8 Best Glycine Supplements (2024) For Restful Sleep, Muscle Recovery, and Cognition (2024)

Glycine is the second most widespread amino acid found in human enzymes and proteins. Although you may not find glycine the most riveting topic, glycine plays a crucial role in everything from sleep to heart health to brain function.

Really, it plays a role in nearly every part of our bodies.

In this article, we’ll go deeper into the research of glycine and amino acids, and give you the top glycine supplement recommendations on the market.

Oh look, a neat little table of contents.

What is Glycine?

Glycine is a non-essential amino acid that helps to make proteins in your body. Non-essential means that our bodies are able to create this amino acid using others rather than needing them from food. These proteins are needed for the growth and preservation of the different tissues in your body and for making hormones and enzymes.

It plays a critical role in your body’s collagen and is found in creatine, both contributing to the structural integrity of your body. As collagen is the most abundant protein in us humans, it’s important to ensure we are getting enough glycine to support muscle growth, an intact GI tract, and slowing down the signs of aging in the skin and joints.

Glycine also produces glutathione, which is an irreplaceable antioxidant in your body that helps fight off diseases, and inflammation and prevents cell damage; so it’s kind of important. Research has shown that the supplementation of glycine in effective doses, shows promise for metabolic disorders in people with cardiovascular disease, diabetes, cancers, and obesity. (1)

In addition to being a component of creating proteins, glycine also has other significant health benefits, most notably for its role insupporting sleep.

The Best Glycine Supplements in 2024

*Note: We do have affiliate links throughout this article, which means we receive a commission if you purchase from any of our links. This supports our mission to bring complicated health and fitness info in an entertaining package. And it keeps us from putting up annoying things like banner ads. Those suck.

Best Glycine Capsules: Slim Sciences Glycine+

Best Glycine Supplement for Sleep: Lifeforce Peak Rest

Best Glycine Powder: Lifeforce Peak Rest

1) Slim Sciences Glycine

8 Best Glycine Supplements (2024) For Restful Sleep, Muscle Recovery, and Cognition (1)

Buy 1 + Get 2 Free


  • Made in an FDA-approved facility
  • 180 money-back guarantee
  • 1000mg of glycine per serving
  • Buy 1 , get 2 free offer


  • None

Slim Sciences Glycine+ checks every box you can look for in a glycine supplement. It is made in anFDA-approved facility in the USA, so it adheres to strict third-party certification.

It’s vegan, non-GMO, allergen-free, soy-free, dairy-free, and gluten-free, so it’s suitable for just about any dietary restrictions.

Every serving comes with 1000mg of glycine.

Third, they’re offering us a Buy 1 Get 2 Free deal right now. There are no strings attached to this. Their single-unit price is a bit pricier than others due to high-quality sourcing and strict testing. But with this deal it’s a great value.

You’re also protected by a 180-day money-back guarantee.They take on all the risk while giving you a great deal.

For all of these reasons, Slim Sciences Glycine+ is our #1 pick.

2) Lifeforce Peak Rest

8 Best Glycine Supplements (2024) For Restful Sleep, Muscle Recovery, and Cognition (2)

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  • 3000mg L-Glycine
  • Comprehensive formula for restful sleep, recovery, stress, and cognition


  • More expensive

This product is completely different from all of the others on this lit but it’s definitely the best one if your goal is restful sleep.That’s because it’s not just glycine, it’s a complete comprehensive formula. The doses and quality of the ingredients in this formula are hard to match.

They include patented key ingredients like CLOCK®, Venetron®, and Zylaria™, and just a pinch of MicroActive® Melatonin. It has3000mg of glycine,200mg of l-theanine, ashwagandha adaptogens for stress support, and creatine monohydrate to help you build and recover.

For sleep and recovery, it’s packed with great ingredients.The only real downside is the cost. Yes, it’s more expensive, but if you struggle with sleep, that’s hard to put a price tag on.

Another key difference is it comes as a powder. The lemon tea flavor is pretty good, and it’s naturally sweetened with stevia. It’s the best glycine powder option if you want a flavored drink.

For its comprehensive formula, Lifeforce Peak Rest is our top glycine supplement for sleep.

3) Double Wood Supplements Glycine

8 Best Glycine Supplements (2024) For Restful Sleep, Muscle Recovery, and Cognition (3)

Check Lowest Price


  • Made in USA
  • 1000mg per serving
  • Great value


  • None

Double Wood Supplements also have a simple, clean, and affordable glycine supplement in capsule form.

This glycine capsule is made in the USA by a family-operated company that prides themselves on quality and authenticity. You get a solid 1000mg per serving of free-form glycine. This is the exact dose used in many studies that show improved sleep quality. Each bottle comes with 300 capsules.

