7 Best Glycine Supplements (2023) Reviewed and Compared

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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.

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.

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 is support 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

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 procees 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.

*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.

1) Double Wood Supplements Glycine

Double Wood Supplements Glycine

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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 3000mg 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 #1 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.

2) NOW Foods Glycine

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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.

3) PureBulk Glycine

PureBulk Glycine

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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 this mixes easily into any smoothie, shake, or drink. You can add it to a smoothie, a hydration drink, or really anything it all.

4) Life Extension Glycine

Life Extension Glycine

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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.

5) Pure Encapsulations Glycine

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Pure encapsulations deliver a simple, yet effective glycine supplement to add to their growing list of top-performing products. Per 3-capsule serving, you get a slightly lower dose of 1500mg. However, you do get 60 servings per bottle.

Quality is not something you have to worry about with this brand as it’s free from any GMOs, binders, fillers, preservatives, gluten, and common allergens. These are on the pricier side, so if you have some extra cash hanging around, this could be a great option.

6) Thorne Research Glycine

Thorne Research Glycine

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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.


7) Solgar Glycine 500mgSolgar glycine 500mg

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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.

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.


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.

Foods that 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.

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 lower 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 to taking glycine?

There are no real side effects to taking glycine. You could possibly 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.

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 yo 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.

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