Pure Encapsulations vs Thorne vs Doctor's Best Magnesium Glycinate Compared
Published Updated Ben Law
Reviewed by Sarah Law, Dip CNM, Naturopathic Nutritionist
Pure Encapsulations vs Thorne vs Doctor's Best magnesium glycinate: Pure Encapsulations and Thorne capsules both give 120 mg of elemental magnesium per capsule for about 21 to 25 US cents per 100 mg; Thorne's Magnesium Bisglycinate powder gives 200 mg per scoop and is NSF Certified for Sport; Doctor's Best gives 200 mg per two tablets from a lysinate glycinate chelate and is the cheapest per milligram. Love Life Supplements Magnesium Glycinate gives the largest single serving of pure, unbuffered glycinate, 303 mg per four capsules, with Eurofins measuring 302 mg in the current batch. Choose Thorne's powder for tested sport, Doctor's Best for lowest cost, and ours for the full dose with published lab results.
Our figures come from our own label and lab report. Magnesium Glycinate supplies 2,750 mg of magnesium bisglycinate per four-capsule serving, of which 303 mg is elemental magnesium (81% of the UK NRV), with no magnesium oxide buffering and nothing else in the capsule except the vegetable shell. Batch L1026118 was tested by Eurofins in Hamburg on 6 July 2026 and measured 302 mg per four capsules, with lead at 0.10 mg/kg against an EU limit of 3.0. A 240-capsule tub is a 60-day supply at £37.95 on our UK store and $51.47 on our US store. It won an Award of Excellence at the Nourish Awards 2026, is rated 4.8 out of 5 from 295 customer ratings, and is covered by our 60-day money-back guarantee.
Magnesium Glycinate: 303 mg elemental magnesium per serving, unbuffered bisglycinate, UK-made, every batch third-party tested.
View product- Pure Encapsulations Magnesium (glycinate): 120 mg per capsule, cellulose capsule plus ascorbyl palmitate, GFCO-certified gluten free. $27 for 90 ($0.25 per 100 mg).
- Thorne Magnesium Glycinate (capsule): 120 mg per capsule, with silicon dioxide and MCT oil. $26 for 90 ($0.24 per 100 mg).
- Thorne Magnesium Bisglycinate (powder): 200 mg per scoop, NSF Certified for Sport. $52 for 60 servings ($0.43 per 100 mg).
- Doctor's Best High Absorption Magnesium: 200 mg per two tablets from Albion lysinate glycinate chelate. $13.99 for 120 ($0.12 per 100 mg), the cheapest per milligram.
- Love Life Supplements Magnesium Glycinate: 303 mg per four capsules, pure unbuffered bisglycinate, Eurofins-verified batch. £37.95 or $51.47 for 240 (20.9p or $0.28 per 100 mg).
Pure Encapsulations vs Thorne vs Doctor's Best: the comparison table
The biggest differences between these products are elemental magnesium per serving, what else is in the capsule or tablet, and price per 100 mg of magnesium, not the magnesium itself, which is bound to glycine in every case (with lysine as well in Doctor's Best). Every competitor figure below was read from the supplement facts panel and ingredient list on the brand's own product page on 16 October 2026. Prices are one-off US list prices on each brand's own store; price per 100 mg is our own calculation.
