If you are looking for the best glycine supplement, start with the basics: clear dosing, clean ingredients, and a formula you can take consistently.

Glycine is a naturally occurring amino acid that many people use for sleep, relaxation, and general wellness support. Some products keep it simple with glycine alone, while others, like Omre Glycine + NAC, pair it with added support for antioxidant and cellular health.

Key Takeaways:

• Omre Glycine + NAC is our best overall pick because it combines 1,000 mg of glycine with 500 mg of NAC.
• Most glycine supplements provide 1,000 mg to 3,000 mg per serving.
• Clinical studies have reported that 3,000 mg of glycine before bed was associated with better sleep quality and faster sleep onset in some adults (1).
• The best choice depends on your dose preference, ingredient needs, testing standards, and daily routine.

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 also paid close attention to dose, capsule convenience, and ingredient quality.

Clear Glycine Dose

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

Testing and Quality Standards

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

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 goals.

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.

Best Glycine Supplement: 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

Here is a quick side-by-side look before we review each product.

1. Best Overall: Omre Glycine + NAC

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, while NAC is commonly used to support glutathione production. Glutathione plays a role in antioxidant balance, so this formula fits well for people who want nighttime support plus broader daily wellness support.

The formula is made in the USA in GMP-compliant facilities, uses vegetarian capsules, and is free from common allergens. For readers who want a simple but more complete option, Omre Glycine + NAC is a strong place to start.

Pros:

• Combines 1,000 mg glycine with 500 mg NAC.
• Supports sleep, relaxation, antioxidant balance, and cellular health.
• Vegetarian capsules and 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 glycine with no added actives.

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2. Best Budget: Nutricost L-Glycine

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 dose for sleep and relaxation support.

The formula is vegetarian, non-GMO, gluten-free, and third party tested. It does not try to be fancy, which is part of the appeal.

This may be a good fit for someone trying glycine for the first time or anyone who wants a low-cost option for daily use.

Pros:

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

Cons:

• No added ingredients for broader support.
• Lower dose than 3,000 mg sleep-focused study amounts.

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3. Best Value Size: Double Wood Glycine Supplements 

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.

The brand notes third party testing for microbes and heavy metals. It is also made in the USA with globally sourced ingredients, and the formula is non-GMO and gluten-free.

This option makes sense for readers who want a straightforward glycine supplement in a larger bottle, especially if they already know glycine fits their routine.

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.

Cons:

• Single-ingredient formula only.
• Not the best fit for people who want a higher glycine dose per serving.

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4. Best Clean Label: Pure Encapsulations Glycine

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 products.

The formula is vegan, gluten-free, and free from common allergens. That makes it appealing for people who want a more minimal ingredient list.

This product may suit readers who want a slightly higher glycine dose without moving straight to a 3,000 mg serving.

Pros:

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

Cons:

• May require more capsules per serving.
• Usually costs more than basic budget options.

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5. Best Higher Dose: NOW Foods Glycine

NOW Foods Glycine is the best higher-dose option on this list. Each serving provides 3,000 mg of glycine, which matches the amount used in some sleep-focused research.

Clinical studies have reported that 3,000 mg of glycine taken before bed was associated with faster sleep onset and improved sleep quality in some adults. That does not mean everyone needs this amount, but it does make NOW Foods a practical option for people who already prefer a higher glycine dose.

The product uses free-form glycine, is described as pharmaceutical grade, and comes in vegan capsules. NOW Foods also has GMP certification for its manufacturing practices.

Pros:

• Provides 3,000 mg glycine per serving.
• Matches the dose used in some sleep-focused clinical research.
• Vegan capsules.
• GMP-certified manufacturing.

Cons:

• Higher dose may not suit beginners.
• Some people may prefer starting with 1,000 mg first.

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6. Best Research Focused: Life Extension Glycine

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.

The brand 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 science-guided brand, a simple dose, and a product that does not add extra ingredients.

Pros:

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

Cons:

• No added support ingredients like NAC.
• May not appeal to people looking for a higher-dose formula.

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What Is Glycine?

Glycine is an amino acid that your body uses for many normal functions, including protein production, nervous system signaling, and collagen formation.

It is found naturally in the body and also comes from foods that contain protein. 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 (2). That cooling effect may be one reason some people report falling asleep more comfortably after taking it.

Glycine Dosage: How Much Should You Take?

A common glycine supplement dose is 1,000 mg to 3,000 mg per day, with some sleep-focused clinical studies using 3,000 mg before bed.

That said, more is not always the better place to begin. Many people start with 1,000 mg to see how their body responds, especially if they are new to glycine or sensitive to supplements. 

A 3,000 mg serving may suit people who already tolerate glycine well and want a dose closer to amounts used in some sleep research.

Final Words

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

If you want the simplest low-cost option, Nutricost is easy to understand. If you want a higher dose, NOW Foods gives you 3,000 mg per serving. If you care most about clean-label standards, Pure Encapsulations is a strong pick. Life Extension and Double Wood also make sense for readers who want simple, steady glycine support.

At Omre, we designed Glycine + NAC for people who want a little more from their nightly routine. It combines 1,000 mg of glycine with 500 mg of NAC, so you get gentle sleep support along with antioxidant and cellular health support in one simple formula.

If you want a research-aligned option that fits into daily use without overcomplicating things, Omre Glycine + NAC is our top pick.

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 and faster sleep onset 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 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, but it requires measuring and may not be as convenient at night.

Can I take glycine every night?

Glycine is generally considered well tolerated at common supplemental doses for many healthy adults. Still, individual responses can vary, and anyone who is pregnant, nursing, taking medication, or managing a medical condition should speak with a healthcare professional first.

What is the difference between glycine and NAC?

Glycine is an amino acid involved in protein production, nervous system signaling, and relaxation support. NAC, or N-acetyl cysteine, is commonly used to support glutathione production, which plays a role in antioxidant balance.