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Can Glycine + Amino Acids Be the Secret to Deep, Rejuvenating Sleep?

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With 20 million Americans dealing with occasional sleeplessness that can make life miserable, it’s no surprise many of us are always looking for a better way to get a great night’s sleep.1 A new sleep strategy is now focusing on supplementation with amino acids, with evidence suggesting these compounds may help you fall asleep faster, spend more time in deep sleep, and wake up more refreshed and clear-headed than with conventional sleep formulas.

Considered the building blocks of life, amino acids play many different health-promoting roles in the body, including helping with the formation of neurotransmitters.  These chemical signaling compounds enable nerve-to-nerve communication throughout the brain and nervous system, and are needed to support healthy sleep patterns.

Some neurotransmitters send signals to the brain that help to keep us awake and alert; others regulate the body’s relaxation and mood responses, helping to instill calm, peaceful feelings of drowsiness; and others send the brain signals to fall asleep and stay asleep. Emerging evidence suggests that by targeting these neurotransmitter pathways with amino acid nutrition, we may normalize sleep patterns and promote high-quality sleep that refreshes mind and body.

Amino Sleep: A Novel Sleep Formula Featuring Glycine

Amino Sleep by ProHealth is a groundbreaking nutritional complex that features some of the most widely known sleep-supportive amino acids: Glycine, L-Tryptophan, 5-HTP, and L-Theanine. Let’s take a closer look at how these amino acids, presented in ProHealth’s Amino Sleep, may combine to support rejuvenating rest in a new and different way.

Glycine – 3 g

Helps You Wake Up Clear-Headed & Energized

Glycine is an amino acid that the body produces naturally. In the nervous system, glycine acts as an inhibitory neurotransmitter; this means when it reaches neurons, it calms them so they don’t “fire” with as much electrical activity.2 Glycine is also believed to lower core body temperature and to relax blood vessels at night; both these biological activities have been tied to sleep onset and sleep quality.3

  • In one study, volunteers who complained of sleep problems took either 3 g of glycine or placebo before bedtime and were then evaluated upon waking. In the glycine group, participants reported significant improvements after sleep across fatigue, liveliness, peppiness, and mental clarity.4
  • In another study, ten healthy male volunteers who had no sleep complaints were evaluated for sleep quality spending their usual time in bed, which was an average of 7.3 hours. These participants were then either given a placebo or 3 g of glycine and reduced their time in bed to 5.5 hours for three consecutive nights. At the study’s end, researchers reported glycine was associated with significant improvements in fatigue, daytime sleepiness, and daytime performance after nights where sleep was restricted.5

L-Tryptophan – 100 mg

Accelerates Sleep Onset; Extends Deep Delta-Wave Sleep

Stress and moodiness can wreak havoc on your sleep patterns. The amino acid L-Tryptophan may be perfectly suited to help with these concerns because it promotes a bright mood, relaxed mindset, and restful sleep patterns, all at the same time. L-Tryptophan has been suggested to be important in sleep management because, unlike some synthetic sleep aids, it is not associated with feelings of grogginess and brain fog upon waking.6


Did you know? L-Tryptophan may be especially helpful for women, because research has shown women with low L-Tryptophan levels appear to be more susceptible to mood concerns and relaxation difficulties that can make sleep challenging.7

A portion of the body’s circulating L-Tryptophan is delivered to the central nervous system (CNS), including the brain, where it is used to form neurotransmitters linked to relaxation and mood balance, including serotonin. In the brain, serotonin enhances production of melatonin, an important hormone for supporting normal circadian rhythm and restful sleep. In helping these brain chemicals, L-Tryptophan appears to support sleep:

In one placebo-controlled study of 15 subjects with mild sleep concerns, researchers tested the effects of taking 1 g L-Tryptophan vs. ¼ g of Tryptophan at bedtime. Researchers found that the 1 g dosage accelerated time to fall asleep, while the ¼ g dosage significantly increase the duration of restorative “delta-wave” deep sleep.8

Additional research has suggested that L-Tryptophan appears to help relieve obstructive sleep apnea (but has no effect on central sleep apnea). 9

Griffonia Simplicifolia (98% 5-HTP) – 102 mg

Increases Duration of REM Sleep By 47%

Griffonia Simplicfolia seeds supply 5-hydroxy L-Tryptophan (5-HTP), an amino acid metabolite that the body uses to make the relaxing neurotransmitter serotonin. Serotonin is an important contributor to tranquility and sleep, but is known to decline naturally in the body with age.10 Griffonia’s 5-HTP may help because it is considered to be easy-to-absorb and highly bioavailable, and is also one of the few nutrients that can cross the blood-brain barrier. Here, in the brain, 5-HTP directly influences serotonin and other neurotransmitters associated with mood, relaxation and sleep patterns.