Their glycine capsules are non-GMO, lab-tested, and packaged for quality in the US. This product is also free of any allergens. It’s gluten-free, lactose-free and free from artificial sweeteners, flavors, and preservatives.

They also have a money-back guarantee.

Double Wood also has a great array of single-ingredient supplements, so you stock up on actually the supplement stack you’re looking for.

You also won’t beat the price, especially for the quality.

For all of these reasons,Double Wood Supplements Glycine, is our #2 pick

You can get $15 off purchases of $100 or more at Double Wood with the code, HEALTH 15 and by using this link.

This is a fantastic option if you are looking for an extremely high-quality supplement for an unbeatable price.

4) NOW Foods Glycine

8 Best Glycine Supplements (2024) For Restful Sleep, Muscle Recovery, and Cognition (4)

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NOW Supplements is known for having a huge product list of top-quality supplements at a great price point. Their glycine is no different.

All NOW supplements are made in a GMP-certified facility, which means that every aspect of the manufacturing process has been examined, including the lab testing so you can be guaranteed top quality.

These pharmaceutical-grade glycine capsules are non-GMO, vegan certified, kosher, AND are corn, dairy, egg, soy, gluten, and nut free. Doesn’t get much better than that.

5) PureBulk Glycine

8 Best Glycine Supplements (2024) For Restful Sleep, Muscle Recovery, and Cognition (5)

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This glycine powder is a great alternative if swallowing pills is not your thing. At a bulk price, this is the most economical option.

Each serving is about a ⅓ of a teaspoon which gives you the same amount of glycine (1000mg) as some of our top-rated glycine supplements.

Glycine is tasteless, so thismixes easily into any smoothie, shake, or drink.You can add it to a smoothie, a hydration drink, or really anything at all.

What sets apart PureBulk from other pure glycine powder istheir commitment to quality.Often with companies that go in bulk, you’ll hear about broken sealing, unclear testing certifications, and other problems. With PureBulk and their glycine powder, that’s not the case. Their products are all third-party tested and manufactured in the USA, with the documentation to back it up.

For these reasons PureBulk Glycine is our top choice for the best glycine powder.

6) Life Extension Glycine

8 Best Glycine Supplements (2024) For Restful Sleep, Muscle Recovery, and Cognition (6)

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Per 1 capsule serving of Life Extension’s glycine, you get 1000mg of high-quality, free glycine.

Each bottle gives you 100 capsules. This can give you over three months’ worth of glycine OR you can choose to double/triple up the dosage to maximize the benefits, and still have more than a month’s worth of product.

All in all, a great option and perfect for anyone starting out.

7) Thorne Research Glycine

8 Best Glycine Supplements (2024) For Restful Sleep, Muscle Recovery, and Cognition (7)

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With Thorne, you’ll be paying a premium price, but with that comes premium quality. This glycine supplement is another winner in the Thorne lineup.

Each 2-capsule serving gives you 1g of pure glycine. Although this is on the lower end per serving, you do get 125 servings per bottle so you are definitely getting your money’s worth.

8) Solgar Glycine 500mg8 Best Glycine Supplements (2024) For Restful Sleep, Muscle Recovery, and Cognition (8)

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Solgar’s free-form glycine gives you 500mg per 1 capsule serving.

It’s on the lower end as far as dose, but still a great option. They use a free form of glycine. There’s no confusing evidence that this will make a difference over other forms.

Solgar is a reliable, third-party-certified brand.

How we ranked

Here are some important factors that contributed to products making it on our list.

Quality Testing

The supplement world is littered with tons of products that don’t have any scientific backing to support their ingredients and claims. As such, we’ve only provided you with companies who take pride in quality testing and third-party testing their supplements to ensure top-of-the-line quality. You won’t have to worry that you aren’t getting the best of the best when looking at our rankings.

Effective Dosing

Because you’ll be spending your hard-earned cash on one of these products, we wanted to ensure you were getting every bang for your buck. All the products on this list have effective servings of glycine to ensure you are getting all the benefits from the small but mighty powerhouse that is glycine.

Clean formulations

Purity is extremely important when picking a supplement. We wanted to be sure that every product on this list could pass any purity test out there and is free of any common allergens.

Single Ingredient Supplements

There are lots of expensive sleep supplements out there that contain glycine. However, if you want its benefits for the best price, single-ingredient supplements are the way to go.

With that said, the exception on our list is Lifeforce Peak Rest. Yes, it’s a bit expensive, butit’s hard to put a price on getting quality sleep. It’s a product that willdefinitely help you do that.