| Product | Form on the label | Elemental magnesium per serving | Units per serving | Other ingredients | Certification named on page | List price | Price per 100 mg magnesium |
|---|---|---|---|---|---|---|---|
| Pure Encapsulations Magnesium (glycinate) | Magnesium glycinate | 120 mg | 1 capsule | Vegetarian capsule (cellulose, water), ascorbyl palmitate | GFCO gluten free; non-GMO; vegan | $27.00 / 90; $46.50 / 180 | $0.25 (90); $0.22 (180) |
| Thorne Magnesium Glycinate (capsule) | Magnesium glycinate | 120 mg | 1 capsule | Hypromellose capsule, silicon dioxide, MCT oil | Gluten, dairy and soy free | $26 / 90; $46 / 180 | $0.24 (90); $0.21 (180) |
| Thorne Magnesium Bisglycinate (powder) | Magnesium bisglycinate | 200 mg | 1 scoop | Citric acid, monk fruit concentrate | NSF Certified for Sport | $52 / 60 servings | $0.43 |
| Doctor's Best High Absorption Magnesium | Magnesium lysinate glycinate chelate (Albion TRAACS) | 200 mg | 2 tablets | Microcrystalline cellulose, croscarmellose sodium, magnesium stearate, stearic acid, hydroxypropyl cellulose, silicon dioxide, hypromellose | Albion TRAACS; non-GMO; vegan | $13.99 / 120; $23.99 / 240 | $0.12 (120); $0.10 (240) |
| Love Life Supplements Magnesium Glycinate | Magnesium glycinate (bisglycinate), unbuffered | 303 mg (Eurofins measured 302 mg) | 4 capsules | Vegetable capsule (hypromellose) only | Made in the UK under GMP; vegan; batch lab report published | £37.95 or $51.47 / 240 | 20.9p or $0.28 |
Sources: pureforyou.com (Pure Encapsulations' official store, which pureencapsulations.com now directs to), thorne.com and doctorsbest.com product pages, read 16 October 2026; our own label and Eurofins report AR-733-2026-00087324-03. Price per 100 mg = list price divided by (servings x elemental mg per serving / 100). Larger packs and subscriptions cost less per milligram on every brand, including ours (10% off a first subscription order, 15% from the second). Pure Encapsulations also sells 30 and 360-capsule sizes ($0.35 and $0.20 per 100 mg). Doctor's Best sells other magnesium formats we did not compare. Prices change; check each brand's site before you buy.
Which magnesium glycinate has the most magnesium per serving?
Love Life Supplements Magnesium Glycinate has the most elemental magnesium per serving of the products compared, 303 mg per four capsules, against 200 mg per serving for Thorne's powder and Doctor's Best and 120 mg per capsule for Pure Encapsulations and Thorne's capsule. Per capsule, though, the 120 mg products carry more: our capsules hold 75.75 mg each, because bisglycinate is only about 14% magnesium by weight and we do not blend in denser forms such as magnesium oxide to shrink the capsule count.
That trade-off is the main thing to understand about any glycinate label. Magnesium oxide is around 60% magnesium by weight but was absorbed at roughly 4% in a human study of US commercial preparations [1], while chelated and organic forms performed better in head-to-head studies [2] [3]. A "buffered" glycinate mixes the two to raise the milligrams per capsule. None of the four competitor pages we read lists magnesium oxide, and our label states "pure chelate, unbuffered". Our magnesium glycinate vs citrate vs oxide guide covers the absorption research in more detail.
How many capsules for 300 mg?
| Product | Units for about 300 mg elemental | Magnesium delivered | Cost of that amount (US list price, larger pack) |
|---|---|---|---|
| Pure Encapsulations (120 mg capsule) | 2.5 capsules | 300 mg | $0.65 |
| Thorne capsule (120 mg) | 2.5 capsules | 300 mg | $0.64 |
| Thorne powder (200 mg scoop) | 1.5 scoops | 300 mg | $1.30 |
| Doctor's Best (100 mg tablet) | 3 tablets | 300 mg | $0.30 |
| Love Life Supplements (75.75 mg capsule) | 4 capsules | 303 mg | $0.86 (63p UK) |
Our calculation from the panel figures and list prices above (Pure Encapsulations 180-count, Thorne capsule 180-count, Doctor's Best 240-count). Half capsules are shown for comparison only; in practice you would take two or three.
"When I compare magnesium glycinate brands, I convert everything to elemental magnesium per day and price per 100 mg. Capsule counts and front-of-pack numbers can make products look more different than they really are."