One study, noting that low serotonin levels were associated with sleep problems, investigated how 5-HTP might help. After supplementing 12 healthy volunteers before bedtime, researchers found that 5-HTP appeared to increase duration of REM sleep by up to 47%, leading researchers to draw a correlation between serotonin levels and deep REM sleep.11

L-Theanine – 100mg

Supports Non-Sedating Relaxation Responses

Do you have an excitable personality and racing thoughts that make it hard to “turn off” your brain to fall asleep? L-Theanine in Amino Sleep may be perfect for you. L-Theanine is an amino acid found in green and black tea that may be partially responsible for these beverages’ calming and soothing effects. Like 5-HTP,L-Theanine is capable of crossing the blood barrier and directly influencing brain neurotransmitters, resulting in feelings of relaxation.

  • One research paper proposed that L-Theanine has soothing properties that may initiate high-quality sleep. Notably, researchers point out that L-Theanine does not promote sleep through sedation or drowsiness, but through relaxation. This led researchers to propose L-Theanine as a safe, natural aid for quality sleep without side effects.12

Looking to try a different kind of sleep formula? Supplying multiple evidence-backed amino acids, Amino Sleep by ProHealth offers broad-spectrum neurotransmitter support for deep, restful sleep – minus the grogginess and brain fog that may sometimes accompany some other sleep therapies.


1.    http://www.cdc.gov/sleep/  
2.    http://webspace.ship.edu/cgboer/genpsyneurotransmitters.html
3.    Kawai N, Sakai N, et al.  The Sleep-Promoting and Hypothermic Effects of Glycine are Mediated by NMDA Receptors in the Suprachiasmatic Nucleus, Neuropsychopharmacology, 2015, 40, 6, 1405
4.    INAGAWA, K., HIRAOKA, T., KOHDA, T., YAMADERA, W. and TAKAHASHI, M. (2006), Subjective effects of glycine ingestion before bedtime on sleep quality. Sleep and Biological Rhythms, 4: 75–77. doi: 10.1111/j.1479-8425.2006.00193.x
5.    Bannai M, Kawai N, Ono K, et al. The effects of glycine on subjective daytime performance in partially sleep-restricted healthy volunteers. Front Neurol. 2012;3:61. doi: 10.3389/fneur.2012.00061.
6.    Richard D, Dawes M, et al. L-Tryptophan: Basic Metabolic Functions, Behavioral Research and Therapeutic Indications. International Journal of Tryptophan Research 2009:2.
7.    Bell C., Abrams J., Nutt D. Tryptophan depletion and its implications for psychiatry. British Journal of Psychiatry 2001;178:399-405.
8.    Hartmann E, Spinweber CL. Sleep induced by L-Tryptophan: Effect of dosages within the normal dietary intake. J Nerv Ment Dis. 1979;167(8):497–9.
9.    Schmidt HS. L-Tryptophan in the treatment of impaired respiration in sleep. Bull Eur Physiopathol Respir 19: 625–629, 1983
10.    Payton A, et al. Influence of serotonin transporter gene polymorphisms on cognitive decline and cognitive abilities in a nondemented elderly population. Molecular Psychiatry (2005) 10, 1133–1139. doi:10.1038/sj.mp.4001733; published online 16 August 2005
11.    Wyatt RJ, Zarcone V, Engelman K, Dement WC, Snyder F, Sjoerdsma A. Effects of 5-hydroxytryptophan on the sleep of normal human subjects. Electroencephalogr Clin Neurophysiol. 1971;30:505–9.
12.    Rao TP, Ozeki M, et al. In Search of a Safe Natural Sleep Aid. J Am Coll Nutr. 2015 Mar 11:1-12.

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5 thoughts on “Can Glycine + Amino Acids Be the Secret to Deep, Rejuvenating Sleep?”

  1. AuntTammie says:

    Ok, I was able to go back to the article after making my first comment, and copy the quotes I was referring to. So, here they are:

    “Like 5-HTP,L-Theanine is capable of crossing the blood barrier and directly influencing brain neurotransmitters, resulting in feelings of relaxation and drowsiness.”

    “Notably, researchers point out that L-Theanine does not promote sleep through sedation or drowsiness”

    It would be very helpful if it were possible to still see the article when making a comment.

