Theanine vs. GABA: Why These Supplements Are So Different

Theanine is one of my favorite supplements for fighting the effects of stress — it’s a calming amino acid usually found in green tea, and recent research backs the idea that it can have an anti-stress (but not necessarily sedating) effect on the body and mind. GABA, on the other hand, is a neurotransmitter, the main one responsible for “depressing” signals in the brain. Because of its potency, GABA is often seen in sleep and relaxation supplements to calm the mind and aid sleep. But it has very poor bioavailability, meaning it’s not always effective when taken orally.

There are actually a few different versions of theanine, but l-theanine is by far the most common and most studied in regard to relaxation and anti-stress. (Check out the article I wrote on why l-theanine is preferred here.) And while l-theanine on its own isn’t necessarily a sleep supplement I recommend — remember, it’s not really sedative for many people — it does compliment other ingredients in some of my favorite sleep-enhancing products, like:

  • ZMA with Theanine (by True Athlete), full review here
  • Twilune, full review here
  • YAWN by Nootrobox, full review here
  • Alpha BRAIN by Onnit, full review here (not necessarily a sleep supplement, but very powerful for me when stacked with New Mood for overall performance, rest, and feelings of wellbeing)

Theanine compliments several other popular sleep compounds, hence its inclusion in so many stacks I like. GABA, as I mentioned above, is a little tricker: It has difficulty passing the blood-brain barrier when ingested, and the human body is also very adept at regulating its levels in the brain, meaning supplementation itself can be tough.

For a long time, GABAwave was my favorite GABA supplement, because the version it contained (phenibut) is generally considered better at crossing the blood-brain barrier. It was one of my go-tos for fighting travel stress and jetlag, but now it’s become difficult to get. As I mention at the top of my GABAwave Review, I’ve generally replaced it with New Mood as my travel sleep aid of choice.

Overall, I think we can expect to see more and more theanine-containing sleep supplements coming onto the market. In contrast, I’m seeing fewer GABA-containing supplements coming out as manufacturers grapple with the difficulty of sourcing a good, bio-available ingredient for them.


Having written hundreds of articles on, Caitlyn knows what she's talking about when it comes to getting the best night's sleep. When not sleeping, reading about sleep, or writing about sleep, you can usually find her at the gym. Want to get in touch? The best way is to leave a comment on one of her articles.