Magnesium Glycinate 400mg vs Magnesium Bisglycinate 200mg
Side-by-side comparison of scores, ingredients, prices and real customer feedback for Magnesium Glycinate 400mg and Magnesium Bisglycinate 200mg.
Last verified: 07 Apr 2026 · Based on 85 reviews
Magnesium Glycinate 400mg scores 80.0/100 vs Magnesium Bisglycinate 200mg at 74.0/100. Magnesium Glycinate 400mg wins on effectiveness, value for money. Magnesium Bisglycinate 200mg is stronger on side effects and certifications.
Which is better: Magnesium Glycinate 400mg or Magnesium Bisglycinate 200mg?
Solgar wins with a higher overall score (80 vs 74) and a confirmed price of £12.25, making it the more practical choice for most buyers. Thorne's NSF Certified for Sport status makes it the better pick for competitive athletes requiring verified purity, though its lack of user reviews and unlisted price are real drawbacks.
— AIScored Editorial Team
How Do the Scores Compare?
Magnesium Glycinate 400mg
Solgar
|
Magnesium Bisglycinate 200mg
Thorne
|
|
|---|---|---|
| Overall Score | 80.0 | 74.0 |
| Effectiveness |
79.0/100
Best
|
71.0/100 |
| Ingredient Quality |
88.0/100
Best
|
88.0/100
Best
|
| Value for Money |
70.0/100
Best
|
60.0/100 |
| Side Effects | 76.0/100 |
86.0/100
Best
|
| Certifications | 84.0/100 |
90.0/100
Best
|
| Best Price |
£12.25
Amazon UK →
Cheapest
|
View → |
| Form | N/A | N/A |
| Dose | N/A | N/A |
| Third-Party Tested | ✗ No | ✗ No |
| Reviews Analysed | 76 | 9 |
Magnesium Glycinate 400mg
Pros
- ✓Strong user-reported improvement in sleep quality — faster onset and fewer nighttime awakenings
- ✓Effective at reducing leg cramps, muscle tension, and post-exercise soreness
- ✓Glycinate chelate offers high bioavailability and is generally gentle on the digestive system
- ✓Clean, minimal formula — gluten-free, dairy-free, non-GMO, kosher-certified; trusted Solgar brand
Cons
- ✗Paradoxical insomnia or restless sleep in a subset of users, possibly linked to MTHFR mutations or glycine sensitivity — magnesium threonate may suit these individuals better
- ✗Large tablet/capsule size noted as inconvenient by multiple reviewers
- ✗Premium brand pricing is higher than comparable chelated magnesium products
- ✗High doses may disrupt calcium balance, contributing to eye twitching or muscle symptoms in some users
Best For
Magnesium Bisglycinate 200mg
Pros
- ✓Bisglycinate chelate form offers superior absorption and bioavailability vs. oxide or sulfate forms
- ✓Minimal gastrointestinal side effects — significantly less likely to cause loose stools than cheaper magnesium forms
- ✓Thorne Research holds NSF Certified for Sport certification — rigorous third-party purity and potency verification
- ✓Free from common allergens, artificial additives, and unnecessary fillers
Cons
- ✗Premium price point — noticeably more expensive than standard magnesium oxide supplements
- ✗No usable product-specific user reviews available — provided reviews are from an unrelated UK beekeeping company
- ✗Multiple capsules per day may be needed to reach clinically studied therapeutic doses (310–420mg elemental)
- ✗Capsule size can be large for some users
Best For
What does the data say about Magnesium Glycinate 400mg vs Magnesium Bisglycinate 200mg?
Solgar's Magnesium Glycinate (400mg) and Thorne's Magnesium Bisglycinate (200mg) both use chelate forms that improve absorption, but the dose difference is significant. Solgar delivers 400mg per serving while Thorne offers 200mg — roughly a 2:1 ratio. Ingredient quality scores are identical at 88.0, but Solgar pulls ahead on overall score (80.0 vs 74.0) and effectiveness (79.0 vs 71.0). At £12.25, Solgar also provides better value per dose.
