Magnesium glycinate and magnesium citrate are two of the most popular and well-absorbed magnesium supplements — but they’re not interchangeable. They work through different mechanisms, suit different needs, and have meaningfully different effects on your digestive system.
If you’re trying to decide between them, the answer is usually straightforward once you know what each one actually does.
Quick Comparison
| Magnesium Glycinate | Magnesium Citrate | |
|---|---|---|
| Also known as | Magnesium bisglycinate, magnesium chelate | Magnesium citrate salt |
| Bound to | Glycine (amino acid) | Citric acid |
| Absorption | High | Moderate–High |
| GI tolerance | Excellent — minimal laxative effect | Moderate — osmotic laxative effect |
| Best for | Sleep, anxiety, daily use | Constipation, general use |
| Speed of effect | Gradual, long-term | Faster, especially on digestion |
| Elemental Mg per dose | Lower (chelation adds weight) | Higher per gram of compound |
What Is Magnesium Glycinate?
Magnesium glycinate (also called magnesium bisglycinate or magnesium chelate) is magnesium bound to glycine, a naturally occurring amino acid. This chelated bond improves how the magnesium is absorbed through the intestinal wall and significantly reduces how much unabsorbed magnesium reaches the colon — which is what causes the laxative effect common with cheaper forms.
Glycine is an inhibitory neurotransmitter with calming properties. It supports GABA activity in the brain — the same pathway involved in sleep and relaxation. So magnesium glycinate provides two compounds with overlapping benefits in a single supplement.
This makes it the preferred choice for:
- Sleep quality and duration
- Anxiety and stress management
- Muscle relaxation and recovery
- Daily long-term supplementation
- Anyone who has experienced digestive issues with other magnesium forms
Our Magnesium Glycinate provides 55mg elemental magnesium per capsule — vegan, UK-made, with no artificial fillers.
What Is Magnesium Citrate?
Magnesium citrate is magnesium bound to citric acid. It’s highly water-soluble, which contributes to good absorption in the gut. It’s also osmotic — meaning it draws water into the intestines, softening stools and stimulating bowel movements.
This laxative effect is the defining feature of magnesium citrate. At lower doses it’s mild enough to help with regularity without causing urgency. At higher doses — as used in bowel prep formulas — the effect is much more pronounced.
A clinical trial published in the Journal of the American College of Nutrition found magnesium citrate to be among the most bioavailable forms tested, comparable to glycinate in terms of raising serum magnesium levels.
This makes it the preferred choice for:
- Constipation or sluggish digestion
- General magnesium supplementation when digestive tolerance isn’t an issue
- People who prefer powdered or liquid supplement formats
Head-to-Head: Key Differences
Absorption
Both forms are well-absorbed compared to magnesium oxide. Glycinate’s chelated structure provides consistent absorption across different gut conditions. Citrate is highly soluble and absorbs efficiently, particularly with food or in liquid form. For raising magnesium levels, both are effective — the difference is more about tolerability than absorption rate.
Effect on Digestion
This is the most practical difference. Magnesium citrate’s osmotic action in the colon is useful if you need digestive support — but inconvenient if you don’t. Glycinate bypasses this issue almost entirely. If loose stools or urgency are a concern, glycinate is the clear choice.
Sleep and Relaxation
Glycinate has an advantage here. Glycine independently promotes sleep — a 2012 study in Sleep and Biological Rhythms found that glycine taken before bed improved sleep quality and reduced daytime sleepiness. Combined with magnesium’s effect on GABA receptors and cortisol suppression, glycinate is better suited to evening use for sleep support. For more detail, see our post on why magnesium may be better than melatonin for sleep, and our magnesium glycinate sleep dosage guide for specific timing and dosing.
Muscle Recovery
Both forms support muscle function through magnesium’s role in muscle relaxation post-contraction. Neither has a clear advantage here — the form matters less than getting sufficient elemental magnesium consistently. See our guide to magnesium for muscle recovery.
Cost
Magnesium citrate is typically cheaper to manufacture, making it more common in budget supplements. Glycinate costs more due to the chelation process, but the price difference in quality supplements is usually modest.
Which Should You Choose?
Choose magnesium glycinate if:
- You want to support sleep quality or reduce anxiety
- You’ve had digestive issues with other magnesium supplements
- You’re taking magnesium long-term as a daily supplement
- You’re over 40 and looking for the most gut-friendly option
Choose magnesium citrate if:
- You experience constipation and want digestive support alongside magnesium
- You prefer powders or liquids over capsules
- Digestive tolerance is not a concern for you
If you’re unsure, glycinate is the safer default for most people. The digestive gentleness and glycine’s added benefits make it the better all-round choice for daily supplementation without a specific digestive goal.
Dosage and Timing
Glycinate: Best taken in the evening with food. The calming effect of both magnesium and glycine complements sleep. Starting dose: 1–2 capsules (200–400mg of compound, providing 55–110mg elemental magnesium).
Citrate: Best taken earlier in the day if using for constipation — the laxative effect can take 30 minutes to 6 hours. If using purely as a magnesium supplement, timing is flexible.
The NHS recommends 270mg/day for women and 300mg/day for men of total magnesium. The EU’s tolerable upper intake level for supplemental magnesium is 250mg/day from supplements. Always check the elemental magnesium content on the label, not just the compound weight.
FAQ
Q: Is magnesium glycinate better than magnesium citrate?
A: For most people taking magnesium for sleep, stress, or general health, glycinate is the better choice — it’s gentler on the digestive system and the glycine component adds calming benefits. Citrate is better if constipation is a factor.
Q: Can I take magnesium glycinate and citrate together?
A: You can, but it’s rarely necessary. The main reason to combine them is if you want the digestive benefits of citrate alongside the sleep and relaxation benefits of glycinate. Start with one form first to assess how your body responds.
Q: What is magnesium bisglycinate — is it the same as glycinate?
A: Yes. Magnesium bisglycinate is another name for magnesium glycinate — it refers to the fact that two glycine molecules are bound to each magnesium ion. Some manufacturers use one name, some the other. They’re the same compound.
Q: Which is better for sleep — glycinate or citrate?
A: Glycinate. The combination of magnesium’s GABA-supporting effects and glycine’s independent calming properties makes glycinate the better choice for sleep. Citrate can cause digestive activity that may disrupt sleep if taken in the evening.
Q: How long does it take for magnesium to work?
A: For digestive effects, citrate can work within a few hours. For sleep, mood, and muscle benefits, expect to take magnesium consistently for 2–4 weeks before noticing meaningful improvement. Magnesium isn’t a one-dose supplement — it works by correcting a chronic shortfall over time.
References
- Coudray C, et al. (2005). Study of magnesium bioavailability from ten organic and inorganic Mg salts. Magnesium Research, 18(4), 215–223.
- Walker AF, et al. (2003). Mg citrate found more bioavailable than other Mg preparations. Magnesium Research, 16(3), 183–191.
- Inagawa K, et al. (2006). Subjective effects of glycine ingestion before the sleep period. Sleep and Biological Rhythms, 4(1).
- NHS. Vitamins and minerals — Magnesium.
This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any supplement, especially if you are pregnant, have a medical condition, or take prescription medication.
