Types of Magnesium: 8 Forms Ranked, Which Is Best (2026)
By Erin Rose Updated October 14, 2026 Sources
For most people, glycinate is the best type of magnesium; citrate is the lower-cost choice. Citrate costs less at list price and was absorbed better than oxide in small studies (NIH). Oxide was about 4% absorbed in one study. The 8 types: Glycinate, Citrate, Chloride, Malate, Taurate, L-Threonate, Oxide and Sulfate.
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Verified Supplement Data, updated :Of the 8 magnesium forms, glycinate is the default for most people. Oxide is 60% magnesium by weight but only about 4% absorbed, so the biggest label number is one of the worst forms. Keep supplemental magnesium under 350 mg a day.
The right form depends on whether your bottle lists elemental or compound milligrams — the 8-form table is below, and our magnesium dose calculator shows label doses by form: start with glycinate.
Which magnesium to buy, by form
Glycinate · our pick Nature Made Magnesium Glycinate 200mg 200 mg in 2 capsules, $0.73 a day at list price. Picked because it is on USP Verified; glycinate is gentle on the stomach.Score 8.0/10 among glycinate products · USP Verified
Buy on Amazon Nature Made Magnesium Glycinate 200mgGlycinate + oxide blend (powder) BulkSupplements Magnesium Glycinate Powder 300 mg per ¾ teaspoon, $0.19 for 300 mg at list price. Its label names glycinate and oxide, so it is not pure glycinate.Not scored · NSF/ANSI 173
Buy on Amazon BulkSupplements Magnesium Glycinate PowderCitrate · lowest cost per mg NOW Magnesium Citrate 200 mg $0.24 for 300 mg at list price. A serving (2 tablets) is 400 mg, over the limit; 1 tablet is 200 mg.Score 7.0/10 among citrate products · Not on a testing list
Buy on Amazon NOW Magnesium Citrate 200 mgGlycinate · big bottle of tablets Vitamin Shoppe Magnesium Glycinate 400 mg 135 tablets, 133 mg each. Take 1 or 2: the 3-tablet serving (400 mg) is over the limit. Not on a testing list.Not scored · Not on a testing list
Buy on Amazon Vitamin Shoppe Magnesium Glycinate 400 mgCitrate · tested, lower cost Nature Made Magnesium Citrate 250 mg 250 mg in 2 softgels, $0.47 for 300 mg at list price (our pick: $1.10).Score 9.0/10 among citrate products · USP Verified
Buy on Amazon Nature Made Magnesium Citrate 250 mgGlycinate · small capsules Thorne Magnesium Glycinate 120 mg a capsule, so you can set your own dose. $0.72 for 300 mg at list price.Score 6.5/10 among glycinate products · NSF/ANSI 173
Buy on Amazon Thorne Magnesium GlycinateGlycinate · lowest cost we score Nutricost Magnesium Glycinate 210 mg 210 mg in 3 capsules, $0.30 for 300 mg at list price. It scores above our pick on cost, but it is on no testing list.Score 8.5/10 among glycinate products · Not on a testing list
Buy on Amazon Nutricost Magnesium Glycinate 210 mgGlycinate · tablets Doctor's Best High Absorption Magnesium 200 mg in 2 tablets, $0.35 for 300 mg at list price. Its label allows 2 servings a day (400 mg), over the limit.Score 7.0/10 among glycinate products · Not on a testing list
Buy on Amazon Doctor's Best High Absorption MagnesiumGlycinate · large serving KAL Magnesium Glycinate 350 mg 350 mg in 4 capsules: one serving is the whole daily limit. No list price we could check.Not scored · Not on a testing list
Buy on Amazon KAL Magnesium Glycinate 350 mgOxide · for constipation Nature Made Magnesium Oxide 250 mg 250 mg a tablet, $0.071 for 300 mg at list price, the lowest cost per mg. About 4% was absorbed in one study, so it suits constipation better than raising your magnesium.Score 7.0/10 among oxide products · Not on a testing list