  2. khealeynj says:

    Excellent article, but I think it would have been wise to add the caveat that if a patient is on an SSRI or SSNRI (as many FM pts. are), one should be aware of the possibility of Serotonin Syndrome, which can be very serious. I experienced this when I tried Tramadol, a non narcotic pain medication, while I was on a low dose (20mg.) of the SSRI Citalopram. Within a few minutes of taking the Tramadol, I couldn’t speak a sentence that made sense, and I stumbled into my bedroom holding onto the walls for support, dropped into bed, fell asleep and woke up 5 hours later. Luckily, I felt fine when I awoke. A few weeks later, curiosity and not having connected the dots yet, made me try a half of a Tramadol– with the same result.
    There are several supplements I would like to try (such as 5 HTP) but as I understand it, they help to produce Serotonin and after my experience with Tramadol which my doctor believes was Serotonin Syndrome, I am leery to try them. I called Pro Health for an opinion on whether my fears were justified before ordering the supplement (and possibly having a more serious reaction this time!), and the answer the young lady gave me was “I have no idea” (and apparently no interest either, because I did not receive any follow up). Obviously, I didn’t take the risk.

  3. LunaNik says:

    The phrase “deep REM sleep” is scientifically inaccurate. During REM sleep, brain waves most resemble those in Stage One, the lightest stage of sleep. Breathing and heart rate increase, blood pressure rises, and dreams occur during REM sleep.

    Stage Four is “deep sleep.” There is no rapid eye movement or muscle activity, and the brain produces only delta waves. Stage Four is also known as “restorative sleep.”

    While increasing REM sleep aids in alleviating depression, and helps improve both learning and memory, increasing delta sleep is required to feel rejuvenated.

  4. Photo1776Bill says:

    Glycine has helped considerably with my long-standing sleep problems (getting asleep, length of sleep, feeling restored). I do occasionally make bone broth, but rely mainly on a glycine powder supplement.

    It is worth reading an article (180degreehealth.com) “Glycine Methionine Balance” by Dr. Joel Brind, a Professor of Biology and Endocrinology at Baruch College of the City University of New York, specializing in amino acid metabolism in recent years, particularly in relation to glycine and one-carbon metabolism.

    “The amino acids glycine and methionine are reciprocal. Specifically, too much dietary methionine depletes glycine, because your body uses up glycine in order to get rid of the excess methionine. This is a common condition these days, because the typical diet is high in methionine-rich muscle meats, but low in glycine-rich bone and connective tissue.

    Methionine—when activated to form S-adenosylmethionine, or SAMe—is the universal methyl donor. As such, it performs the critical function of adding one-carbon methyl groups, an operation necessary to form and modify DNA bases, detoxify drugs, and make certain key molecules like the hormone adrenalin, to name a few examples. Since methionine is so important, the body—mainly the liver—has a number of pathways to reuse, regenerate and recycle methionine. Best known is the methionine cycle, whereby the methyl group—once donated by SAMe—gets added back to the “spent” SAMe (the amino acid homocysteine) to reform methionine. The result of all these pathways is to render the minimal methionine daily dietary requirement very small, i.e., a few hundred milligrams; more like a vitamin than a protein amino acid.

    But the dark side of methionine—long ignored—is that too much is toxic, so that after eating that methionine-rich steak, your liver is not operating the methionine cycle to conserve methionine, but rather, getting rid of it as fast as it can. To do that, the liver needs to use up glycine. Therefore, the more methionine in the diet, the more glycine is needed to help get rid of it.”

    Glycine is a neuro-inhibitor, insufficient amounts may leave neurotransmitters in an excitatory state, thus the sleep problems.

  5. simkatu says:

    As another poster mentioned 5-HTP is a supplement that is known to boost serotonin levels in the brain. Certain anti-depressants known as SSRIs (selective serotonin reuptake inhibitors like Paxil, Zoloft, Prozac and many others) or SNRIs (Serotonin–norepinephrine reuptake inhibitors like Effexor, Cymbalta and many others) also increase serotonin supply in the brain. Too much serotonin can make you very sick and could be very dangerous and could lead to your death if you happen to be operating a motor vehicle when you experience your symptoms. In much of Europe 5-HTP is available only by prescription because of this. 5-HTP is generally safe if you’re not taking other medications, but I think it’s important to let folks know they should discuss taking it with their doctor if they are taking other medication. Their doctor may allow supplementing a drug like Paxil with 5-HTP especially if done in lower steps of 50mg instead of a 200mg pill all at once.

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