Quick answer
Glycine is a simple amino acid that has been studied as part of evening routines. In a 2007 study, people who took 3 grams of glycine before bed reported better subjective sleep quality and less daytime sleepiness than with placebo. The research is small, so glycine is best seen as one option to discuss alongside good sleep habits.
Key takeaways
Glycine is the smallest amino acid, and your body makes it as well as getting it from protein-rich foods.
A small study found people who took glycine before bed reported better sleep quality and less daytime sleepiness, though the research is still limited.
Glycine is best seen as one possible addition to an evening routine that already includes steady sleep habits.
Glycine is less well known than magnesium or melatonin, but it comes up more and more in conversations about sleep. Here is what it is and what the research has looked at.
What is glycine?
Glycine is the smallest amino acid. Your body makes it, and it is found in protein-rich foods, especially collagen and bone broth. As a supplement it usually comes as a powder with a mildly sweet taste.
What does the research say about glycine and sleep?
In a 2007 study from Japan, volunteers who had concerns about their sleep took 3 grams of glycine or a placebo before bed. With glycine, they reported better sleep quality, and sleep recordings showed they reached deep sleep sooner. They also reported feeling less fatigued the next day.
This was a small study, so larger trials are still needed.
How do people usually take glycine?
Studies have used about 3 grams taken shortly before bed, often stirred into water or tea. Always follow the label on your product, and check with your provider first if you take medications for mood or sleep or have a health condition.
Where can I find a quality glycine powder?
You can find practitioner-grade options in my Fullscript store, which offers professional brands with strong quality standards. Glycine is sometimes paired with magnesium glycinate in evening routines.
Looking for a quality option from a professional brand? My Fullscript store has you covered.
Questions to bring to your clinician
These questions can help you get the most out of your next visit.
Could glycine fit into my evening routine alongside my current sleep habits?
Is glycine a reasonable choice alongside my current medications and supplements?
Would it be worth checking any labs before I try glycine, or is my history enough to decide?
What would tell us that glycine is working well for me, and how long should we wait before reviewing it?
Practitioner-grade options in my Fullscript catalog: if you and your clinician decide a supplement makes sense, my supplement guide by health goal links to the practitioner-grade products I trust.
Frequently asked questions
Does glycine help you sleep?
A small 2007 study found that 3 grams of glycine before bed was linked to better subjective sleep quality compared with placebo.
How much glycine is used for sleep?
The study used 3 grams taken shortly before bed. Follow the label on your product.
Can I take glycine with magnesium?
Many evening routines combine them. Check with your provider if you take medications.
Sources
- Yamadera W, et al. Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes. Sleep Biol Rhythms. 2007. https://doi.org/10.1111/j.1479-8425.2007.00262.x
Prefer to talk it through? A free 15-minute intro call is a simple place to start.
This page shares general educational information and is not medical advice. These statements have not been evaluated by the Food and Drug Administration. Talk with your healthcare provider before starting a supplement, especially if you take medications, are pregnant or nursing, or have a health condition.
Looking for practitioner-grade options?
The catalog carries third-party-tested, practitioner-grade supplements from brands Dr. Kneessi uses in practice.
See practitioner-grade options in the catalogNot sure what fits? Take the Supplement Quiz →Free: The 28-Day Reset for Energy and Focus
A simple day-by-day email guide to sleep, movement, food, and daily habits that support healthy aging. It’s free, and you can unsubscribe anytime.
Get the free guide Take the supplement quiz
