Glycine and magnesium glycinate are not the same thing. Glycine is an amino acid you can take on its own, while magnesium glycinate is magnesium bound to glycine. Magnesium glycinate does supply some glycine, but much less than sleep studies used: in one trial, 250 mg of magnesium as bisglycinate came with about 1.5 g of glycine, half of the 3 g given in glycine sleep studies.
Key Takeaways
- Glycine is a non-essential amino acid; magnesium glycinate (also sold as bisglycinate) is the mineral magnesium attached to glycine (Bannai and Kawai, 2012).
- In a 2025 trial, 250 mg of magnesium as magnesium bisglycinate came with 1,523 mg of glycine, about 6 mg of glycine for every 1 mg of magnesium (Schuster et al., 2025).
- Glycine sleep studies used 3 g before bed. Getting that much from magnesium glycinate would take about 490 mg of magnesium, above the 350 mg upper limit for supplemental magnesium (NIH ODS).
- They do different jobs, so many people take both in the evening: magnesium for the mineral, glycine for a full study amount of the amino acid.
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Is Glycine the Same as Magnesium Glycinate?
No. Glycine is an amino acid your body makes, so it is called non-essential, and it acts as a messenger in the nervous system (Bannai and Kawai, 2012). You can buy it on its own as a plain powder. Our guide to glycine benefits covers everything else it does.
Glycinate is the name for glycine when it is bound to a mineral. Magnesium glycinate, often labeled magnesium bisglycinate, is magnesium held by two glycine molecules. The point of the glycine is to carry the magnesium, so the label lists the amount of magnesium, not the amount of glycine. Our guide to magnesium bisglycinate vs glycinate explains the label terms, and the same glycinate idea applies to zinc bisglycinate.
Glycine vs Magnesium Glycinate at a Glance
| Glycine | Magnesium glycinate | |
|---|---|---|
| What it is | An amino acid | A mineral bound to glycine |
| Main reason to take it | Glycine itself | Magnesium, a cofactor in more than 300 enzyme systems |
| Amount studied for sleep | 3 g before bed | 250 mg of magnesium, 30 to 60 minutes before bed |
| Glycine per serving | All of it | About 6 mg for each 1 mg of magnesium |
| Daily limit to know | No official upper limit | 350 mg of supplemental magnesium for adults |
How Much Glycine Is in Magnesium Glycinate?
The clearest real-world figure comes from a 2025 trial: its daily dose of magnesium bisglycinate gave 250 mg of magnesium and 1,523 mg of glycine (Schuster et al., 2025). That works out to about 6 mg of glycine for every 1 mg of magnesium. Using that ratio:
| Magnesium on the label (as bisglycinate) | Glycine it carries (about) | Share of the 3 g used in sleep studies |
|---|---|---|
| 100 mg | 610 mg | About a fifth |
| 200 mg | 1,220 mg | About two fifths |
| 250 mg (the 2025 trial) | 1,523 mg | About half |
| 350 mg (the upper limit) | 2,130 mg | About seven tenths |
To reach 3 g of glycine from magnesium glycinate alone, you would need about 490 mg of magnesium, which is above the 350 mg a day upper limit that NIH sets for magnesium from supplements (NIH ODS). Products that blend glycinate with other forms of magnesium carry even less glycine per milligram of magnesium. So if you want the glycine amount used in sleep studies, plain glycine is the practical way to get it.
Glycine vs Magnesium Glycinate for Sleep
Glycine. In people who had been sleeping poorly, 3 g of glycine before bed shortened the time to fall asleep and to reach deep sleep, and lessened daytime sleepiness (Yamadera et al., 2007). In a crossover trial, 7 healthy men whose time in bed was cut by 25% for three nights took 3 g of glycine 30 minutes before bed and reported less fatigue, with better reaction times the next day (Bannai et al., 2012). In rats, glycine lowered core body temperature and increased blood flow to the skin, which researchers suggest may help, since body temperature normally drops as sleep begins (Bannai and Kawai, 2012). See glycine for sleep for more.
Magnesium glycinate. In 155 adults aged 18 to 65 who reported poor sleep, 250 mg of magnesium as bisglycinate taken 30 to 60 minutes before bed for 4 weeks improved a sleep questionnaire score more than placebo. The effect was small, and people with lower magnesium intake from food seemed to improve more in an exploratory analysis (Schuster et al., 2025). That trial's dose also carried about 1.5 g of glycine, so the two may have worked together. Our guide to magnesium glycinate for sleep goes deeper.
Taking Glycine and Magnesium Glycinate Together
Yes, you can take them together, and they suit the same time of day: both were studied in the 30 to 60 minutes before bed. A few points make it simple:
- Count the glycine from both. 200 mg of magnesium as glycinate adds about 1.2 g of glycine to whatever plain glycine you take.
- Keep supplemental magnesium at or under 350 mg a day unless your clinician advises otherwise. Food magnesium does not count toward that limit.