Buy on Amazon Nature Made Magnesium Oxide 250 mgDrink powder Natural Vitality Calm Magnesium Citrate Powder 350 mg in 2 tsp, $0.27 for 300 mg at list price. You mix it into a drink.Score 7.0/10 among citrate products · Not on a testing list
Buy on Amazon Natural Vitality Calm Magnesium Citrate PowderL-threonate · lowest cost of 3 Double Wood Magnesium L-Threonate 144 mg in 4 capsules, $2.15 for 300 mg at list price. Many times the cost per mg of glycinate.Score 5.5/10 among l-threonate products · Not on a testing list
Buy on Amazon Double Wood Magnesium L-ThreonateL-threonate (Magtein) Life Extension Neuro-Mag Magnesium L-Threonate 144 mg in 3 capsules, $2.19 for 300 mg at list price.Score 5.5/10 among l-threonate products · Not on a testing list
Buy on Amazon Life Extension Neuro-Mag Magnesium L-ThreonateL-threonate (Magtein) NOW Magtein Magnesium L-Threonate 144 mg in 3 capsules, $3.47 for 300 mg at list price.Score 4.5/10 among l-threonate products · Not on a testing list
Buy on Amazon NOW Magtein Magnesium L-ThreonateGummy Nature Made Magnesium Glycinate Gummies 100 mg 100 mg of magnesium in 2 gummies, $3.15 for 300 mg at list price. Much less magnesium than a capsule.Score 8.5/10 among gummy products · USP Verified
Buy on Amazon Nature Made Magnesium Glycinate Gummies 100 mgScores compare products within one form only. We track no chloride, malate, taurate or sulfate product. All 19 magnesium products we track, ranked.
Whatever the form, keep magnesium from supplements at or under 350 mg a day. Food does not count toward that limit (NIH). More mostly causes diarrhea.
Which form for which goal
No form has been proven best for a health goal; trials used whatever form the researchers chose. Here is what was tested.
| Goal | Form to choose | What the evidence says |
|---|---|---|
| Low intake, or a doctor said “take magnesium” | Glycinate or citrate | Citrate was absorbed better than oxide in small studies (NIH). No trial shows glycinate beats citrate. |
| Sleep | Glycinate (the 2025 trial’s form) | Small effect, weak evidence. A 2025 glycinate trial found a small benefit (Schuster 2025). Older trials of oxide, citrate and effervescent tablets cut time to fall asleep by about 17 minutes (Mah 2021); the citrate trial alone found no benefit over placebo (Nielsen 2010). |
| Constipation | Oxide (or citrate) | In 2 trials, 68% improved on oxide vs 19% on placebo (van der Schoot 2023). Citrate also loosens stools. |
| Leg cramps | No form shown to work for typical cramps | A Cochrane review found magnesium unlikely to help night cramps in older adults (Garrison 2020). In pregnancy, one trial of 300 mg of glycinate found fewer cramps (Supakatisant 2015). |
| Anxiety or stress | No form shown better | A review found hints of a benefit in people prone to anxiety but rated the studies poor (Boyle 2017). |
| Migraine | Only with a doctor | Neurology groups rate magnesium “probably effective,” but the doses used are above the limit, so NIH says to use it only with a doctor’s guidance. |
Glycinate or citrate? Neither has been shown to work better for general use: glycinate vs citrate, head to head.
All 8 Magnesium Forms at a Glance
Ranked for everyday use: what the absorption studies show, how each sits with the stomach, cost, and whether a product on a public testing list exists. It is not a strict absorption ranking, because no study has tested all 8 side by side.
