If you are looking for the best glycine supplement, start with the label. The dose, serving size, capsule count, testing standards, and ingredient list can tell you a lot.

Glycine is an amino acid involved in protein production, collagen formation, nervous system signaling, and glutathione production. Many people use glycine supplements for sleep, relaxation, recovery, and general wellness support.

In this review, we compare the best glycine supplements in 2026 by dose, formula type, quality standards, ease of use, and who each product is best for.

Quick Verdict: What Is the Best Glycine Supplement?

The best glycine supplement for most people is Omre Glycine + NAC because it combines 1,000 mg of glycine with 500 mg of NAC in one simple daily formula.

This makes it a strong fit for people who want more than plain glycine. Glycine may support relaxation and sleep quality, while NAC helps support the body's production of glutathione, a major antioxidant compound involved in cellular defense.

If you only want plain glycine at a low cost, Nutricost L-Glycine is the better budget pick. If you want a larger bottle for long-term use, Double Wood Supplements Glycine makes sense.

If you want a 3,000 mg sleep-focused amount, NOW Foods Glycine gives you more dosing flexibility because it provides 1,000 mg per capsule and suggests 1 to 3 capsules daily.

Best Glycine Supplements: Our Top Picks

• Best Overall: Omre Glycine + NAC
• Best Budget: Nutricost L-Glycine
• Best Value Size: Double Wood Supplements Glycine
• Best Clean Label: Pure Encapsulations Glycine
• Best Higher Dose: NOW Foods Glycine
• Best Research Focused: Life Extension Glycine

Top Glycine Supplements Compared

Product	Category	Glycine Per Serving	Added Ingredients	Best For
Omre Glycine + NAC	Best Overall	1,000 mg glycine + 500 mg NAC	NAC	Sleep support plus antioxidant and cellular health support
Nutricost L-Glycine	Best Budget	1,000 mg	None	Simple, low-cost glycine capsules
Double Wood Supplements Glycine	Best Value Size	1,000 mg	None	Long-term daily use
Pure Encapsulations Glycine	Best Clean Label	1,500 mg	None	Sensitive users and clean-label shoppers
NOW Foods Glycine	Best Higher Dose	1,000 mg per capsule, suggested use allows 1 to 3 capsules daily	None	Flexible dosing up to 3,000 mg daily
Life Extension Glycine	Best Research Focused	1,000 mg	None	Research-led supplement users

How We Chose the Best Glycine Supplements

We looked for glycine supplements that are practical, clearly labeled, and easy to use consistently. Since many people take glycine at night, we paid close attention to serving size, capsule count, ingredient quality, and testing standards.

Clear Glycine Dose

A good glycine supplement should clearly state how much glycine you get per serving. Most products on this list provide between 1,000 mg and 3,000 mg.

This matters because some readers want a simple 1,000 mg daily routine, while others want to get closer to the 3,000 mg amount used in some sleep-focused clinical studies.

Practical Serving Size

A supplement can look strong on the front label, but the Supplement Facts panel tells the real story.

We looked at:

• Glycine amount per serving
• Capsules per serving
• How many servings are in the bottle
• Ease of taking the product at night
• Whether the dose makes sense for daily use

A 3,000 mg dose can be useful for some people, but it may also mean taking several capsules. That is not a deal-breaker. It just needs to be clear.

Testing and Quality Standards

We gave stronger consideration to brands that mention third-party testing, GMP manufacturing, certificates of analysis, heavy metal testing, or clear quality control standards.

For amino acid supplements, this matters. You want the label to match what is inside the bottle, and you want basic contaminant testing for things like heavy metals and microbes.

Simple Ingredient Lists

Some people want glycine alone. Others may prefer a formula with added support, such as NAC.

We included both styles so readers can choose based on their own goals. Plain glycine is better for people who want a single-ingredient amino acid. Glycine plus NAC may suit readers who want glutathione support and antioxidant balance in the same formula.

Ease of Daily Use

Capsules are simple, taste-free, and easy to add to a bedtime routine. That matters because the best supplement is the one you can take without turning your nightstand into a science lab.

Powder can make sense for higher doses, but capsules win for convenience.

Best Urolithin A Supplements Reviewed

1. Best Overall: Omre Glycine + NAC

Best for: People who want glycine plus NAC in one formula, rather than buying two separate supplements.