- Get magnesium from food too. Adult women need 310 to 320 mg a day and men 400 to 420 mg, and 48% of Americans get less than they need from food and drinks (NIH ODS).
Who Might Choose Which
| If you | Consider |
|---|---|
| Want the glycine amount used in sleep studies | Plain glycine, 3 g before bed |
| Eat few greens, nuts, seeds or whole grains | Magnesium glycinate, a gentle form of magnesium |
| Want a full evening routine | Both, taken together 30 to 60 minutes before bed |
Safety and Side Effects
Most people tolerate both well. In the 2025 magnesium bisglycinate trial, 93% of participants reported no side effects and there were no serious events (Schuster et al., 2025). NIH lists magnesium carbonate, chloride, gluconate and oxide as the forms most likely to loosen stools, and notes that healthy kidneys clear extra magnesium, while the risk of too much rises when kidney function is reduced (NIH ODS). Our guide to magnesium glycinate side effects has the details. Talk with your clinician first if you have kidney concerns, are pregnant or breastfeeding, or take prescription medicine.
Where Our Products Fit
Our Melatonin-Free Sleep Powder, coming soon, gives you both in one drink: 3 g of glycine, the amount used in the sleep studies above, plus 200 mg of magnesium from two gentle forms, with tart cherry, myo-inositol and apigenin. Mix it in water 30 to 60 minutes before bed. It has no added melatonin, no 5-HTP and no added sugar or sweeteners. Join the waitlist on the product page to hear when it launches.
Our Vitamin D Cofactor Capsules, also coming soon, use the glycinate approach for minerals: magnesium 100 mg and zinc 10 mg as bisglycinate, plus boron 3 mg as glycinate, per 2 capsules, made to pair with our Vitamin D3 + K2 Drops. Join the waitlist to hear when they launch. Benefits from daily minerals build with consistent use: months 1 to 2 can bring early changes, and 3 months and beyond is where the full benefit builds. See our glycine ingredient page and sleep health hub for more.
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Vitamin D Cofactor CapsulesMagnesium 100 mg, zinc 10 mg and boron 3 mg per 2 capsules, all as glycinates, made to pair with vitamin D3.
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Frequently Asked Questions
Is glycine the same as magnesium glycinate?
No. Glycine is an amino acid; magnesium glycinate is magnesium bound to glycine. The glycinate form supplies some glycine, but the label amount is the magnesium.
What is the difference between glycine and glycinate?
Glycinate is glycine attached to a mineral, such as magnesium or zinc. Glycine on its own is the free amino acid.
How much glycine is in magnesium glycinate?
About 6 mg of glycine for each 1 mg of magnesium, based on a 2025 trial in which 250 mg of magnesium came with 1,523 mg of glycine.
Glycine vs magnesium glycinate for sleep: which is better?
They were studied differently: glycine at 3 g before bed, magnesium bisglycinate at 250 mg of magnesium. Many people take both, since they do different jobs.
Can I take glycine and magnesium glycinate together?
Yes. Take them together 30 to 60 minutes before bed, count the glycine from both, and keep supplemental magnesium at or under 350 mg a day.
Can magnesium glycinate replace a glycine supplement?
Not for the amount used in sleep studies. Reaching 3 g of glycine would take about 490 mg of magnesium, above the 350 mg upper limit.
Is magnesium bisglycinate the same as magnesium glycinate?
The terms are used for the same idea, magnesium bound to glycine. Our bisglycinate vs glycinate guide explains how labels differ.
When should I take glycine and magnesium glycinate?
In the evening. Glycine was studied 30 minutes before bed and magnesium bisglycinate 30 to 60 minutes before bed.
Sources
- Bannai M, Kawai N. New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep. Journal of Pharmacological Sciences, 2012. https://doi.org/10.1254/jphs.11R04FM
- Schuster J, Cycelskij I, Lopresti A, Hahn A. Magnesium bisglycinate supplementation in healthy adults reporting poor sleep: a randomized, placebo-controlled trial. Nature and Science of Sleep, 2025. https://doi.org/10.2147/NSS.S524348
- Yamadera W, Inagawa K, Chiba S, et al. Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes. Sleep and Biological Rhythms, 2007. https://doi.org/10.1111/j.1479-8425.2007.00262.x
- Bannai M, Kawai N, Ono K, Nakahara K, Murakami N. The effects of glycine on subjective daytime performance in partially sleep-restricted healthy volunteers. Frontiers in Neurology, 2012. https://doi.org/10.3389/fneur.2012.00061
- NIH Office of Dietary Supplements. Magnesium: Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/
These statements have not been evaluated by the Food and Drug Administration. This content is for education and is not medical advice. Our products are not intended to diagnose, treat, cure or prevent any disease. Talk with a healthcare provider before starting a new supplement if you are pregnant, breastfeeding or taking medication.
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