| Form | Magnesium by weight | Absorption | Used for | Side effects | Cost |
|---|---|---|---|---|---|
| 1 Glycinatealso called Bisglycinate | ~14% | Not in the absorption studies NIH cites; about the same as oxide in one small trial (Schuette 1994) | Everyday magnesium when other forms upset your stomach | Better tolerated than oxide in one small trial (Schuette 1994); not on NIH’s list of forms most linked to diarrhea | Middle: $0.30 to $1.10 per 300 mg |
| 2 Citrate | ~16% | Absorbed better than oxide in small studies (NIH) | Everyday magnesium at a lower cost; also sold as a laxative | Can loosen stools at higher doses; not on NIH’s list of forms most linked to diarrhea | Low: $0.24 to $0.47 per 300 mg |
| 3 Chloride | ~12% (hexahydrate) | Absorbed better than oxide; equal to lactate and aspartate (Firoz 2001) | Oral tablets and topical oils or sprays | One of the forms most often linked to diarrhea (NIH) | Not priced (we track no chloride product) |
| 4 Malate | ~15% | Not in the absorption studies NIH cites | General use; marketed for fibromyalgia and energy | Not on NIH’s list of forms most linked to diarrhea | Not priced (we track no malate product) |
| 5 Taurate | ~9% | Not in the absorption studies NIH cites | Marketed for heart health | Not on NIH’s list of forms most linked to diarrhea | Not priced (we track no taurate product) |
| 6 L-Threonatealso called Magtein | ~7% (144 mg in 2,000 mg Magtein) | Not in the absorption studies NIH cites | Marketed for memory and focus | Not on NIH’s list of forms most linked to diarrhea | High: $2.15 to $3.47 per 300 mg |
| 7 Oxide | ~60% | About 4% absorbed in one study (Firoz 2001); less than citrate in small studies (NIH) | Constipation and heartburn; the cheapest magnesium per mg | One of the forms most often linked to diarrhea (NIH) | Very low: $0.071 per 300 mg |
| 8 Sulfatealso called Epsom salt | ~10% (heptahydrate) | Absorbed less well than citrate by mouth (NIH); skin absorption not shown | Bath soaks; given by IV in hospitals | A strong laxative when swallowed | Not priced (bath salt, not a supplement) |
Costs are per 300 mg of magnesium at each brand’s own list price, checked October 14, 2026. Open data (CC BY 4.0): download the data (JSON).
Why the Label Percentage Misleads You
The “magnesium by weight” share is not how much you absorb. Oxide is 60% magnesium by weight but was about 4% absorbed in one study; glycinate is about 14% magnesium. The magnesium is the same in every form. What changes is the carrier it is bound to, which affects how much gets in and how it sits with your stomach.
You do not need the math to read a label. The “Magnesium” line on the Supplement Facts panel is the magnesium itself (the elemental amount), not the weight of the whole compound (NIH). So “Magnesium 200 mg (as magnesium glycinate)” means 200 mg of magnesium. The trap is the front of the bottle, which often shows the whole compound.
| Item | Value (%) |
|---|---|
| Oxide | 60% |
| Citrate | 16% |
| Malate | 15% |
| Glycinate | 14% |
| Chloride | 12% |
| Sulfate | 10% |
| Taurate | 9% |
| L-Threonate | 7.2% |
L-threonate sits at the bottom for the opposite reason: a 2,000 mg serving of Magtein holds just 144 mg of magnesium. If you buy it, you are paying for the threonate, not for the magnesium.
What the shelf actually sells, and at what dose
We read 833 magnesium labels in NIH’s label database (out of 39,884 it lists on the market) and took the dose and the named form off each panel. Citrate is the most common form, named on 351 labels; oxide is on 244; glycinate or bisglycinate on 94. A label is counted once for each form of magnesium its Supplement Facts panel names, so a label with two forms counts under both.
| Main form | Middle serving | High 10% |
|---|---|---|
| Citrate | 250 mg | 500 mg |
| Oxide | 300 mg | 500 mg |
| Glycinate | 232.5 mg | 400 mg |
| Malate | 355 mg | 480 mg |
| Aspartate | 133 mg | 400 mg |
The dose runs opposite to the absorption. Oxide, the worst-absorbed form, has the highest middle dose on the shelf at 300 mg. Glycinate has 232.5 mg. Oxide is cheap and dense, so a big number on the front costs the maker little. So a 400 mg oxide tablet and a 200 mg glycinate capsule are not two doses of the same thing.