Omre Glycine + NAC is our best overall pick because it gives you more than a basic glycine capsule. Each serving provides 1,000 mg of glycine, paired with 500 mg of NAC.

Glycine may support relaxation and sleep quality. NAC, short for N-acetyl cysteine, is commonly used to support glutathione production. Glutathione is one of the body's main antioxidant compounds, and it plays a role in cellular defense and oxidative stress balance.

That pairing is the main reason Omre stands out. Many glycine supplements only focus on sleep. Omre Glycine + NAC fits better for people who want sleep support, antioxidant support, and cellular health support in one simple formula.

This does not mean glycine plus NAC is a magic shortcut. It means the ingredient pairing has a clear reason behind it. Glycine and cysteine, supplied by NAC, are both used by the body to make glutathione.

Omre Glycine + NAC is also a good fit for readers who care about clean formulation. The product is made in the USA in GMP-compliant facilities, uses vegetarian capsules, and is free from common allergens.

For people comparing the best glycine supplements in 2026, Omre is the strongest all-around choice because it covers more than one goal without becoming a crowded proprietary blend.

Pros:

• Combines 1,000 mg glycine with 500 mg NAC.
• Supports sleep, relaxation, antioxidant balance, and cellular health.
• Strong choice for people interested in GlyNAC-style support.
• Vegetarian capsules.
• Free from common allergens.
• Made in the USA in GMP-compliant facilities.

Cons:

• Not a single-ingredient glycine supplement.
• May not suit people who only want plain L-glycine.
• People sensitive to NAC should speak with a healthcare professional first.

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2. Best Budget: Nutricost L-Glycine

Best for: People who want affordable, single-ingredient glycine capsules.

Nutricost L-Glycine is a good budget pick for people who want a simple glycine supplement without paying for added ingredients. Each capsule provides 1,000 mg of glycine, which is a common starting amount for sleep and relaxation support.

This formula does not try to be fancy. That is part of the appeal. You get L-glycine in a straightforward capsule format, which makes it easy to add to a nighttime routine.

Nutricost also makes sense for beginners. If you are new to glycine and want to see how your body responds, a 1,000 mg capsule is easier to work with than jumping straight into a higher dose.

The downside is that this is plain glycine only. There is no NAC, no magnesium, no herbal blend, and no added sleep ingredients. For many readers, that is fine. For others, especially those looking for antioxidant or cellular health support, Omre may be the better fit.

Pros:

• Provides 1,000 mg glycine per capsule.
• Affordable and simple.
• Good starter option.
• Vegetarian, non-GMO, and gluten-free.
• Third-party tested.

Cons:

• No added NAC or broader antioxidant support.
• Lower dose than the 3,000 mg amount used in some sleep-focused studies.
• May require multiple capsules for higher-dose routines.

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3. Best Value Size: Double Wood Supplements Glycine

Best for: People who already know glycine fits their routine and want a larger daily-use bottle.

Double Wood Supplements Glycine is a strong value pick for people who plan to take glycine consistently. Each serving provides 1,000 mg of glycine, which keeps the dose easy to understand and easy to repeat.

This is another single-ingredient glycine supplement. It does not include NAC or extra sleep ingredients. That makes it a clean choice for readers who want to control their supplement stack and keep each ingredient separate.

Double Wood also highlights testing for microbes and heavy metals. That is a useful trust signal, especially for people who compare supplement quality closely.

The main limitation is dose flexibility. A 1,000 mg capsule works well for a simple routine, but someone targeting 3,000 mg before bed would need multiple capsules. If that sounds annoying, a glycine powder may be easier.

Pros:

• Provides 1,000 mg glycine per serving.
• Good option for long-term daily use.
• Third-party tested for microbes and heavy metals.
• Non-GMO and gluten-free.
• Simple ingredient profile.

Cons:

• Single-ingredient formula only.
• Not the best fit for people who want glycine plus NAC.
• Higher-dose users may need several capsules.

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4. Best Clean Label: Pure Encapsulations Glycine

Best for: Sensitive users who want a clean-label glycine supplement from a well-known professional supplement brand.

Pure Encapsulations Glycine is a good clean-label option for people who are sensitive to extra ingredients. Each serving provides 1,500 mg of glycine, which sits between common 1,000 mg options and higher 3,000 mg routines.

