The front of a bottle is a design decision. The Supplement Facts panel on the back has a required format, a required order, and required contents.
Read the second one. Here is what is on it, what each part is actually telling you, and the six checks that settle almost every question in under a minute — run on our own labels at the end, in the same order.
What is on a Supplement Facts panel?
A serving size, servings per container, the name and quantity of every dietary ingredient, and a percent Daily Value wherever one has been established. Ingredients without a Daily Value carry a dagger instead of a number. Anything that is not a dietary ingredient — binders, flow agents, flavours — sits below the panel under "Other ingredients."
Two of those are doing more work than they appear to be, and they are the first two.
Why is serving size the first thing to check?
Because every other figure on the panel is expressed per serving, and the serving is whatever the manufacturer decided it was. A bottle advertising 1,000 mg of something may deliver it across three capsules. Take one and you have taken a third. The headline on the front is frequently the per-serving number with the serving size left off.
The corollary is a pricing one. Divide the container price by actual daily servings, never by capsule count. A ninety-capsule bottle at three capsules a serving is a thirty-day bottle, and it should be compared against other thirty-day bottles rather than against other ninety-counts.
What does % Daily Value mean, and what does it not?
It is the amount per serving expressed against a published reference intake for an average adult. It is a comparison scale, not a personal target and not a recommendation. Many ingredients — botanicals, amino acids, most extracts — have no established Daily Value at all, which is what the dagger on the panel signifies.
Where it is genuinely useful is in catching quantities that are much larger than they look. Sodium is the standard example: a figure that reads as unremarkable in milligrams reads very differently as a share of a daily reference.
What is a proprietary blend, and why does it matter?
It is a group of ingredients disclosed as one combined weight, with the individual amounts withheld. Ingredients inside it must be listed in descending order by weight, which is the only information available. A blend is legal, common, and makes the panel uncomputable: nothing in this article can be run on one.
The practical rule is short. If the ingredient being bought sits inside a blend, the amount of it is unknown, and the descending order means it could be anywhere from most of the blend to a dusting at the bottom. Brands that can print their figures generally do, because a good number is the most flattering thing on a label.
Compound weight against active weight — the division that catches most people
Minerals arrive attached to something. A capsule of magnesium glycinate is mostly glycine by weight; the magnesium is a fraction of it. So a panel can print a large compound figure and a much smaller elemental one, both truthfully, and the elemental figure is the one that counts.
Read the "as" language carefully, because it is where the two numbers separate. Magnesium (as magnesium glycinate) 275 mg is an elemental claim. Magnesium glycinate 2,500 mg is a compound claim. Same capsule, different statements, roughly a nine-fold difference between the numbers.
The same structure appears across the shelf: mineral salts, chelates, and any ingredient described by a ratio. When a panel gives only the compound weight and no elemental figure, that is the answer to the question, and it is not a good one. The magnesium version of this arithmetic is here.
What does a certificate of analysis add, and what does it not?
A certificate reports what a laboratory found in a defined quantity of material. That is more than a label can offer. What it does not do is connect itself to the jar in a buyer's hands, and it does not necessarily assay the ingredient the jar is being bought for. Both limits are usually left unmentioned.
Two questions turn a certificate into information.
First: does it report measured results, or only specification limits? A specification is what a formula is supposed to contain. A result is what a test found in a run. Both are worth having, they are not the same thing, and a document that publishes one while implying the other is counting on nobody looking. Ours are split: two of four report results, two report limits only, and we say which at the top of every panel.
Second: does it assay the ingredient being paid for? A certificate can confirm identity and screen contaminants and stop there. That is a real document doing a real job, and it is not a potency document. Ask which one is on the table.
The longer version, with all four of our certificates transcribed row by row, is on Testing & Certification.
The sixty-second procedure
Six steps, in order, on any bottle in any cabinet.
- Check the serving size first. Every other number depends on it. Then divide the price by daily servings rather than by capsule count.
- Find the elemental or active figure. If the panel gives only a compound weight, or only an extract ratio, that is the finding.
- Divide. Active ÷ compound. The result is fixed by chemistry and it does not care what the front of the bottle says.
- Look for a proprietary blend. If the ingredient in question is inside one, stop. Nothing above can be calculated and the label has answered by declining to.
- Read "Other ingredients." Not to be scandalised by flow agents, which are ordinary, but to see whether the list is longer than the panel above it.
- Ask for the document, then ask what kind it is. Measured results or specification limits. Potency assay or identity and contaminants. A brand that cannot answer either question quickly has answered both.
Now run it on ours
Same six steps, same order, and this is where a label-literacy article usually goes quiet.
Night Work. Serving size three capsules, thirty servings, ninety capsules. Elemental figure printed on the front: 275 mg of magnesium from 2,500 mg of magnesium glycinate. Divide and it is 11%, which is what a glycinate looks like. One form, no blend. The certificate reports measured results — magnesium at 96.91 mg per capsule against a specification of greater than 91.6, which makes the measured serving 290.7 mg against a label claiming 275. We claim less than the document found and we publish both numbers.
First Food. One scoop, thirty servings, 2,300 mg of colostrum. Contains milk. Its certificate reports measured results — identity by FT-IR at 98.5% against a greater-than-95% specification, lead at 0.005 ppm against a limit of 3 — and runs no potency assay of any kind. Step six catches that, which is why the potency figure came off the front panel on 31 July 2026 rather than staying on it unsupported. The full account is here.
Training Water. One 10 g scoop, thirty servings. Creatine monohydrate 5,000 mg, sodium as sea salt 1,000 mg — about 43% of the daily value, which is exactly the sort of figure step three exists to surface. Its certificate reports specification limits and no measured results. There is also an open discrepancy we publish rather than resolve in our own favour: the label says a 10 g scoop and the certificate header says approximately 10.8 g. The four actives sum to the same 6,260 mg either way, so no dose changes, but a reader holding both will see two numbers.
Mineral Base. One capsule, thirty servings. Shilajit extract 30:1 at 400 mg, ashwagandha 100 mg, sea moss 100 mg, tongkat ali 100 mg — four figures, four lines, nothing in a blend. Its certificate also reports specification limits only, and for a mineral pitch that is the weakest place for a document to stop.
What a label can never tell you
Three things, and no amount of reading fixes them.
A panel is a claim, not a measurement. It states what the manufacturer says is in a serving. The document behind it is the only thing that turns a printed figure into a found one, which is why the last step of the procedure is about a document rather than a label.
A certificate names the lot it was run on, and that lot is not the buyer's. Naming a lot is exactly what separates a real certificate from a brochure — and a brand that never takes possession of inventory cannot connect the document to the jar that shipped. We would rather state the limit of our own paperwork than let anyone assume something larger.
No dietary supplement carries FDA approval, ours included, and registration would not be approval in any case. Structure/function claims carry an asterisk and a disclaimer; that is the system, and a label that implies more than that is telling you something about the brand.
Run the six steps on whatever is in the cabinet tonight. Then ask the last jar bought for a document with a number and a specification on it, and see what comes back. That is the whole exercise, and it costs a minute.
More in this cluster: 275 mg from 2,500 mg, the two numbers on a colostrum label, and every row of all four certificates.