Magnesium Bisglycinate vs Magnesium Glycinate: What’s the Difference, and Which Should You Buy?

Walk into any supplement aisle and you’ll see two labels that look almost the same: magnesium glycinate and magnesium bisglycinate. Are they different products, or just two names for the same thing?

Most of the time, they’re functionally the same form of magnesium: magnesium bound to the amino acid glycine. But labels, dosing, and quality can vary enough that it’s worth knowing what you’re actually buying. This guide breaks down magnesium bisglycinate vs magnesium glycinate in plain English, with practical tips you can use right away.

Why magnesium form matters

Magnesium helps your nerves fire, your muscles relax, and your cells make energy. Yet many people fall short on intake. The NIH Office of Dietary Supplements covers magnesium’s roles, food sources, and recommended intakes if you want the bigger picture.

When you supplement, the form matters because it affects:

• How well your gut absorbs it
• How likely it is to cause loose stools
• How much “elemental magnesium” you get per pill
• How consistent the product is from brand to brand

Magnesium glycinate (and bisglycinate) is popular because many people find it gentle on the stomach and easy to take at night.

Magnesium glycinate vs magnesium bisglycinate: the simple definition

What is magnesium glycinate?

Magnesium glycinate usually means magnesium bound to glycine. Glycine is a small amino acid. When magnesium binds to amino acids, it forms a “chelate,” which can improve tolerance for some people.

What is magnesium bisglycinate?

Magnesium bisglycinate is a more specific name. “Bis” suggests two glycine molecules attached to one magnesium ion. In everyday supplement talk, magnesium bisglycinate is a type of magnesium glycinate.

So are they the same?

Often, yes. Many brands use the terms interchangeably. But labels don’t always tell the full story. One product may be a true fully reacted chelate, while another may be a blend (for example, partly magnesium oxide mixed with glycine). That difference can affect both absorption and how your stomach feels.

What you actually need to check on the label

If you’re trying to choose between magnesium bisglycinate vs magnesium glycinate, don’t stop at the front label. Flip the bottle and look for details that hint at quality.

1) Elemental magnesium per serving

Supplement labels list “magnesium (as magnesium glycinate)” followed by an amount in milligrams. That number is elemental magnesium, the part your body uses.

Two bottles can both say “magnesium glycinate,” yet one provides 100 mg per capsule and another provides 200 mg. Neither is “better” by default, but you need the number to dose correctly.

2) “Fully reacted” or “chelated” wording

Some brands use phrases like “fully reacted magnesium bisglycinate chelate.” That can be a sign (not a guarantee) that the magnesium is truly chelated rather than just mixed.

Be careful with vague phrases. “Buffered” can mean the product includes another magnesium form (often oxide) to raise elemental magnesium. That may still work, but it can change how well you tolerate it.

3) Third-party testing

Look for independent testing or quality seals. In the US, the FDA doesn’t approve supplements before sale, so quality checks matter. The FDA’s dietary supplement pages explain what supplement makers must (and don’t have to) do.

Absorption and gut tolerance: why people pick glycinate

Magnesium can pull water into the intestines. That’s why some forms, like magnesium citrate, commonly act as a laxative at higher doses. Glycinate and bisglycinate tend to be gentler for many people.

Research on chelated magnesium suggests amino acid chelates can be well absorbed. If you want a deeper, research-focused overview of magnesium forms and bioavailability, examine reviews like the one hosted by the National Library of Medicine (PubMed) and look for comparative studies on magnesium salts and chelates.

Real-world takeaway: if magnesium upsets your stomach or gives you diarrhea, glycinate or bisglycinate is often the first switch to try.

Benefits people look for: sleep, stress, cramps, and more

People buy magnesium for lots of reasons. Here’s where glycinate and bisglycinate usually fit best.

Sleep support

Many people take magnesium glycinate at night because it’s less likely to cause stomach issues and glycine itself may feel calming for some users. Don’t expect a knockout effect. Think of it as support for relaxation, not a sedative.

Stress and tension

Magnesium plays a role in nerve signaling and muscle relaxation. If you get tight shoulders, jaw tension, or a “wired” feeling late in the day, a glycinate form may be easier to stick with because it’s gentler.

Muscle cramps and exercise recovery

Cramping isn’t always magnesium. Hydration, sodium, training load, and sleep all matter. Still, if your diet runs low in magnesium-rich foods (nuts, beans, greens), a supplement can help fill the gap. Sports-focused outlets often cover practical magnesium use in training contexts, like this overview from Precision Nutrition.