The formula is vegan, gluten-free, and free from common allergens. That makes it appealing for people who prefer minimal formulas and careful ingredient standards.

The 1,500 mg serving also gives it a nice middle ground. Some readers may want more than 1,000 mg but do not want to go straight to 3,000 mg. Pure Encapsulations fits that space well.

The main drawback is cost. Clean-label brands can be more expensive than budget options. Also, some people may need more capsules to reach their preferred amount.

Pros:

• Provides 1,500 mg glycine per serving.
• Vegan and gluten-free.
• Free from common allergens.
• Good fit for ingredient-sensitive users.
• Useful middle-ground dose.

Cons:

• Can cost more than basic glycine capsules.
• May require more capsules depending on your target dose.
• No NAC or added antioxidant support.

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5. Best Higher Dose: NOW Foods Glycine

Best for: People who want the option to reach 3,000 mg daily using capsules.

NOW Foods Glycine is the best higher-dose option on this list because it gives readers flexible dosing. Each capsule provides 1,000 mg of glycine, and the suggested use allows 1 to 3 capsules daily.

Clinical studies have reported that 3,000 mg of glycine before bed was associated with improved subjective sleep quality, faster sleep onset, and less next-day fatigue in some adults.

That does not mean every person needs 3,000 mg. It means NOW Foods is a practical choice for people who already tolerate glycine well and want to use an amount closer to sleep-focused research.

NOW Foods Glycine uses free-form glycine and comes in vegan capsules. The brand also has GMP quality standards, which is helpful for shoppers who care about manufacturing practices.

The tradeoff is capsule count. If you want 3,000 mg, you may need to take 3 capsules. Some people will not mind. Others may prefer powder.

Pros:

• Provides 1,000 mg glycine per capsule.
• Suggested use allows 1 to 3 capsules daily.
• Can help users reach 3,000 mg without powder.
• Vegan capsules.
• GMP quality standards.

Cons:

• Higher-dose use means taking multiple capsules.
• Beginners may prefer starting with 1,000 mg.
• No NAC or additional cellular health support.

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6. Best Research Focused: Life Extension Glycine

Best for: People who want plain glycine from a science-focused supplement brand.

Life Extension Glycine is a good choice for readers who like research-led supplement brands. Each capsule provides 1,000 mg of glycine, which makes it easy to adjust intake based on personal preference.

Life Extension positions glycine around relaxation and sleep quality, while keeping the formula straightforward. Certificates of analysis are also available, which adds another layer of transparency for careful buyers.

This supplement may suit people who want a simple glycine capsule without added ingredients. It is also a good fit for readers who prefer brands that explain ingredient choices through a research-first lens.

The limitation is the same as other single-ingredient products. You do not get NAC, magnesium, or other supportive compounds. If your goal is plain glycine, that is fine. If your goal is GlyNAC-style support, Omre is the stronger match.

Pros:

• Provides 1,000 mg glycine per capsule.
• Research-focused brand positioning.
• Certificates of analysis are available.
• Simple capsule format.
• Good choice for plain glycine users.

Cons:

• No added NAC.
• May not appeal to people looking for a higher-dose formula.
• Not as complete as a glycine plus NAC formula.

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What Is Glycine?

Glycine is an amino acid. More specifically, it is a nonessential amino acid, which means the body can make it on its own. You can also get glycine from protein-containing foods and dietary supplements.

The body uses glycine for several normal functions, including:

• Protein production
• Collagen formation
• Nervous system signaling
• Glutathione production
• Creatine production
• Bile acid support
• General cellular function

As a supplement, glycine is commonly used by people looking for gentle support with sleep, relaxation, and recovery.

For sleep, glycine appears to work differently from strong sleep aids. Research suggests it may help the body settle down by supporting calming nervous system activity and helping lower core body temperature before sleep (1).

That cooling effect may be one reason some people report falling asleep more comfortably after taking glycine.

What Are Glycine Supplements Used For?

Most people compare glycine supplements for one of four reasons: sleep, relaxation, recovery, or antioxidant support.

Sleep and Relaxation Support

Glycine has been studied for sleep quality, sleep onset, next-day tiredness, and daytime alertness. Some clinical studies used 3,000 mg before bed and found improvements in subjective sleep quality and next-day fatigue (2).

This does not mean glycine works like a sleeping pill. It is better understood as a gentle amino acid that may help support the body's natural wind-down process.

