~ means approximate; — means no published value in this record. Customer ratings are the named publisher’s snapshot and may include multiple sizes or earlier formulas. The Supplement Explained Score is our source-reviewed editorial assessment out of 25, separate from customer stars. Compare the five criteria and the same intended use; the total is not a clinical ranking. Prices are dated USD offer snapshots; cost uses the reviewed pack and label serving.
Label clarity: 5/5
Evidence transfer: 4/5
Safety fit: 4/5
Quality proof: 3/5
Value fit: 4/5
NOW Magnesium Glycinate Tablets provide 100 mg elemental magnesium per tablet, or 200 mg per two-tablet serving. The 90-count bottle has 45 servings; the 180-count bottle has 90. These are coated tablets, not NOW’s separate BioPerine capsules. They are worth comparing if you prefer counted units to a powder, but tablet size and the complete ingredient list still matter.
Check medicines, kidney function and your other magnesium sources before use. The adult supplemental upper limit is 350 mg daily unless a healthcare professional directs otherwise; a label’s maximum directions are not a personal dosing recommendation.
The two bottle sizes use the same declared 200 mg serving, but contain different numbers of servings. NOW lists the following identities. [1]
Bottle
Identity
Declared magnesium and servings
90 tablets
SKU 1286; UPC 733739012869
100 mg per tablet; 200 mg per two tablets; 45 servings
180 tablets
SKU 1289; UPC 733739012890
100 mg per tablet; 200 mg per two tablets; 90 servings
The magnesium source is magnesium bisglycinate (Albion). Other ingredients include citric acid, hydroxypropyl cellulose, vegetable-source stearic acid, silicon dioxide and a vegetarian coating. The coating lists hypromellose, stearic acid, sunflower lecithin, triethyl citrate and sunflower oil. This is not a magnesium-only powder. [1]
NOW also sells a separate “Magnesium Glycinate with BioPerine” capsule product. Do not use its capsule count, ingredients or label serving to evaluate these tablets.
How can you check whether the tablets are too large?
NOW’s product gallery includes a tablet size chart for the 180-count product. Check the manufacturer’s chart before ordering if swallowing is a concern. A two-tablet serving tells you the number of units, not whether their size will suit you.
Two tablets make the labeled serving. That may be convenient for counting, but it still means swallowing two units rather than drinking a powder. Do not assume a tablet is suitable for you because a reviewer calls it “easy to swallow,” and do not crush or alter it without checking with the manufacturer or a pharmacist.
What does the 180-tablet bottle cost per serving?
HerbsPro’s matched 180-tablet record was $19.98 on October 7, 2026. That is approximately $0.222 per two-tablet serving or $0.111 per 100 mg magnesium. NOW’s own 90- and 180-tablet sale listings are separate offers, not prices for this HerbsPro button. [2][1]
Seller and pack
Checked price
Cost per 200 mg serving
Cost per 100 mg
HerbsPro, 180 tablets
$19.98
$0.222; 90 servings
$0.111
NOW, 90 tablets, sale
$13.49
$0.300; 45 servings
$0.150
NOW, 180 tablets, sale
$23.99
$0.267; 90 servings
$0.133
All three price snapshots exclude shipping, tax and additional discounts. Promotions and availability can change. These calculations compare declared elemental magnesium, not absorbed magnesium or a guaranteed effective dose.
What does the quality information establish?
NOW identifies the ingredient source and lists GMP and dietary attributes on the official page. Those are useful checks, but facility information is not the same as a public test report for your bottle’s lot, and an ingredient trademark is not a clinical trial of this finished product.
We have not established an exact NSF Certified for Sport listing for these tablets or independently tested their contents. If that certification is required, compare a product with its own verifiable record rather than assuming all magnesium glycinate products are equivalent. The NOW Foods brand review separates facility and product-level evidence.
Does glycinate mean no diarrhea or guaranteed better sleep?
No. The product’s form does not guarantee either. Magnesium supplements can cause diarrhea, nausea or abdominal cramping, and adding more may not address the reason for poor sleep or cramps. [3]
Two tablets provide 200 mg; four provide 400 mg. The manufacturer’s “1 to 2 times daily” directions therefore reach an amount above the US 350 mg adult upper limit for supplements and medicines. That limit excludes food magnesium and can be exceeded under professional guidance, but the maximum label direction should not become a general recommendation here.
If swallowing is the issue, compare magnesium powders, including different sweeteners, scoop amounts and testing records. If you are comparing capsule burden rather than powder, use Solaray vs NOW magnesium glycinate.
Thorne’s powder provides a different drink format with monk fruit and exact sport-directory records to check. It is not the same product, and its certification does not cover NOW tablets.
FAQ
Is NOW Magnesium Glycinate 100 mg or 200 mg?
It is 100 mg elemental magnesium per tablet. The label serving is two tablets, providing 200 mg.
How many servings are in 180 tablets?
There are 90 two-tablet servings. The 90-tablet bottle has 45 servings.
Are these the BioPerine capsules?
No. NOW’s Magnesium Glycinate with BioPerine capsules are a separate product with their own ingredient list and serving instructions.
How do I check the tablet size?
Open NOW’s official product gallery and its 180-tablet size chart before buying. We have not measured a tablet or verified a numerical dimension from that image.
Five equally weighted criteria, with a product-specific reason for every point. This is a buying-decision assessment, separate from customer stars and personal medical suitability.
Two tablets provide 200 mg elemental magnesium; glycinate evidence does not establish a guaranteed sleep result for this bottle.
Safety fit 4/5
This amount is below the supplemental UL; count other magnesium and review renal function and medicine timing.
Quality proof 3/5
Albion ingredient and GMP manufacturing claims do not independently verify the purchased finished-tablet lot.
Value fit 4/5
The $0.22 200 mg serving snapshot and 90-serving pack compare closely with Doctor's Best's $0.23 snapshot; neither is declared market-wide cheapest.
Review basis: Published labels, manufacturer/retailer information, clinical sources and exact-product quality records where available. We did not buy, personally use or laboratory-test this product for this assessment.
Product labels and independent directory records identify a formula or testing scope. Clinical references concern ingredients or studied regimens unless the explanation explicitly matches the finished formula.