Sarah Law, Naturopathic Nutritionist | Optimised Female
How much magnesium do you need? UK and US figures
Most adults need roughly 270 to 420 mg of magnesium a day from all sources, depending on sex and which country's figures you use, and supplements are usually taken at 100 to 350 mg to top up food. The two systems are set differently, so here they are side by side.
| Reference | Figure | Source |
|---|---|---|
| UK labelling reference (NRV) | 375 mg a day | Retained Regulation 1169/2011, Annex XIII [8] |
| NHS daily need | 300 mg (men 19 to 64), 270 mg (women 19 to 64) | NHS [7] |
| NHS supplement guidance | 400 mg or less a day from supplements is unlikely to cause harm | NHS [7] |
| US RDA | 400 to 420 mg (men), 310 to 320 mg (women) | NIH Office of Dietary Supplements [6] |
| US upper limit (supplements only) | 350 mg a day for adults | NIH Office of Dietary Supplements [6] |
Two practical points follow. First, a 303 mg serving sits under both the NIH supplemental upper limit and the NHS 400 mg guidance. Second, the top of some US label ranges goes above the NIH figure: four 120 mg capsules is 480 mg, and Doctor's Best directions of two tablets twice a day give 400 mg. The upper limit is set because larger supplemental doses can loosen stools; most people take one to three 120 mg capsules. Our guide to how much magnesium glycinate per day converts compound weights to elemental milligrams for any label.
What magnesium does is set out in the authorised health claims on the GB register [9]: it contributes to the reduction of tiredness and fatigue, to normal muscle function, to normal psychological function and to the normal functioning of the nervous system. Every product in this comparison supplies enough magnesium per serving to qualify for those claims, so the choice comes down to dose, excipients, testing and price.
Which magnesium glycinate is third-party tested?
All four brands describe quality controls, but they publish different things. Thorne's Magnesium Bisglycinate powder carries NSF Certified for Sport, an independent programme that tests for substances banned in sport and checks label claims; the Thorne glycinate capsule page did not show that mark when we checked. Pure Encapsulations' page names GFCO gluten-free certification and lists what the capsule is free from. Doctor's Best names Albion TRAACS, which is the branded chelate supplier, along with non-GMO and vegan marks. We did not find a batch-specific lab result on any of the three competitor product pages we read.
We publish ours. The full method is here; the current batch reads as follows.
| Test (batch L1026118, Eurofins, 6 July 2026) | Result | Reference |
|---|---|---|
| Elemental magnesium per 4 capsules | 302 mg (measured twice) | 303 mg on the label |
| Lead | 0.10 mg/kg | EU limit 3.0 mg/kg |
| Cadmium | Less than 0.010 mg/kg | EU limit 1.0 mg/kg |
| Mercury | Less than 0.005 mg/kg | EU limit 0.10 mg/kg |
| Arsenic | Less than 0.10 mg/kg | No EU limit set |
| Salmonella / E. coli | Not detected / less than 10 cfu/g | Pass |
Eurofins report AR-733-2026-00087324-03. Elemental magnesium by ICP-OES in duplicate; heavy metals by ICP-MS (DIN EN 15763); contaminant and microbiology testing accredited to ISO/IEC 17025. The report and earlier batches' Certificates of Analysis are linked on the product page. If you compete in tested sport, note that our product does not carry NSF Certified for Sport or Informed Sport.
"For clients who compete in tested sport, I point them to a product with a sport certification such as NSF Certified for Sport. For everyone else, I look for a batch-specific lab result I can read, because a quality statement on its own tells me very little."
Sarah Law, Naturopathic Nutritionist | Optimised Female
Which magnesium glycinate is cheapest?
Doctor's Best is the cheapest per milligram of the products we compared, at 10 to 12 US cents per 100 mg of magnesium. Pure Encapsulations and Thorne capsules sit at 20 to 25 cents in their larger packs, ours at 28 cents in the US (20.9p in the UK), and Thorne's NSF-certified powder at 43 cents.