Nervous System Support

Glycine acts as a signaling molecule in the nervous system. It can interact with receptors involved in calming activity, which is one reason it is discussed in relation to relaxation and sleep (3).

This effect can vary by person. Some people feel a noticeable difference at night. Others may not feel much.

Collagen and Protein Support

Glycine is one of the major amino acids found in collagen (4). Collagen is an important structural protein in skin, joints, connective tissue, and other parts of the body.

That does not mean a glycine capsule replaces collagen protein. It simply means glycine plays a role in the body's normal collagen-related processes.

Glutathione and Antioxidant Support

Glycine is one of the amino acids the body uses to make glutathione. NAC supplies cysteine, another important glutathione building block.

That is why glycine plus NAC formulas are popular among people interested in antioxidant balance, oxidative stress support, and cellular health. Omre Glycine + NAC fits this category.

Glycine Dosage: How Much Should You Take?

A common glycine supplement dose is 1,000 mg to 3,000 mg per day.

Many people start with 1,000 mg, especially if they are new to amino acid supplements or sensitive to changes in their nighttime routine.

Some sleep-focused clinical studies used 3,000 mg of glycine before bed. That amount was associated with better sleep quality and reduced next-day fatigue in some adults. Still, more is not always the better place to begin.

A simple way to think about it:

Glycine Amount	Common Use Case	Notes
1,000 mg	Starter dose	Easy to take, common in capsule products
1,500 mg	Middle-ground amount	Useful for people who want more than 1,000 mg
3,000 mg	Sleep-focused research amount	May require several capsules or powder

If you are using glycine for sleep, many people take it 30 to 60 minutes before bed. If you have a medical condition, take medication, or use sleep aids, speak with a healthcare professional before adding it.

Glycine Capsules vs Powder: Which Is Better?

Glycine capsules and glycine powder can both work. The better choice depends on your dose and your routine.

Capsules are better if you want convenience. They are pre-measured, taste-free, easy to travel with, and simple to take before bed.

Powder is better if you want flexible dosing. It can be easier to reach 3,000 mg with powder because you do not need to swallow several capsules.

Here is the simple breakdown:

Form	Best For	Tradeoff
Capsules	Convenience, travel, taste-free use	Higher doses may require multiple capsules
Powder	Flexible dosing and 3,000 mg routines	Requires measuring and has a taste
Glycine + NAC capsules	Combined cellular and antioxidant support	Not ideal for people who want glycine alone

For most people, capsules are easier to stick with. For higher-dose sleep routines, powder may feel more practical. For people who want glycine plus NAC, Omre gives a combined formula without needing two separate bottles.

Glycine vs GlyNAC: What's the Difference?

Glycine is a single amino acid. GlyNAC refers to a combination of glycine and N-acetyl cysteine, also called NAC.

The body uses glycine, cysteine, and glutamate to make glutathione. Glutathione is one of the body's main antioxidant compounds. NAC supplies cysteine. Glycine supplies glycine. That is the simple reason the pairing makes sense.

Research on GlyNAC has looked at areas such as glutathione status, oxidative stress markers, mitochondrial function, and physical function, especially in older adults (4). This research is still developing, so it should not be presented as a cure or a guaranteed anti-aging solution.

A careful way to say it is this: glycine plus NAC may support the body's glutathione production and antioxidant balance, especially when used as part of a broader healthy routine.

That is why Omre Glycine + NAC stands out in this list. It is not just plain glycine with an extra ingredient thrown in. The pairing has a clear biological reason behind it.

How to Choose the Best Glycine Supplement

The best glycine supplement is not always the one with the largest dose. A better choice comes down to dose clarity, quality standards, and how well the product fits your routine.

Check the Supplement Facts Panel

Look for the exact amount of glycine per serving. Do not rely only on the front label.

Check:

• Glycine amount
• Serving size
• Capsules per serving
• Servings per bottle
• Added ingredients
• Allergen information
• Suggested use

This helps you compare products fairly.

Decide Between Plain Glycine and Glycine + NAC

Plain glycine is best if you want one ingredient. Glycine + NAC is best if you want support for glutathione production, antioxidant balance, and cellular health. Omre Glycine + NAC is the strongest pick for that use case.