What this cannot tell you: how many bottles of each form are sold. It counts labels on the market, not purchases.
More on each form
1. Magnesium Glycinate (Bisglycinate)
Magnesium bound to glycine, an amino acid. In the one trial that compared it with oxide at the same dose (12 people), absorption was about the same and glycinate was better tolerated (Schuette 1994). Few trials tested glycinate itself: a 2025 sleep trial (Schuster 2025), a pregnancy leg-cramp trial (Supakatisant 2015) and that small absorption trial. No trial shows it works better than citrate.
2. Magnesium Citrate
Magnesium bound to citric acid. The most common form on labels. Liquid magnesium citrate sold at pharmacies is a bowel prep, a much bigger dose. Small studies found it absorbed better than oxide (NIH).
3. Magnesium Chloride
Sold as tablets, flakes and “magnesium oil” sprays. Whether magnesium sprayed on the skin raises body levels has not been shown. Absorbed as well as lactate and aspartate in one small study (Firoz 2001).
4. Magnesium Malate
Magnesium bound to malic acid, which the body uses to make energy. That is a reason it is sold, not a trial result. For fibromyalgia, magnesium with malic acid made little or no difference to pain (Ferreira 2019, PMID 31150373).
5. Magnesium Taurate
Magnesium bound to taurine, an amino acid. The case for pairing them comes from a 1996 hypothesis paper (McCarty, PMID 8692051). We found no human trial of magnesium taurate itself.
6. Magnesium L-Threonate (Magtein)
Developed to raise magnesium in the brain. The study that showed this was in rats (Slutsky 2010, PMID 20152124). A full serving gives only 144 mg of magnesium. The brain claim rests on rat work and two small human trials paid for by the maker (Liu 2016; Lopresti 2026), which found gains on memory and thinking tests.
7. Magnesium Oxide
The most magnesium per tablet and the lowest cost, which is why many bottles with big numbers use it. Most of it is not absorbed, and what stays in the gut draws in water. For constipation, 68% improved on oxide vs 19% on placebo in 2 trials (van der Schoot 2023).
8. Magnesium Sulfate (Epsom salt)
Epsom salt is for baths. Do not use it as a daily supplement. Hospital IV use is a medical treatment, not a supplement result.
Does the Label Agree With the Supplement Limit?
Often not. Of the 833 labels we read, 416 tell you to take more than 350 mg of magnesium a day if you follow the directions. Following the bottle is not the same as staying under the limit. Our earlier label-by-label check is open data (CC BY 4.0): download the label check (JSON).
Of the 19 magnesium products we track, 2 go over the limit in a single label serving (NOW Magnesium Citrate 200 mg, 400 mg; Vitamin Shoppe Magnesium Glycinate 400 mg, 400 mg), and 2 sit exactly at it. Some labels allow more than one serving a day: Thorne’s capsule is 120 mg, but its label allows up to 4 a day (480 mg), and Doctor’s Best’s says 2 tablets twice a day (400 mg). Over the limit, the usual result is loose stools, not danger, but you can avoid it: count the mg on the “Magnesium” line, times the servings you take.
Which Magnesium Is the Best Value?
Best value is the lowest cost for magnesium your body can use, not the cheapest bottle.
- Lowest cost of the well-absorbed forms: citrate. NOW Magnesium Citrate 200 mg works out to $0.24 per 300 mg of magnesium at list price. The lowest-cost pure glycinate is Nutricost Magnesium Glycinate 210 mg at $0.30.
- If citrate upsets your stomach: glycinate. Our pick, Nature Made Magnesium Glycinate 200mg, costs $1.10 per 300 mg. You pay more for a product on USP Verified. Nutricost costs less at list price ($0.30) but is on no testing list. Prices on Amazon differ.
- The false economy: oxide. Nature Made Magnesium Oxide 250 mg is $0.071 per 300 mg, the cheapest by far, but about 4% was absorbed in one study. It is a good buy for constipation, not for raising your magnesium.
