The Elusive Full Night’s Rest

Could a deficiency of the amino acid glycine prevent healthy sleep?

Could a deficiency of the amino acid glycine prevent healthy sleep?  

Got sleep? It seems that many of us are having trouble getting enough of it these days. In fact, the Centers for Disease Control (CDC) acknowledged that sleep deprivation is a serious health concern leading to other health problems, such as obesity, depression, and diabetes. More than a quarter of Americans report occasional trouble sleeping and up to 10 percent have chronic insomnia.1 While many of us could blame stress or any number of other reasons why we have trouble falling or staying asleep, one reason that has been generally overlooked is a deficiency in the amino acid glycine.

New research indicates that a lack of glycine in the diet may contribute to difficulty sleeping and initial studies are showing that people supplementing with glycine fall asleep sooner and experience deeper sleep while actually feeling more alert the following day.4

Glycine can act in several ways to support sleep. One study showed that oral glycine increased serotonin in rats; serotonin is then converted to melatonin, the “sleep” hormone. 2 Glycine, along with GABA, also acts on the central nervous system by inhibiting the skeletal muscles during sleep, allowing us to dream and experience REM sleep without moving about in our beds.3

Several researchers believe that the primary effect that glycine may have on sleep physiology is how it helps maintain a lower core body temperature during sleep.5 During healthy sleep the body’s temperature naturally decreases during the course of the night, and if for some reason this core temperature rises, it can cause us to wake. Have you ever noticed waking up and feeling hot?

So why might you be deficient in glycine? One of glycine’s primary jobs is to manufacture connective tissue, including collagen. The body makes three grams a day but needs about 15 grams daily to rebuild collagen and other tissues. Traditionally dietary glycine comes from food sources like collagen found in the bones, joints, and skin of animal products—foods that are not readily consumed in our modern diet. So, if you are not eating chitlins, cracklins, and gizzards regularly and/or making homemade bone broth, you may want to consider supplementing with glycine. How much you ask? One study used three grams of pure glycine before bedtime. Jonathan Wright, MD, medical director of the Tahoma Clinic in Washington, suggests aiming for ten grams a day to restore glycine levels in the body. His favorite way to take it is by mixing glycine powder with a purified gelatin and some healthy flavorings (chocolate, fruit, etc.) to make a dessert pudding. He recommends gelatin since it also contains a high amount of glycine (approximately 30%) along with a balance of other naturally occurring amino acids.

As many of us struggle with getting enough sleep, it is nice to know that there is an additional tool that we can use to unlock the mystery of a restful night’s sleep.1


A Word of Caution Regarding Glycine and Cancer

Cancer patients with active tumors should exercise caution in using glycine. Research indicates that certain cancer cells may proliferate rapidly by preferentially utilizing glycine as an energy source. Please work closely with your doctor if you have or have had cancer before supplementing with glycine.


Created 10/13



  1. ; sourced 7/19/2013
  2. Bannai, et al; Oral administration of glycine increases extracellular serotonin but not dopamine in the prefrontal cortex of rats; Psychiatry and Clinical Neurosciences; Volume 65, Issue 2, pages 142–149, March 2011
  3. Brooks and Peever; Identification of the Transmitter and Receptor Mechanisms Responsible for REM Sleep Paralysis; The Journal of Neuroscience, 18 July 2012, 32(29): 9785-9795
  4. Yamadera, et al; Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes; Sleep and Biological Rhythms; Volume 5, Issue 2, pages 126–131, April 2007
  5. Bannai and Kawai; New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep.; J Pharmacol Sci. 2012;118(2):145-8. Epub 2012 Jan 27.
  6. Jonothan V. Wright; This 50¢ a day anti-aging supplement could have you turning back the hands of time starting today–and sleeping like a baby tonight; Nutrition and Healing; Vol. 19 Issue 12
  7. Jain, et al.; Metabolite Profiling Identifies a Key Role for Glycine in Rapid Cancer Cell Proliferation; Science 25 May 2012: Vol. 336 No. 6084 pp. 1040-1044.