Look for Testing and Quality Standards

Good supplement brands should be clear about quality. Look for terms like:

• Third-party tested
• Tested for heavy metals
• Tested for microbes
• GMP-compliant manufacturing
• Certificate of analysis
• Made in the USA
• Allergen-free or free from common allergens

These details matter more than flashy label claims.

Think About Capsule Count

A 1,000 mg capsule sounds simple, but a 3,000 mg routine may require 3 capsules. That is fine if you do not mind capsules. If you dislike swallowing pills, glycine powder may be easier.

Avoid Overloaded Proprietary Blends

A glycine supplement does not need a long list of trendy ingredients. If a product includes added ingredients, they should have a clear purpose.

NAC makes sense with glycine because both relate to glutathione production. A random kitchen-sink sleep blend may be harder to evaluate.

Glycine Side Effects and Safety

Glycine is generally considered well tolerated at common supplemental amounts for many healthy adults. Still, individual responses can vary.

Possible side effects may include:

• Mild stomach upset
• Nausea
• Loose stool
• Sleepiness
• Headache
• Unusual dreams in some people

A lower starting dose may make sense if you are sensitive to supplements.

Speak with a healthcare professional before taking glycine if you are pregnant, nursing, taking medication, using sleep aids, managing a medical condition, or planning to take higher amounts.

Extra caution also makes sense with Glycine + NAC formulas. NAC may not suit everyone, especially people taking certain medications or managing specific health conditions.

Dietary supplements are not meant to diagnose, treat, cure, or prevent disease.

Final Words

The best glycine supplement depends on what you want from it.

If you want the simplest budget option, Nutricost L-Glycine is easy to understand. If you want a larger daily-use bottle, Double Wood Supplements Glycine is a strong value pick.

If you care most about clean-label standards, Pure Encapsulations Glycine is worth considering. If you want flexible dosing up to 3,000 mg, NOW Foods Glycine makes sense. If you prefer a research-focused brand, Life Extension Glycine is a solid plain-glycine option.

Omre Glycine + NAC is our best overall pick because it does more than provide basic glycine. It combines 1,000 mg of glycine with 500 mg of NAC, giving readers a simple way to support relaxation, antioxidant balance, glutathione production, and cellular health in one formula.

FAQs

Is glycine good for sleep?

Glycine may support sleep by helping the body relax and settle into a more restful state. Clinical studies have reported that 3,000 mg of glycine before bed was associated with improved sleep quality, faster sleep onset, and reduced next-day fatigue in some adults.

How much glycine should I take before bed?

Many glycine supplements provide 1,000 mg to 3,000 mg per serving. Some sleep-focused clinical studies used 3,000 mg before bed, but beginners may prefer starting with 1,000 mg to assess comfort and tolerance.

Is 1,000 mg of glycine enough?

For many people, 1,000 mg is a reasonable starting amount. It may be enough for a simple daily routine, especially for beginners. People looking for a sleep-focused amount closer to clinical research may consider 3,000 mg, with healthcare guidance if needed.

Is 3,000 mg of glycine too much?

Some clinical studies used 3,000 mg before bed, and that amount was associated with sleep-related benefits in some adults. Still, not everyone needs 3,000 mg. Starting lower is a more cautious approach, especially for people new to glycine.

Is glycine better in capsules or powder?

Capsules are easier for most people because they are pre-measured, taste-free, and simple to take before bed. Powder gives more dosing flexibility and may be easier for people targeting 3,000 mg, but it requires measuring.

What is the difference between glycine and NAC?

Glycine is an amino acid involved in protein production, nervous system signaling, collagen formation, and glutathione production. NAC, or N-acetyl cysteine, supplies cysteine, another amino acid the body uses to make glutathione.

What is GlyNAC?

GlyNAC refers to glycine plus N-acetyl cysteine. The body uses both glycine and cysteine to help make glutathione. GlyNAC has been studied for antioxidant balance, glutathione status, oxidative stress markers, and cellular health, especially in older adults.

Is glycine the same as magnesium glycinate?

No. Glycine is an amino acid. Magnesium glycinate is a form of magnesium bound to glycine. Both are discussed for sleep and relaxation, but they are different supplements.

Can I take glycine every night?

Many healthy adults tolerate glycine at common supplemental amounts, but responses can vary. People who are pregnant, nursing, taking medication, using sleep aids, or managing a medical condition should speak with a healthcare professional first.