The Benefits of Glycine

Required to Make a Powerful Antioxidant

Glycine is one of 3 amino acids our body uses to create the very important glutathione. This extremely powerful antioxidant works to protect our cells against oxidative damage from free radicals. These are thought to be underlying issues with many diseases like cardiovascular disease, cancer, muscle loss (sarcopenia), chronic kidney disease, and more. (2)

Especially as we get older, our body’s natural glutathione levels decrease, which makes glycine even more important to ensure you are protecting yourself against cell damage. If your goal longevity, look into supplementing with NAC as well, which also helps produce more glutathione.

(Or, consider supplementing with glutathione. Learn more at this article on glutathione supplements.)

Fights Fatigue and Supports Restful Sleep

8 Best Glycine Supplements (2024) For Restful Sleep, Muscle Recovery, and Cognition (9)

Sleep, or lack thereof, is a rising epidemic in our modern world. Although you may feel ok to function, consistently not getting enough sleep wreaks havoc on just about everything in your life. Sleep depreviation plummets your cognitive function, metabolic function, and nearly every health marker you can think of. While there are many ways you can improve your sleep quality, glycine could also lend a helping hand.

Glycine has a natural ability to lower your core body temperature, which in addition to its calming effects on the brain, can help you fall asleep faster and stay asleep. (3) In fact, we’ve written a whole article about how glycine may support sleep.

Research in people who have been consistently struggling with not getting good sleep showed that taking 3 grams of glycine as a dietary supplement before bed allowed the participants to have improved overall sleep (both time sleeping and quality), have less daytime sleepiness, and improve performance of memory recognition tasks. (4)

Building Block to Creatine and Collagen

Just like its role in creating glutathione, glycine is also one of three amino acids our bodies use to make creatine. It’s then pushed into our muscles to give them more energy, increased recovery, and better performance.

Creatine is one of the most studied and researched supplements on the market. Through all that research, it’s been proven that in combination with resistance training, supplementing with creatine helps increase overall muscle strength, power, and size. (5)

Glycine is also a major component of collagen, which is the most abundant protein in the body. Because collagen plays such an integral role in the health of your hair, skin, nails, joints, and bones, getting enough glycine is important to help support the body’s natural production of collagen. In fact, glycine is often an added ingredient to the best collagen supplements.

Supports the Nervous System and Cognition

Glycine acts as a neurotransmitter in the central nervous system (CNS). It helps process motor and sensory information that allows movement, vision, and hearing. (6, 7)

It also acts as an inhibitory neurotransmitter in our brain that promotes serotonin levels and increases relaxation. One study even found that glycine decreased anxiety related to work performance while reducing the feeling of fatigue felt throughout the day. (8) This research also showed that the participants who did take glycine, also had better energy and memory for the duration of the day.

These benefits reach past improving fatigue and brain health. Glycine has also been studied to help with depression and even other significant mental health diseases like schizophrenia. A study with 21 schizophrenic patients showed that there was a 34% reduction in negative symptoms during the high-dose glycine treatment. (9) These brain-boosting benefits could also apply to other mood, and neurodegenerative disorders, like Alzheimer’s. This study suggests that glycine is a safe therapeutic option that could be used for age-related neurodegenerative diseases. (10)

May Support Heart Health and Metabolic Health

Glycine plays a role in lowering blood pressure, insulin, and blood sugar. But studies have also found that high levels of circulating glycine have been associated with lower levels of heart attacks and type 2 diabetes. Another study indicated that glycine is genetically associated with a lower risk of heart disease and that this could be studied by the blood pressure-lowering effect that glycine has on the cardiovascular system. (11)

If you haven’t already bought the first glycine supplement to cross your screen after reading all those benefits, here is a list of the top glycine supplements currently on the market.


Should I take glycine in the morning or at night?

The short answer is anytime. If you are looking to use glycine to improve sleep quality then take it at night. But if you are for example looking to support your insulin production throughout the day, it’s best to take it in the morning.

Bottom line, if you are looking to get restorative or sleep benefits (which are 90% of the benefits) from the glycine try it before bed. If you are looking for insulin support, try taking it in the morning.

What foods naturally have glycine?

Bone broth will be your best bet if you are looking for a one-and-done solution. It will have the highest amount of glycine per serving and is also delicious.

If you don’t like or don’t have access to bone broth, you can also find glycine in complete sources of protein such as red meat, dairy products, poultry, eggs, and fish. If you are looking to stay away from animal products, beans, lentils, nuts, and seeds also contain glycine.

Here’s a quick list:

  • Bone broth
  • The skin of chicken and turkey
  • Seafood
  • Beef
  • Legumes (such as soybeans and tofu, peanuts and peanut butter, peas, mungo beans, lentils, and kidney beans)
  • Spinach, although you’d have to eat a lot

If you have a high-protein diet, there’s a good chance you’re getting your fix of glycine.

Will glycine help me sleep better?

Yes. Taking glycine before bed can help your body get to sleep faster, stay asleep longer, and allow you to wake up feeling fully rested.

