What Glycine can do for Sleep


Too wound up at night to fall asleep easily? Glycine has a calming action and a slightly sedative effect. This works well when you need to relax. It helps switch off the thoughts that keep running through your head and keep you awake long after you go to bed. Here is what it does for your sleep, and how to take it.

What it is

Glycine is the smallest and simplest of all amino acids. Don’t let that fool you. Your body needs it to work properly. It’s essential for muscle, cognitive and metabolic functions. But it also serves as a neurotransmitter. And as an “inhibitory” neurotransmitter, glycine promotes restful sleep. Not only that, it has a lot of other impressive benefits.

What Glycine can do for Sleep

Research shows that:

  • Taking glycine before sleep improves sleep quality
  • It also improves sleep efficacy by decreasing time to fall asleep
  • It increases slow wave deep sleep
  • After taking glycine, people had less daytime sleepiness and improved performance on memory recognition tasks the following day
  • Glycine helps improve REM sleep and decrease non-REM sleep
  • 3g of Glycine given to volunteers before going to sleep showed improvements in fatigue, ‘liveliness and peppiness’, and ‘clear-headedness’
  • Glycine helps improve daytime sleepiness and fatigue induced by sleep deprivation (if you suffer from sleep deprivation, taking a nap can make all the difference)
  • It affects certain neuropeptides in the region of the hippocampus which regulate the circadian rhythm
  • Glycine increases vasoactive intestinal peptide (a peptide hormone) which is critical in driving the circadian rhythm

what glycine can do for sleepBenefits of Glycine

  • has anti stress actions
  • is anti- inflammatory
  • improves skin elasticity and moisture retention
  • it’s good for your gut
  • shows positive impact on mental illnesses
  • improves depressive symptoms
  • can help with weight loss
  • restores glutathione synthesis
  • helps with diabetes and metabolic disorders
  • can lower blood pressure
  • helps with joint and muscle aches
  • protects against arthritis
  • protects the liver
  • slows alcohol absorption
  • reduces tooth cavities

Why your body needs it

Glycine is non-essential, meaning it is so important that your liver can make some if your dietary intake is inadequate. But it can’t make an unlimited amount. And the typical diet usually comes up short, sometimes by as much as 8-10 grams of glycine per day.

Glycine has many critical functions in the body, some of which were only recently discovered. Essential to your health is the fact that glycine is the most important endogenous regulator of inflammation*  Eating too much methionine (for example in red muscle meats) uses up glycine, potentially causing a deficiency.

Glycine also benefits the immune system. It’s main physiological function is to regulate the macrophages (large white blood cells) so they can go about their business of cleaning up after any injury.

Try that one out:

If you get sore after vigorous exercise, supplement with glycine before your next hard workout. The body will respond to the damage caused to the muscles by building even more muscle fibers, but the soreness is actually due to inflammation. Because of glycine’s anti inflammatory actions, the soreness doesn’t happen when you take it prior to exercise.

*(Glycine appears to exert several protective effects, including anti-inflammatory, immunomodulatory and direct cytoprotective actions. Glycine acts on inflammatory cells such as macrophages to suppress activation of transcription factors and the formation of free radicals and inflammatory cytokines.” – Pubmed 12589194

What’s the right dosage and when do I take it?

Joel Brind, PhD, Professor of Biology and Endocrinology at Baruch College of the City University of New York recommends 8 grams per day. Watch his video lecture on the anti inflammatory properties of glycine.

Other experts recommend 3 – 5g a day.

To help with a restful night’s sleep, it is best taken before bedtime. To avoid soreness after a vigorous workout, take some before exercise.

Natural Sources of Glycine

Top source: Gelatine.

An easy way to get additional glycine is to take gelatine. Gelatine is made up of 35% glycine, 11% alanine, and 21% proline and hydroxyproline.

Some types of cell damage are prevented almost as well by alanine and proline as by glycine. So the use of gelatin rather than glycine on it’s own, is preferable, because in gelatin the glycine is associated with its naturally occurring biochemicals.

To make a calming nightcup, stir a tablespoon of plain gelatine into a hot cup of tea (preferably not caffeinated). It won’t affect the taste.

Other sources: pig skin and ears and tails, and chicken feet (commonly found in Asian grocery stores). If that doesn’t excite you much, stick with gelatine.

Here are a couple of options from Amazon:

Zint Beef Gelatin

Great Lakes Gelatin 

Possible Side Effects

Slight sedation can be a side effect of taking glycine. That’s why it’s best to take in the evening if you’re after the calming effect that helps you fall sleep. Even better, not only does it help you fall asleep more easily, it also helps you function better on less sleep.

It is generally considered non toxic.


Pure glycine is a useful and remarkably safe drug. But don’t think of it as a food because it is a manufactured product.

If you would like to supplement with glycine, try these:

Other Interesting Actions of Glycine

  • The nervous system uses glycine as an inhibitory neurotransmitter. This makes it important to help prevent epileptic seizures
  • It is also used in the treatment of manic depression and hyperactivity
  • Glycine is part of the major energy producing biochemical processes in the body
  • It is also found in prostate fluid in males and is important for normal prostrate functioning
  • Glycine has an important antioxidant action
  • It is necessary for central nervous system function
  • Glycine increases the biosynthesis of glutathione (a major anti-oxidant produced by the body)
  • It inhibits lipolysis – this makes insulin more effective and helps to prevent hyperglycemia
  • Glycine facilitates the action of insulin in lowering blood sugar and alleviating diabetes

Further reading on the importance of glycine:

Ray Peat on Glycine















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