How we calculate
Every number on this site can be recalculated. Here is the formula, the data source, and what we deliberately do not judge.
1. Elemental active, not compound mass
The label states the amount of the compound, not of the nutrient. 500 mg of magnesium citrate contain about 81 mg of magnesium; 500 mg of magnesium oxide about 302 mg. We multiply the declared amount by the nutrient's mass share of the compound. If the label already states the elemental content, we use it unchanged.
2. Price per serving
Package price plus shipping, divided by the servings per package as stated on the label. Shipping belongs in the calculation because a low product price with high shipping can cost more than the reverse.
3. Price per gram of active
Price per serving divided by the elemental amount per serving. Only this figure makes capsules, powders and drops comparable.
4. What we do not judge
We make no claims about effect, tolerability or bioavailability, and we give no intake recommendation. We compare content, amount, dosage form, price and transparency.
Elemental fractions of every compound on file
Every fraction is calculated from the chemical formula rather than typed in. The “500 mg →” column shows how much of the nutrient 500 mg of the substance delivers.
Magnesium
| Compound | Share of pure active | 500 mg → | Source |
|---|---|---|---|
| Magnesium oxide | 60.3% | 302 mg | MgO, M = 40.304 g/mol |
| Magnesium hydroxide | 41.7% | 208 mg | Mg(OH)2, M = 58.319 g/mol |
| Magnesium carbonate | 28.8% | 144 mg | MgCO3, M = 84.313 g/mol |
| Magnesium chloride | 25.5% | 128 mg | MgCl2, M = 95.205 g/mol |
| Magnesium sulfate | 20.2% | 101 mg | MgSO4, M = 120.361 g/mol |
| Magnesium citrate | 16.2% | 80.8 mg | Mg3(C6H5O7)2, M = 451.113 g/mol. Trimagnesium dicitrate — three magnesium atoms per formula unit. |
| Magnesium malate | 15.5% | 77.7 mg | MgC4H4O5, M = 156.376 g/mol |
| Magnesium bisglycinate | 14.1% | 70.5 mg | Mg(C2H4NO2)2, M = 172.423 g/mol |
| Magnesium glycerophosphate | 12.5% | 62.5 mg | MgC3H7O6P, M = 194.362 g/mol |
| Magnesium lactate | 12% | 60 mg | Mg(C3H5O3)2, M = 202.445 g/mol |
| Magnesium taurate | 8.9% | 44.6 mg | Mg(C2H6NO3S)2, M = 272.573 g/mol |
| Magnesium aspartate | 8.4% | 42.1 mg | Mg(C4H6NO4)2, M = 288.495 g/mol |
| Magnesium L-threonate | 8.3% | 41.3 mg | Mg(C4H7O5)2, M = 294.495 g/mol |
| Magnesium orotate | 7.3% | 36.3 mg | Mg(C5H3N2O4)2, M = 334.483 g/mol |
Zinc
| Compound | Share of pure active | 500 mg → | Source |
|---|---|---|---|
| Zinc oxide | 80.3% | 402 mg | ZnO, M = 81.379 g/mol |
| Zinc sulfate | 40.5% | 202 mg | ZnSO4, M = 161.436 g/mol |
| Zinc acetate | 35.6% | 178 mg | Zn(C2H3O2)2, M = 183.468 g/mol |
| Zinc citrate | 34.2% | 171 mg | Zn3(C6H5O7)2, M = 574.338 g/mol. Trizinc dicitrate — three zinc atoms per formula unit. |
| Zinc bisglycinate | 30.6% | 153 mg | Zn(C2H4NO2)2, M = 213.498 g/mol |
| Zinc lactate | 26.8% | 134 mg | Zn(C3H5O3)2, M = 243.520 g/mol |
| Zinc picolinate | 21.1% | 106 mg | Zn(C6H4NO2)2, M = 309.586 g/mol |
| Zinc aspartate | 19.8% | 99.2 mg | Zn(C4H6NO4)2, M = 329.570 g/mol |
| Zinc orotate | 17.4% | 87 mg | Zn(C5H3N2O4)2, M = 375.558 g/mol |
| Zinc gluconate | 14.3% | 71.7 mg | Zn(C6H11O7)2, M = 455.674 g/mol |
Vitamin D3
These forms are declared directly as active amount on the label — converting via molar mass would be wrong. On file: Cholecalciferol.
Vitamin K2
These forms are declared directly as active amount on the label — converting via molar mass would be wrong. On file: Menaquinone-7 (MK-7), Menaquinone-4 (MK-4).
Different forms are not comparable mass for mass, so they are kept separate.
EPA
| Compound | Share of pure active | 500 mg → | Source |
|---|---|---|---|
| EPA (declared directly) | 100% | 500 mg | C20H30O2, M = 302.458 g/mol. Labels state EPA in mg per serving — converting would be wrong. |
| EPA triglyceride | 96% | 480 mg | C63H92O6, M = 945.423 g/mol. Tri-EPA glycerol as the calculation model — three EPA residues on glycerol. |
| EPA ethyl ester | 91.5% | 458 mg | C22H34O2, M = 330.512 g/mol. Reference is the free acid EPA. |
DHA
| Compound | Share of pure active | 500 mg → | Source |
|---|---|---|---|
| DHA (declared directly) | 100% | 500 mg | C22H32O2, M = 328.496 g/mol. Labels state DHA in mg per serving — converting would be wrong. |
| DHA triglyceride | 96.3% | 481 mg | C69H98O6, M = 1023.537 g/mol. Tri-DHA glycerol as the calculation model — three DHA residues on glycerol. |
| DHA ethyl ester | 92.1% | 461 mg | C24H36O2, M = 356.550 g/mol. Reference is the free acid DHA. |
Creatine
| Compound | Share of pure active | 500 mg → | Source |
|---|---|---|---|
| Creatine anhydrous | 100% | 500 mg | C4H9N3O2, M = 131.135 g/mol. Anhydrous form — the substance is the active ingredient. |
| Creatine monohydrate | 87.9% | 440 mg | C4H9N3O2 · H2O, M = 149.150 g/mol |
| Creatine HCl | 78.2% | 391 mg | C4H9N3O2 · HCl, M = 167.593 g/mol |
| Creatine malate | 74.6% | 373 mg | 3 C4H9N3O2 · C4H6O5, M = 527.492 g/mol. Tri-creatine malate — three creatine molecules per malic acid. |
| Creatine citrate | 67.2% | 336 mg | 3 C4H9N3O2 · C6H8O7, M = 585.528 g/mol. Tri-creatine citrate — three creatine molecules per citric acid. |
| Creatine ethyl ester HCl | 67% | 335 mg | C6H13N3O2 · HCl, M = 195.647 g/mol. Reference is the creatine equivalent after the ethyl group is cleaved off. |
Data sources and limits
Prices and availability come from partner shops' product feeds and are refreshed daily. Nutrient values come from the manufacturer's label and are not lab-verified. Elemental shares are calculated from molar masses; every compound carries its source. Where a value is missing we show the gap instead of an estimate.
10. Price date and offers
Every offer carries the date it was recorded. The price may have changed between that recording and your visit; the price in the shop at the time of purchase is always the one that counts. Links to shops are ordinary links without tracking. The order in lists and comparisons follows the metrics. A code that applies to everyone without conditions is included in the price metrics — base price, discount and final price are always shown side by side. A code with a condition, such as a minimum order value or a restriction to first-time customers, is shown but explicitly not included: its value depends on your basket, not on the product. Expired codes are removed and no longer shown.