming.

Anxiety, jitters and headaches are just a few of the noticeable effects of consuming too much caffeine.

But since taking L-Theanine in the morning, these side effects are barely noticeable for me!

L-Theanine helps improve sleep

Over the last year or so, I’ve tried a few different supplements to improve my sleep quality, including Holy Basil, L-Theanine, California Poppy Extract and Phosphatidylserine.

I’ve had great results with all but California Poppy Extract.

My usual combination is Holy Basil and Phosphatidylserine, but when I swapped this for just L-Theanine, my sleep was as good as ever.

I measure my sleep quality on 2 variables:

  • How deep my sleep is
  • How fast I can fall asleep

For me, L-Theanine improved both of these metrics.


Well it helps me fall asleep faster by calming my mind, thus reducing overthinking, and it helps me enter a deep sleep by increasing alpha brain waves.

Benefits of GABA

GABA helps improve sleep

GABA allows the body and mind to relax and fall asleep, and so low GABA activity may cause disrupted sleep.

This theory has been backed up research, where people with insomnia had almost 30% lower GABA levels than those without it.

Another study showed that 100mg of GABA shortened the time it took subjects to fall asleep by 5.3 minutes.

(Related reading: Do Cold Showers Help You Sleep?)

GABA helps reduce anxiety and stress

Want to know a shocking fact?

More than 40 million (yep… million) US adults are affected by anxiety.

(This makes anxiety the most prevalent mental condition in America.)

The good news is that numerous studies have shown just how effective GABA is at reducing anxiety and stress.

For example, a study of 13 adults investigated the effects of oral GABA on relaxation.

The results showed that after 60 minutes of ingesting GABA, the subjects had increases in slow brain waves which helped them relax and reduced their anxiety.

Another study investigated the effects of GABA on stress levels during a mentally challenging task.

Compared to those who took the placebo, the GABA users had a smaller decrease in slow brain waves, suggesting it may have alleviated their stress from the task.

(Related reading: Do Cold Showers Help Anxiety?)

GABA may reduce high blood pressure

Research shows that GABA may be effective at reducing high blood pressure.

In one study of people with high-normal blood pressure, 12 weeks of supplementing with chlorella significantly lowered their blood pressure.

(Chlorella is a type of algae that’s rich in GABA.)

For this reason, some people use GABA supplements as a natural way to lower blood pressure.


L-Theanine Cost

L-Theanine is usually sold as a powder or in capsules.

Typical prices for these are:

  • Powder: $10 for 100g
  • Capsules: $20 for 100


Like L-Theanine, GABA is typically sold in the form of powder or in capsules.

Here are some standard prices for these:

  • Powder: $20 for 1 lb
  • Capsules: $22 for 100

Side Effects

L-Theanine Side Effects

Very few, if any!

Generally speaking, it’s safe to supplement with L-Theanine and drink teas that contain L-Theanine.

But if you drink too much tea, you may experience the following due to large amounts of caffeine:

  • Nausea
  • Irritability
  • Upset stomach

GABA Side Effects

Although GABA supplements are usually well tolerated by healthy adults, some people have reported experiencing the following side effects:

  • Nausea
  • Constipation
  • Muscle weakness
  • Diminished appetite
  • Drowsiness and fatigue


My L-Theanine Recommendation: Nootropics Depot L-Theanine Powder

Nootropics Depot L-Theanine Powder

Click to see on Amazon


An excellent source of L-Theanine that comes in powder form.

Great for those who enjoy having the freedom to choose how much L-Theanine they want to take.

What I like about it

Nootropics Depot L-Theanine powder is 100% pure L-Theanine.

That’s right.

No fillers. No nasty chemicals. No preservatives.

Just 100% L-Theanine goodness.

I also love how each tub contains a whopping 2500 servings, so this bad boy will literally last you years.

And since it’s a powder, you can easily change the dosage to suit your needs.

Potential Drawbacks

As it’s a powder, some people may not like the taste and thus prefer capsules.

But as the saying goes: Don’t knock it until you’ve tried it.

Check price and read more reviews of Nootropic Depot L-Theanine Powder on Amazon.

My GABA Recommendation: Thorne Research PharmaGABA-100

Thorne Research PharmaGABA-100

Click to see on Amazon


One of the highest-quality GABA supplements available.

So, if you value quality then you should consider going with these capsules.

What I like about it

Dozens of excellent reviews show that this is a trusted GABA product that’s extremely helpful to many people.

And unlike many other GABA supplements out there, this supplement is made from PharmaGABA.

(PharmaGABA is naturally made with lactobacillus hilgardii, which is a type of bacteria that’s often used to make kimchi.)

Clinical studies have shown that PharmaGABA is much more effective than synthetic GABA.

Also, the Thorne Research company provides some of the best, pharmaceutical-grade supplements on the market.

(You can read more about Thorne Research’s quality control process if you want to know more.)

Potential Drawbacks

Thorne’s supplements are typically more expensive than other brands.

But, I’ve always felt like I got my money’s worth after using Thorne’s products.

Check price and read more reviews of Thorne Research PharmaGABA-100 on Amazon.

L-Theanine vs GABA: The Verdict

Well, I hope you’ve enjoyed reading this L-Theanine vs GABA breakdown.

They’re both great supplements that aren’t too expensive and offer so many benefits.

So, here’s my basic guide to how I would make this decision, if I were you:

You might prefer L-Theanine if:

  • You hate caffeine jitters
  • You want a cognitive boost
  • You don’t want any possible side effects

You might prefer GABA if:

  • You want to reduce anxiety and stress
  • You want to lower your blood pressure

Hope this helped!

You might also find these articles interesting…

Julia Durning

Friday 24th of July 2020

I am tapering off Xanax. I was at 3.5 -4 mg a day (great doctors that would rather up the Xanax than treat my anxiety) and after a year and a half of tapering, I am now down to 1 mg. I have to break my pills so I can dose 4 times a day. If I do not do this I have terrible interdose withdrawal. I was on the high dose for over 2 years and I should have never been put on it. I was cold turkeyed off by a MD who knew nothing about this drug and it almost killed me and so I was put back on the Xanax to get me stabilized. That took over a year. I have found a psychiatrist nurse who is helping me get through the last 1 mg and it is so hard. The lower I go, the harder it gets and longer it takes which is depressing but I am still going to do this. The nurse suggested I add L-Theanine each day to help with the anxiety i have and the withdrawal I have. My question is, how to do this? I tried taking 200 mg for 3 days straight with my morning coffee. I get up, take the dose of Xanax (.25 mg) then take the L-Theanine and drink 1 cup of coffee. The third day I did this, OMG, I got so anxious, irritated and easily annoyed that it scared me! I was angry and wanted to throw something. I called the nurse and she said it sounded like I was over stimulated. How do I incorporate this while taking the Xanax? She said take it in the afternoon but with me taking my doses at 9 am, noon, 4 pm and 8:30 pm, I do not know what to do. I want to try this as I want off this Xanax so bad and I believe the L-Theanine will help but do not know how. Do you have any ideas? Thanks


Saturday 25th of July 2020

Hi Julia,

Thanks for sharing your story.

As I'm not a medical doctor, unfortunately I can't give you any advice on this.

But I would listen to what your nurse is saying.

Stay strong, you can do this!