- The premium: L-threonate. $2.15 to $3.47 per 300 mg, for a form whose brain claim rests on rat work and two small human trials paid for by the maker.
What every magnesium glycinate costs · cheapest glycinate per 200 mg · citrate picks compared.
Other, Less Common Forms
- Magnesium lactate and aspartate: absorbed better than oxide in small studies (NIH; Firoz 2001). Usually found in combination products.
- Magnesium carbonate: one of the forms most often linked to diarrhea (NIH). Mostly used as an antacid.
- Magnesium gluconate: also on NIH’s list of forms most linked to diarrhea.
- Magnesium hydroxide (milk of magnesia): a laxative and antacid, not a daily supplement.
- Magnesium orotate: bound to orotic acid. Expensive, and NIH says nothing about it.
Safety and Drug Interactions
Every form shares the same cautions.
- Too much at once. Too much magnesium from pills most often causes diarrhea, sometimes with nausea and stomach cramps. That is why the limit is set where it is (NIH).
- Kidney disease. If you have kidney disease, ask your doctor before you take magnesium. Weak kidneys cannot clear the extra, so it can build up (NIH).
- Antibiotics. Take tetracyclines (such as doxycycline) or quinolones (such as ciprofloxacin) at least 2 hours before or 4 to 6 hours after magnesium (NIH).
- Osteoporosis drugs. Bisphosphonates such as alendronate: take them at least 2 hours apart from magnesium (NIH).
- Water pills. Loop and thiazide diuretics make you lose more magnesium; potassium-sparing ones make you lose less (NIH). One large Dutch study found the link only for thiazides (Kieboom 2018).
- Heartburn pills. Heartburn pills (PPIs such as esomeprazole or lansoprazole), taken for a year or more, can lower magnesium. In about 1 in 4 of the cases FDA reviewed, supplements did not raise it and the PPI had to be stopped (NIH).
- Too much. Dangerous levels are rare. They have mostly come from very large doses of magnesium laxatives or antacids, usually more than 5,000 mg a day (NIH).
If you take prescription medicines, ask your pharmacist before starting magnesium. Magnesium side effects by form.
Frequently Asked Questions
What are the different types of magnesium?
The 8 common types, in our order for everyday use, are Glycinate, Citrate, Chloride, Malate, Taurate, L-Threonate, Oxide and Sulfate. Glycinate and citrate are the best everyday choices. Citrate was absorbed better than oxide in small studies (NIH) and costs less at list price; glycinate was better tolerated than oxide in one small trial (Schuette 1994). Chloride also absorbs well but is more often linked to diarrhea. Malate, taurate and L-threonate have little human data. Oxide is about 4% absorbed in one study and is sold mostly for constipation and heartburn. Sulfate (Epsom salt) is for baths.
What is the most absorbable form of magnesium?
In the small studies NIH cites, magnesium aspartate, citrate, lactate and chloride were absorbed more completely than oxide and sulfate. One study measured oxide at about 4% (Firoz 2001). A 2021 review of 14 studies found organic forms (such as citrate) generally absorbed better than inorganic ones (such as oxide), and that absorption depends on the dose (Pardo 2021). Glycinate was not in the studies NIH cites; in one small trial it was absorbed about as well as oxide (Schuette 1994).
Which type of magnesium has been studied for sleep?
Oxide, citrate and, more recently, glycinate. The three sleep trials in a 2021 review used magnesium oxide, magnesium citrate and effervescent magnesium tablets. Across 151 older adults with insomnia, people fell asleep about 17 minutes faster than on placebo, and total sleep time did not change significantly; the evidence was rated low quality (Mah 2021). One newer trial tested glycinate itself: in 155 adults who slept poorly, 250 mg of magnesium as bisglycinate for 4 weeks lowered insomnia scores a little more than placebo, a small effect (Schuster 2025). Magnesium and sleep.
Is magnesium bisglycinate the same as glycinate?
Yes, in practice. Bisglycinate is the full chemical name (magnesium bound to two glycines). Labels use both names for the same thing; Nature Made’s page says “biglycinate,” and NIH’s label database lists it as bisglycinate.