Research has also shown that supplementing with glycine elevates serotonin, the happy hormone which is required to make the sleeping hormone melatonin, and reduces the symptoms of insomnia.

In addition to this, glycine also plays a role in lowering your core temperature while you sleep which again plays into better sleep quality. Studies have shown it to also help in getting people back on a regular sleeping schedule and sleep cycles which will further the benefits of sleep and feeling rested.

Are there side effects of glycine supplementation?

You could experience some gastrointestinal issues if you are sensitive to starting new supplements.

In that case, simply lower the dose and work your way up to the recommended dose on the bottle. You can also split your dose between morning and evening, and take it with meals.

What is the best form of glycine?

L-glycine is the go-to form. It’s the default choice and the one you’ll most commonly find in supplements.

How much glycine should I take a day?

The amount of glycine you should take can vary based on your individual needs and goals. For sleep, most of the research shows effectiveness at around 3-5 grams.

Is glycine or GABA better for sleep?

Glycine has been shown to support restful sleep, but comparing it to GABA is like comparing apples to oranges. Both have their unique benefits, and the best choice depends on your specific needs.

For more on GABA check out our article on the best GABA supplements.

Can I take glycine if I have a stomach ulcer?

Stomach ulcers are serious. While glycine is generally safe, it’s best to consult with a healthcare provider if you have a stomach ulcer or any other medical condition.

Is glycine a good supplement for weight loss?

Glycine is not a weight loss supplement. It’s got a lot of powers, but melting away those pounds isn’t one of them. If weight loss is your goal, focus on a balanced diet, regular exercise, and maybe a high-five (or training session) from a fitness professional.

Does glycine support healthy glucose levels?

Yes, glycine has been shown to play a role in supporting healthy glucose levels. It’s involved in the production of several key enzymes that help regulate glucose metabolism. However, it’s essential to note that glycine is not a magic bullet for glucose control. It can be a supportive player in a broader strategy that includes a balanced diet, regular exercise, and appropriate medical care.

Does glycine encourage protein synthesis?

Glycine is an amino acid, so it can support protein synthesis. However, it won’t be as effective for this as the branched-chain amino acids.

How long does it take for glycine to work?

For sleep, glycine can have benefits right from the very first night.

Will glycine help with my anxiety?

Glycine’s not designed to treat anxiety, so don’t go ditching your medications. That’s a terrible, terrible idea without guidance from your healthcare provider.

Is it safe to take glycine every night?

Yes, glycine is considered safe to take every night. But, as with all things supplement-related, it’s wise to check in with a healthcare provider to make sure it’s the right move for you.

Glycine can be an effective piece of a nightly supplement stack. You won’t build a tolerance to it like other sleep supplements, like melatonin.

What time should I take a glycine supplement?

If you’re taking glycine for sleep support, then nighttime is your prime time. As a rule of thumb, take about 30-90 minutes before bed. Consult with a healthcare provider for personalized guidance.

Does glycine support skin health?

Glycine is also often a component of skin and hair supplements. t’s a key component of collagen, which is vital for maintaining the elasticity and strength of your skin. By supporting collagen production, glycine may help keep your skin looking youthful and vibrant. For the same reasons it may support your connective tissues like joints and tendons. However there isn’t much research on glycine supplementation to support its benefits specifically for skin health.

Because of this, glycine can sometimes be cleverly marketed as an anti-aging supplement, but there isn’t evidence to back up this claim.

How do I know if my glycine levels are low?

If you’re wondering if your glycine levels are low, you can talk to your healthcare provider about getting a plasma glycine test. If you take glycine consistently at the recommended doses for several weeks and see no benefit, it may be because you have sufficient glycine levels.

What other supplements may support sleep?

Some include…

  • Magnesium
  • N-acetyl-cysteine (NAC)
  • L-theanine

Who should NOT take a glycine supplement? Are there side effects to taking glycine?

Everybody should talk to their healthcare provider before taking a supplement. In particular, if you’re pregnant or breastfeeding you should stay away from glycine supplements.

It may also interact with certain medications, so again, talk to your healthcare providers. We are not doctors, and we don’t pretend to be them on the internet.

About the Author

Stephanie is a fitness coach and lifelong learner of all things health and fitness. She graduated with her honors specialization in Kinesiology and has worked with hundreds of individuals to reach their physique goals. In her free time, you can catch her on the hiking trails or with her puppy Zoe.

Comments for This Entry

  • 10 Best NAC Supplements (2022) Reviewed and Compared

    […] Glycine also plays a “building block” role in glutathione production. It also has an array of other benefits like improving sleep quality. You can learn more about glycine at this article on the best glycine supplements. […]

    December 1, 2022 at 9:50 am

8 Best Glycine Supplements (2024) For Restful Sleep, Muscle Recovery, and Cognition (2024)
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