Price per milligram is only one line of the comparison. What you are paying for with the more expensive options is either a sport certification (Thorne's powder), a short excipient list (Pure Encapsulations and ours), or a large single dose with batch results you can read (ours). If your priority is the lowest cost for magnesium bound to glycine and you do not mind tablet excipients or a lysine-glycine chelate, Doctor's Best is the value pick. On our UK store, subscribing takes 10% off the first order and 15% off every order after, which brings a tub to £32.26 from the second delivery.
Pure Encapsulations, Thorne, Doctor's Best or Love Life Supplements: which should you choose?
Choose by the one thing that matters most to you. Every product here supplies magnesium bound to glycine at a useful dose; they differ in what surrounds it.
Pick by priority
Love Life Supplements Magnesium Glycinate: 303 mg per serving, unbuffered, Eurofins measured 302 mg. UK and US stores.
Thorne Magnesium Bisglycinate powder, the one product here with NSF Certified for Sport.
Pure Encapsulations Magnesium (glycinate): 120 mg per capsule with a cellulose shell and ascorbyl palmitate only.
Doctor's Best High Absorption Magnesium: 200 mg per two tablets, from 10 cents per 100 mg.
Nourish Awards 2026, Award of Excellence: "a strong elemental dose and exceptional batch testing." Magnesium Glycinate, 60-day supply, 60-day money-back guarantee.
View productIf you want more than one form of magnesium in a single product, our best magnesium supplement guide compares multi-form complexes, and our magnesium glycinate buyer's guide covers the label checks that apply to any glycinate brand.
What does the research say about magnesium glycinate?
The research on glycinate as a form is smaller than the marketing suggests, and none of it is brand-specific. A 1994 study found magnesium diglycinate was absorbed better than magnesium oxide in people with impaired intestinal absorption [3], and a 2003 randomised study found organic forms (citrate and an amino-acid chelate) more bioavailable than oxide [2]. More recently, a 2025 randomised, placebo-controlled trial gave 250 mg of magnesium from bisglycinate to healthy adults reporting poor sleep and found a small improvement on a sleep questionnaire against placebo [4]. These are reasons to prefer a well-absorbed form over oxide; they do not show that one brand of glycinate outperforms another. The what happens if you take magnesium glycinate every day guide covers daily use.
How we compared these products
We read each competitor's supplement facts panel, ingredient list, directions and certification marks from its own product page on 16 October 2026 (Pure Encapsulations via pureforyou.com, its official store). We did not use retailer listings or review sites, and where a page title disagreed with the panel (Doctor's Best titles say 100 mg per tablet, the serving is two tablets) we used the panel. We could not read a GBP price on Pure Encapsulations' UK site on the day, so all competitor prices are US list prices. We have not lab-tested the competitor products and make no claim about their contents beyond their own labels.
Magnesium glycinate brands: frequently asked questions
Is Pure Encapsulations or Thorne magnesium glycinate better?
On the label they are close. Pure Encapsulations Magnesium (glycinate) and Thorne Magnesium Glycinate capsules both give 120 mg of elemental magnesium per capsule and cost about the same per 100 mg in the US (about 21 to 25 cents). Pure Encapsulations lists only a cellulose capsule and ascorbyl palmitate; Thorne's capsule adds silicon dioxide and MCT oil. Thorne's Magnesium Bisglycinate powder is the one of the three that carries NSF Certified for Sport, which matters if you compete in tested sport.
How many Pure Encapsulations magnesium glycinate capsules should I take?
Each Pure Encapsulations capsule provides 120 mg of elemental magnesium and the label suggests 1 to 4 capsules a day. Two capsules give 240 mg and three give 360 mg. The NIH sets an upper limit of 350 mg a day for magnesium from supplements, and the NHS says 400 mg or less a day from supplements is unlikely to cause harm, so most adults stay at one to three.
Is Thorne magnesium glycinate good?
Thorne makes two glycinate products. The capsule gives 120 mg of elemental magnesium per capsule for 26 US dollars per 90; the Magnesium Bisglycinate powder gives 200 mg per scoop for 52 US dollars per 60 servings, with citric acid and monk fruit for flavour, and is NSF Certified for Sport. Both are a reasonable choice; the powder costs more per milligram but is the only one of the brands compared here with a sport certification.