Constipation (when glycinate is not the best choice)

If your main goal is to get things moving, magnesium glycinate may not be the best fit. Magnesium citrate often works better for occasional constipation, but you should be cautious with dosing. For bowel-related use, it’s smart to review guidance from a clinical source like the Cleveland Clinic’s magnesium citrate information and talk with a clinician if constipation is ongoing.

How to choose between magnesium bisglycinate vs magnesium glycinate

Since the two names overlap, the “right” choice usually comes down to product details and your goal.

Choose magnesium bisglycinate if you want clearer naming

Because “bisglycinate” is more specific, brands that use it sometimes provide better detail on sourcing and chelation. That’s not a rule, but it’s common.

Choose magnesium glycinate if the product is transparent and well tested

If a magnesium glycinate product clearly lists elemental magnesium, has third-party testing, and avoids mystery blends, it can be just as good.

A quick decision checklist

• If you have a sensitive stomach: pick glycinate/bisglycinate over oxide or citrate.
• If you need help with constipation: consider citrate instead of glycinate.
• If the label says “buffered” and you get diarrhea: try a different brand or a “fully reacted” chelate.
• If you take several supplements: choose a lower dose per capsule so you can adjust slowly.

How much to take (and how to avoid side effects)

Most people do best when they start low and move up.

Start low, then adjust

1. Start with 100-200 mg elemental magnesium per day.
2. Take it with food if your stomach is touchy.
3. After 3-7 days, increase in small steps if needed.

Common side effects include loose stools, stomach cramps, and nausea. Glycinate tends to cause fewer of these, but dose still matters.

Timing tips

• For sleep: take it 1-2 hours before bed.
• For daytime tension: split the dose, morning and evening.
• If it upsets your stomach: take it with your largest meal.

Drug interactions and who should be careful

Magnesium supplements can interact with some medicines by reducing absorption or changing how they work.

Separate from these meds (common examples)

• Thyroid hormone (like levothyroxine)
• Some antibiotics (tetracyclines and fluoroquinolones)
• Bisphosphonates used for bone health

A simple rule: take magnesium at least 2-4 hours apart from these meds unless your pharmacist tells you otherwise.

People who should talk to a clinician first

• Anyone with kidney disease or reduced kidney function
• People on multiple heart or blood pressure medicines
• Anyone pregnant or breastfeeding who wants higher doses

Your kidneys clear excess magnesium. If they don’t work well, magnesium can build up.

Food first: the easiest way to raise magnesium

Supplements help, but food still does a lot of the heavy lifting. Good sources include:

• Pumpkin seeds, almonds, cashews
• Black beans, lentils, chickpeas
• Spinach and other leafy greens
• Whole grains
• Dark chocolate (watch the added sugar)

If you want a quick way to estimate intake from food, a practical tool like the NutritionValue.org nutrient calculator can help you total your day and see if you’re consistently low.

Common label traps (and how to avoid them)

“Magnesium glycinate complex”

This can mean many things. Look for the Supplement Facts panel and check if it lists other forms like oxide, carbonate, or citrate. A blend isn’t always bad, but it may behave differently than you expect.

Huge elemental magnesium claims

If a product claims a very high dose per capsule, it may rely on cheaper forms or blends to get there. That may still suit you, but don’t assume “more” means “better.”

Not listing elemental magnesium clearly

If you can’t tell how many milligrams of elemental magnesium you’re getting, skip it. You can’t dose what you can’t measure.

FAQ

Is magnesium bisglycinate better than magnesium glycinate?

Not automatically. Many products are the same thing under different names. Quality, testing, and the exact formula matter more than the word on the front label.

Does magnesium glycinate make you sleepy?

Some people feel more relaxed, especially at night. Others feel nothing. It shouldn’t knock you out, but it may support sleep if low magnesium plays a role in your rest.

Can I take magnesium glycinate every day?

Many people do. Stay within a sensible dose, watch for loose stools, and check with a clinician if you have kidney issues or take interacting meds.

Conclusion

Magnesium bisglycinate vs magnesium glycinate often comes down to naming. Both usually refer to magnesium bound to glycine, a form many people tolerate well. The real difference shows up in the fine print: elemental magnesium per serving, whether the product is fully reacted or buffered, and whether the brand backs it up with solid testing.

If you want a calm, gut-friendly magnesium supplement, a well-made glycinate or bisglycinate is a safe bet for many people. Start with a low dose, take it consistently, and judge it by how you feel and how well you tolerate it, not by the marketing on the label.