Ingredient Spotlight! Glycine for Sleep
glycine is the amino acid that makes up nearly half of every dose in our Sleep Manager. In plain terms, glycine is both a building block in proteins and a calming neurotransmitter, which is why it is a popular ingredient in sleep formulas. Below is what it does, how it works, and the practical dose used in the research.
An interesting point about glycine is that it is already the main component of collagen, making up about 30% of the amino acids. This glycine factor is responsible for much of the anti-inflammatory action of collagen hydrolysate because it can make certain white blood cells less reactive. Since we started selling collagen way back in the early 2000’s, we have also heard consistent feedback that some people sleep better when taking collagen. When we looked into it, the simplest explanation was that collagen delivers extra glycine.
As well as being anti-inflammatory, glycine is an inhibitory neurotransmitter that can be found throughout the central nervous system. Its impact on sleep is well studied, both as regards the mechanisms of action and the effectiveness of taking it as a supplement. What have they found?
Glycine helps you feel like you slept well
A 2007 placebo-controlled trial[1] involving ingestion of 3g of glycine (this is the amount in Sleep Manager) at bedtime suggests that this dose both promotes and stabilises sleep and leads to subjective feelings of having slept well. Participants also felt more awake the next day and performed better on memory recognition tasks than placebo. In another study, people that had restricted sleep time reported feeling mentally sharper and less fatigued after pre-sleep glycine ingestion[2].
Glycine enhances natural sleep processes
A key feature of natural sleep initiation is a lowering of core body temperature. Human and animal trials show that glycine lowers core body temperature in a similar way to some sleep pharmaceuticals by interacting with receptors in the brain region known as the suprachiasmatic nucleus (SCN) [3]. Animal studies suggest that other mechanisms of action for glycine include modulation of the orexin (wakefulness) neurons and increased serotonin in the prefrontal cortex[4] which can lead to increased production of melatonin (the 'sleep hormone').
Sleep Manager contains an efficacious dose of 3 grams high quality glycine: 600mg from collagen and 2400 from glycine as an added amino acid. We’ve then added a bunch of other sleep supporting amino acids along with vitamins and minerals to ensure that we’re giving you the best shot at a great night’s rest.
Other sleep articles from the Puraz Blog:
Top Ten Tips for a Better Night's Sleep
What Sleep Deprivation Really Does to You
References
- Sleep and Biological Rhythms 2007; 5: 126–131
- Front Neurol. 2012; 3: 61.
- Neuropsychopharmacology.2015 May;40(6):1405-16
- Psychiatry Clin Neurosci.2011 Mar;65(2):142-9
FAQ
What is glycine and how can it support sleep?
Glycine is an amino acid that also acts as an inhibitory neurotransmitter in the central nervous system. Taken before bed, it can support sleep quality and next day alertness by helping your body shift into its normal sleep mode. For many people, a simple starting point is a low dose first, then working up to the studied 3g if it suits you.
How much glycine is used in sleep studies?
Many human trials use 3g of glycine taken at bedtime. That is the same total dose used in our Sleep Manager formula. If you are sensitive to supplements, start smaller and increase gradually.
How does glycine help you feel like you slept well?
In a placebo-controlled trial, people who took glycine at bedtime reported better subjective sleep quality. They also felt more awake the next day and did better on memory recognition tasks than placebo. If your sleep is occasionally short, glycine may still help you feel less fatigued the next day.
Does glycine change core body temperature?
A key part of falling asleep naturally is a small drop in core body temperature. Human and animal research suggests glycine can support that cooling effect by acting on receptors linked to the brain clock system. Practically, take it near bedtime and keep your sleep environment cool for the best odds of noticing the effect.
Can you take glycine with collagen?
Yes, collagen already contains a meaningful amount of glycine, which is one reason some people report better sleep when using collagen. In Sleep Manager, part of the 3g dose comes from collagen and the rest from added glycine. If you already use collagen at night, check your total glycine intake across products.
How long before bed should you take glycine?
Most people take glycine shortly before getting into bed. That timing aligns with how it can support the normal temperature drop and wind-down phase. If you are experimenting, try a consistent time for a week so you can judge the difference.
Is glycine safe for everyone?
Glycine is a common amino acid found in food, but individual responses can vary. If you are pregnant, breastfeeding, managing a medical condition, or taking medication, it is sensible to check with a clinician before adding any sleep supplement. If you notice vivid dreams, stomach upset, or morning heaviness, reduce the dose or stop.