Is Doctor's Best magnesium the same as magnesium glycinate?
Not exactly. Doctor's Best High Absorption Magnesium uses Albion's magnesium lysinate glycinate chelate, where the magnesium is bound to both lysine and glycine, so it is a related chelate rather than a pure glycinate. Two tablets supply 200 mg of elemental magnesium from 2,000 mg of the chelate, alongside tableting excipients such as microcrystalline cellulose and magnesium stearate. It was the cheapest per 100 mg of magnesium in our comparison.
Which magnesium glycinate brand is best?
It depends on what you value. For the most elemental magnesium from a single unbuffered glycinate in one serving, with independent lab results for the batch, Love Life Supplements Magnesium Glycinate gives 303 mg per four capsules (Eurofins measured 302 mg). For a sport certification, Thorne's powder is NSF Certified for Sport. For a short excipient list in a flexible 120 mg dose, Pure Encapsulations. For the lowest price per milligram, Doctor's Best.
Can I buy Thorne and Pure Encapsulations in the UK?
Pure Encapsulations runs an official UK website, and both brands are sold through UK retailers, but UK prices vary by seller, so this comparison uses each brand's own US list price. Love Life Supplements Magnesium Glycinate is made in the UK and sold on our UK store at 37.95 pounds and on our US store at 51.47 US dollars for 240 capsules.
About the Reviewer: Sarah Law, Dip CNM
Sarah Law is a Certified Naturopathic Nutritionist and Functional Practitioner specialising in hormonal health, gut health, and evidence-based nutrition. She holds a Diploma in Naturopathic Nutrition from the College of Naturopathic Medicine (CNM, London) and is a Certified Functional Health Coach. Sarah combines naturopathic principles with modern functional nutrition science to help her clients make informed health decisions.
About the Author: Ben Law
Ben Law is the founder of Love Life Supplements and host of the Optimised Health Show. He is a qualified Advanced Dietary Supplement Advisor and Primal Blueprint Certified Expert, and has spent 14 years building transparent, research-led formulations manufactured to GMP and BRC standards. He wrote this comparison from each brand's published label and from our own label and batch data.
Pure Encapsulations, Thorne and Doctor's Best are trademarks of their respective owners and are not affiliated with Love Life Supplements. Learn more about Ben.
References
- Firoz M, Graber M. Bioavailability of US commercial magnesium preparations. Magnes Res. 2001;14(4):257-262. PubMed
- Walker AF, Marakis G, Christie S, Byng M. Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study. Magnes Res. 2003;16(3):183-191. PubMed
- Schuette SA, Lashner BA, Janghorbani M. Bioavailability of magnesium diglycinate vs magnesium oxide in patients with ileal resection. JPEN J Parenter Enteral Nutr. 1994;18(5):430-435. PubMed
- Schuster J, et al. Magnesium bisglycinate supplementation in healthy adults reporting poor sleep: a randomized, placebo-controlled trial. Nat Sci Sleep. 2025. PubMed
- Love Life Supplements. Eurofins report AR-733-2026-00087324-03, Magnesium Glycinate batch L1026118, 6 July 2026 (linked on the product page). Product page
- NIH Office of Dietary Supplements. Magnesium: fact sheet for health professionals. NIH ODS
- NHS. Vitamins and minerals: others (magnesium). NHS
- Regulation (EU) No 1169/2011 on the provision of food information to consumers, Annex XIII (reference intakes), as retained in GB law. legislation.gov.uk
- Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register. GOV.UK
- Pure Encapsulations. Magnesium (glycinate), official store product page (read 16 October 2026). pureforyou.com
- Thorne. Magnesium Bisglycinate and Magnesium Glycinate product pages (read 16 October 2026). thorne.com
- Doctor's Best. High Absorption Magnesium, 120 tablets, product page (read 16 October 2026). doctorsbest.com