Independent supplement ratingsUS and Canada · Updated weekly
A ratings desk for a category that has spent thirty years grading its own homework.
A ratings desk for a category that has spent thirty years grading its own homework.
One calculation across all 27 products in our rankings. The spread runs to nineteen-fold, and for six of them the sum cannot be done at all.
The short version: we took every product in our rankings and divided its price per serving by the amount of active ingredient in that serving. Inside a single category the price of one gram of the same substance varies by up to nineteen times. And for six products, the calculation cannot be done at all — which turned out to be the more useful finding.
One line, and you can check it on any product in your cupboard:
price per serving ÷ grams of active ingredient per serving = cost per gram.
Price per serving, not the price of the tub, because tub sizes are chosen to make comparison hard. Active ingredient, not net weight, because a 1,000 mg capsule of magnesium oxide contains about 600 mg of magnesium and the rest is oxide. All prices are the ones on our product pages, checked in August 2026; formulas and prices both move, so treat the ratios as the point rather than the decimals.
Priced per gram of elemental magnesium — the figure that matters, and the one most labels bury.
| Product | Per serving | Elemental Mg | Cost per gram |
|---|---|---|---|
| Nature Made Magnesium Oxide | $0.05 | 250 mg | $0.20 |
| NOW Foods Magnesium Citrate | $0.14 | 400 mg | $0.35 |
| Doctor's Best High Absorption | $0.11 | 200 mg | $0.55 |
| Pure Encapsulations Glycinate | $0.38 | 120 mg | $3.17 |
| Thorne Magnesium Bisglycinate | $0.78 | 200 mg | $3.90 |
| BiOptimizers Magnesium Breakthrough | $1.30 | per-form dose not disclosed | |
Nineteen and a half times, for the same mineral. Before anyone buys the cheapest column: this is exactly why our magnesium ranking does not sort on price. Oxide is cheap because the body absorbs comparatively little of it, so a gram on the label is not a gram delivered. The forms guide works through that arithmetic.
The more interesting rows are the middle ones. Doctor's Best delivers a well-absorbed chelate at $0.55 a gram; Thorne delivers the same form, at the same 200 mg, for seven times that. Thorne carries NSF Certified for Sport testing and Doctor's Best does not, which is worth something to a drug-tested athlete and close to nothing to everyone else.
An electrolyte drink is bought for sodium replacement, so sodium is what we priced.
| Product | Per serving | Sodium | Cost per gram |
|---|---|---|---|
| LMNT Recharge | $1.50 | 1,000 mg | $1.50 |
| Nuun Sport | $0.70 | 300 mg | $2.33 |
| Liquid I.V. Hydration Multiplier | $1.20 | 500 mg | $2.40 |
| DripDrop ORS | $1.00 | 330 mg | $3.03 |
| Ultima Replenisher | $0.55 | 55 mg | $10.00 |
LMNT is the most expensive stick on the list and the cheapest sodium on it, by a distance. That is the whole trick of the category: the product that looks premium per serving is the one actually carrying the dose.
Ultima at ten dollars a gram deserves a fair hearing rather than a headline. It is not built as a sodium product — it leads on magnesium and potassium, and it is sugar-free and pleasant to drink. If you are replacing what a hard, sweaty hour costs you, it is the wrong tool. If you want something in water on a normal day, the number above is not the number to judge it by. Our electrolyte calculator will tell you which case you are in.
Priced per gram of standardized extract.
| Product | Per serving | Extract | Cost per gram |
|---|---|---|---|
| NOW Foods Ashwagandha Extract | $0.16 | 450 mg | $0.36 |
| Nootropics Depot KSM-66 | $0.30 | 600 mg | $0.50 |
| Gaia Herbs Ashwagandha Root | $0.50 | 350 mg | $1.43 |
| Goli Ashwagandha Gummies | $0.50 | 300 mg | $1.67 |
| Nature Made KSM-66 + Reishi | $0.50 | KSM-66 sits inside a blend | |
Under five-fold, which makes this the best-behaved category we rate. The gummy costs about four and a half times the capsule per gram, and holds half the dose per serving — the premium is for the format, and plenty of people will pay it knowingly, because a gummy you take beats a capsule you skip.
The ingredient with human evidence for blood flow in this category is L-citrulline, so that is what we priced.
| Product | Per serving | L-citrulline | Cost per gram |
|---|---|---|---|
| Nutricost L-Citrulline Malate | $0.18 | ~2,000 mg | $0.09 |
| Doctor's Best L-Citrulline Powder | $0.33 | 3,000 mg | $0.11 |
| NOW L-Citrulline Pure Powder | $0.27 | 1,500 mg | $0.18 |
| NOW Arginine & Citrulline | $0.14 | 250 mg | $0.56 |
Nine cents a gram at one end, fifty-six at the other, for the identical amino acid. The capsule product is the cheapest serving on the table and the dearest gram on it — which is the whole reason we stopped comparing servings. The other two products we rate here are priced on different actives: maca root works out at about twelve cents a gram, and the ginseng extract at sixty-eight.
What is missing from this table is the rest of the category. Most of what is sold for this purpose arrives as a proprietary blend, and a blend has no denominator — the amount of each ingredient is undisclosed by design, so there is no gram to divide by. We do not rate those products at all, for the reason this article exists. The full reasoning is in the category ranking.
Six products, and not one produces an honest cost per gram.
Nugenix Total-T and Six Star Testosterone Booster hide their per-ingredient amounts inside proprietary blends, so there is no denominator to divide by. That is the point of a blend.
Transparent Labs Vitality, Prime Male and TestoPrime do disclose every dose — credit where it is due — but they spread the money across six or eight actives, so "cost per gram" depends entirely on which one you decide you are buying.
TestoFuel is the one product with a single headline number: 2,300 mg of D-aspartic acid at $2.16 a serving, or $0.94 a gram. It is a clean figure for an ingredient whose better-controlled trials mostly failed to reproduce any testosterone benefit in trained men. You can price it precisely. It is the precision that stings.
A category where the arithmetic is impossible for five products out of six is telling you something before you read a single review. The ranking and the Label Dose Checker both start from that.
Cost per gram is one input, not a verdict, and using it alone would produce a worse shopping list than using nothing.
Which is why it carries 25% of the score in our method and not 100%.
Run the calculation on whatever you are about to buy. You need two numbers from the label — the serving size and the amount of the ingredient you are actually paying for — and the price. If the second number is missing because it sits inside a blend, that is your answer.
Then check the dose against the research rather than against the price: the Label Dose Checker lines any product up against the amount used in published trials, and the rankings show where each one lands once every input is counted.
Prices checked August 2026 from the retailer listings linked on each product page. Prices change; the ratios are the durable part.