
A new paper published in Life Sciences reports that a combination of GABA (γ-aminobutyric acid) and 5-HTP (5-hydroxytryptophan) improved sleep and sleep duration more than the use of either of the two amino acids alone.
Insomnia is a common symptom of both low GABA and low serotonin. The amino acid GABA raises levels of GABA, our calming brain chemical/neurotransmitter. 5-HTP is one of the amino acids that raises serotonin, your happy brain chemical/neurotransmitter (which is also happens to be calming) and in turn converts to melatonin to help you sleep. Tryptophan is the other amino acid that raises serotonin.
Low levels of both brain chemicals can also make you anxious, worried and overwhelmed. With low GABA levels you’ll have physical anxiety and may lie awake in bed feeling tension in your body. With low serotonin you’ll have the busy-mind type of anxiety, often lying in bed not able to switch off the ruminating thoughts or monkey-mind. (You can find the complete amino acid questionnaire here.)
The study, Sleep-promoting effects of a GABA/5-HTP mixture: Behavioral changes and neuromodulation in an invertebrate model, used caffeine treated fruit flies and:
Behavioral assays were applied to investigate subjective nighttime activity, sleep episodes, and total duration of subjective nighttime sleep of two amino acids and GABA/5-HTP mixture
In case you’re wondering, fruit flies are often used in research. This paper shares that the “Homeostatic and circadian regulation in Drosophila are comparable to findings from mammalian sleep research.” I can’t help chuckling when I imagine these little fruit flies lying in a tiny bed, ramped up on caffeine and with busy little minds!

After my attempt at some humor (laughter is good for us too!), let’s get on to the serious stuff.
The study concludes that:
using a GABA/5-HTP mixture modulates subjective nighttime activity, sleep episodes, and total duration of subjective nighttime sleep to a greater extent than single administration of each amino acid, and that this modulation occurs via GABAergic and serotonergic signaling.
How this might equate to human dosing and other possible combinations
You may be wondering how this might equate to human dosing of these amino acids. Since it was the combined use of 1% GABA and 0.1% 5-HTP that had the most impact, this could equate to:
- 250mg GABA and 25mg 5-HTP or
- 500mg GABA and 50mg 5-HTP or
- 1000mg GABA and 100mg 5-HTP
Do keep in mind that we are all unique and there is no one size fits all so it’s important to do a trial to see how much of each may work for you. This means starting low and increasing until you don’t get added benefits or until you get an adverse effect.
You may do better with a combination of GABA and 5-HTP or you may even find that you do well with one or the other. And you may also find tryptophan works better for you than 5-HTP. We know that 5-HTP can raise cortisol so keep that in mind if you know you have high night-time cortisol. And for many of my clients 250mg to 500mg GABA is too much, although you may be able to get away with more at night than during the day. And different GABA products work well for different people. But again, it’s important to figure out what works for you.
Here are some possible combinations that could help you with the restless nights and anxiety:
- GABA and 5-HTP
- GABA alone
- 5-HTP alone
- Tryptophan alone
- GABA and tryptophan (this is what recommend most of the time)
I recently blogged about the differences between Tryptophan 500mg and Tryptophan Complete (by Lidtke) so the Complete product may well be part of the equation too.
Additional resources when you are new to using tryptophan, 5-HTP, GABA and other amino acids as supplements
As always, I use the symptoms questionnaire to figure out if low serotonin or low GABA or other neurotransmitter imbalances may be an issue.
If you suspect low levels of any of the neurotransmitters and do not yet have my book, The Antianxiety Food Solution – How the Foods You Eat Can Help You Calm Your Anxious Mind, Improve Your Mood, and End Cravings, I highly recommend getting it and reading it before jumping in and using amino acids on your own so you are knowledgeable. And be sure to share it with the practitioner/health team you or your loved one is working with.
There is an entire chapter on the amino acids and they are discussed throughout the book in the sections on gut health, gluten, blood sugar control (this is covered in an entire chapter too), sugar cravings, anxiety and mood issues.
The book doesn’t include product names (per the publisher’s request) so this blog, The Antianxiety Food Solution Amino Acid and Pyroluria Supplements, lists the amino acids that I use with my individual clients and those in my group programs.
If, after reading this blog and my book, you don’t feel comfortable figuring things out on your own (i.e. doing the symptoms questionnaire and respective amino acids trials), a good place to get help is the GABA QuickStart Program (if you have low GABA symptoms). This is a paid online/virtual group program where you get my guidance and community support, and is where this question was asked of me during one of the live Q&A calls.
If you are a practitioner, join us in The Balancing Neurotransmitters: the Fundamentals program. This is also a paid online/virtual program with an opportunity to interact with me and other practitioners who are also using the amino acids.
Wrapping up and your feedback
Keep in mind that low GABA and/or low serotonin are just one of many causes of insomnia. If you try to address what appears to be low levels and it doesn’t work then you have to look for other root causes such as: high cortisol, low blood sugar, SIBO, gluten sensitivity, EMF sensitivity, medication side-effects, caffeine and sugar consumption, benzodiazepine tolerance and/or withdrawal, parasites, and too much light too late or not enough light early in the morning.
Have you used any of the above with good results for sleep? I’d love to hear if you do better with the synergistic effects of two amino acids. And how much works for you?
Or do you do better with another combination?
Feel free to share your feedback and ask your questions below in the comments section.