Pick Solgar if you need a stronger dose to tackle sleep problems, muscle cramps, or chronic stress. Users report faster sleep onset and fewer nighttime awakenings. The trade-off: some people experience paradoxical restlessness, possibly linked to glycine sensitivity, and the tablets are large. Thorne suits those preferring a lower dose or wanting a different chelate form, though its UK price isn't published online.
Both forms cause fewer digestive complaints than cheaper magnesium oxide, but individual tolerance varies significantly. Solgar's larger tablet size may frustrate people with swallowing difficulties, while Thorne's lower dose means multiple capsules to match Solgar's potency. Test your response carefully — magnesium affects sleep, muscle function, and digestion differently depending on your genetics and current status.
Solgar Magnesium Glycinate 400mg is a premium chelated magnesium supplement widely praised by reviewers for improving sleep quality, reducing muscle cramps, and easing nervous tension.
What are the key differences?
Frequently Asked Questions
Which is better, Magnesium Glycinate 400mg or Magnesium Bisglycinate 200mg? ▼
Is Magnesium Glycinate 400mg worth the price compared to Magnesium Bisglycinate 200mg? ▼
Which has fewer side effects? ▼
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What the Data Says
Why is magnesium oxide less effective than glycinate?
Oxide scores 21 points lower than glycinate in our testing — and it's not close on ingredient quality either. Across 17 magnesium products in our database, glycinate averages 74.3/100 overall. Oxide sits at 53/100. That's a gap you can feel.
The ingredient quality difference is even starker: 83.3 for glycinate vs 37.0 for oxide. A 46.3-point gap. The best glycinate in our database, Solgar Magnesium Glycinate 400mg, scores 80/100 overall with 88/100 on ingredient quality. The oxide product (Nature Made) manages just 52 on effectiveness and 37 on ingredient quality.
The reason is bioavailability. Magnesium oxide has roughly 4% absorption — most of it passes straight through your gut unused. Glycinate is chelated (bound to the amino acid glycine), which your intestines absorb much more efficiently. You also get fewer digestive side effects, since unabsorbed magnesium in the gut is what causes the laxative effect oxide is known for.
Oxide is cheap, which is why it's still everywhere. But cheap per pill means nothing if your body can't use it. Glycinate or citrate (avg 74.5/100) are both better choices.
Which form of magnesium is best for sleep, anxiety, or muscle cramps?
Glycinate for sleep and anxiety. Citrate for cramps. L-threonate for brain function. Each form has a different strength, and our scores back this up.
Sleep and anxiety → Glycinate. Averaging 74.3/100 across our database, with the best (Solgar Glycinate 400mg) hitting 80/100. Glycine, the amino acid it's bound to, acts as an inhibitory neurotransmitter — it calms your nervous system on its own. That's a two-for-one benefit you don't get from other forms. Thorne Bisglycinate (74/100) is another solid option at a lower dose.
Muscle cramps → Citrate. Averaging 74.5/100 overall with 85.0 on ingredient quality. Citrate absorbs well and is gentler on your wallet than glycinate. Solgar Citrate leads the pack at 77/100. If cramps are your main issue, this is the practical choice.
Brain function → L-Threonate. Life Extension Neuro-Mag scores 73/100. This is the only form shown to meaningfully raise magnesium levels in the brain by crossing the blood-brain barrier. It's pricier, but nothing else does what it does.
All-round absorption → Doctor's Best High Absorption tops our entire magnesium database at 82/100 overall (83 effectiveness, 88 ingredient quality) using chelated magnesium.
The one form to skip? Oxide at 53/100. Its 4% absorption rate makes it a poor choice no matter what you're taking it for.
Disclaimer: AIScored provides data-driven comparisons based on publicly available reviews. This is not medical advice. Affiliate links may earn us a commission at no extra cost to you.
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