Does a powder, gummy or capsule absorb better?
No study we found compares them at the same dose. What differs is how much magnesium you get: gummies we score hold 70 to 100 mg a serving, far less than a capsule or a scoop of powder. Read the “Magnesium” line on the panel. Magnesium gummies.
Go Deeper
- Magnesium glycinate vs citrate: the two most-picked forms, head to head
- Citrate vs oxide · oxide vs glycinate · threonate vs glycinate
- How much magnesium to take: by age, and elemental vs compound weight
- Magnesium and sleep · amounts used in sleep studies · side effects by form
- How long magnesium takes to work · best time to take it
- Magnesium and anxiety: what the studies show (and how weak they are)
- Taking magnesium with vitamin D · signs of low magnesium · RBC magnesium test
- Magnesium gummies: how much magnesium they really hold
- Magnesium for muscle cramps: what the Cochrane review found
- Best magnesium supplement · best magnesium glycinate · third-party tested glycinate
- Thorne vs Doctor’s Best · Nature Made vs Doctor’s Best · glycinate 400 mg
- Magnesium for seniors · all magnesium guides
Sources
- NIH Office of Dietary Supplements. Magnesium fact sheet for health professionals (absorption by form, forms linked to diarrhea, upper limit, interactions; updated January 6, 2026, read October 14, 2026).
- Firoz M, Graber M. Bioavailability of US commercial magnesium preparations. Magnes Res. 2001. PubMed 11794633
- Pardo MR, et al. Bioavailability of magnesium food supplements: a systematic review. Nutrition. 2021. PubMed 34111673
- Schuette SA, et al. Bioavailability of magnesium diglycinate vs magnesium oxide in patients with ileal resection. JPEN J Parenter Enteral Nutr. 1994. PubMed 7815675
- Schuster J, et al. Magnesium bisglycinate supplementation in healthy adults reporting poor sleep: a randomized, placebo-controlled trial. Nat Sci Sleep. 2025. PubMed 40918053
- Mah J, Pitre T. Oral magnesium supplementation for insomnia in older adults. BMC Complement Med Ther. 2021. PubMed 33865376
- Nielsen FH, et al. Magnesium supplementation improves indicators of low magnesium status and inflammatory stress in adults older than 51 years with poor quality sleep. Magnes Res. 2010. PubMed 21199787
- van der Schoot A, et al. The effect of food, vitamin, or mineral supplements on chronic constipation in adults. Neurogastroenterol Motil. 2023. PubMed 37243443
- Ferreira I, et al. Magnesium and malic acid supplement for fibromyalgia. Medwave. 2019. PubMed 31150373
- McCarty MF. Complementary vascular-protective actions of magnesium and taurine: a rationale for magnesium taurate. Med Hypotheses. 1996. PubMed 8692051
- Slutsky I, et al. Enhancement of learning and memory by elevating brain magnesium. Neuron. 2010 (a study in rats). PubMed 20152124. Human trials: Liu G, et al. J Alzheimers Dis. 2016. PubMed 26519439; Lopresti AL, et al. 2026. PubMed 41601871 (both trials and their funding).
- Boyle NB, et al. The effects of magnesium supplementation on subjective anxiety and stress: a systematic review. Nutrients. 2017. PubMed 28445426
- Garrison SR, et al. Magnesium for skeletal muscle cramps. Cochrane Database Syst Rev. 2020. PubMed 32956536
- Supakatisant C, Phupong V. Oral magnesium for relief in pregnancy-induced leg cramps: a randomised controlled trial. Matern Child Nutr. 2015. PubMed 22909270
- Kieboom BCT, et al. Thiazide but not loop diuretics is associated with hypomagnesaemia in the general population. Pharmacoepidemiol Drug Saf. 2018. PubMed 30095199
- NIH Dietary Supplement Label Database: 833 magnesium labels read August 29, 2026; our analysis. Prices: each brand’s own list price, checked October 14, 2026; we quote no Amazon prices.
This page is for information. It is not medical advice.