A skill to take anywhere

How To Read A Ratio On A Supplement Facts Panel

A number on a panel is not always the amount of the thing you came for. Ratios, salts, standardisation percentages and Daily Value bases all change what a weight means, and knowing the four of them turns a wall of milligrams into something you can actually compare.

By ProstaFlow Team · Last updated October 29, 2026 · 8 min read · Label reading · Reviewed by Dr. Al Borhan, MD

Why a weight is not always an amount

Start with the problem this skill solves. Two packs sit on a shelf, both printing 200 mg of an ingredient, both priced the same. One delivers 200 mg of the substance and the other delivers 90. Nothing on the front tells you which is which and both labels are entirely honest.

The difference lives in a few words printed beside the ingredient name: a salt, an extract ratio, a standardisation percentage. Those words are the part of a panel most readers skip and they are the part that decides what the milligrams buy.

None of this is a trick. It is the convention every supplement panel is written under, and the makers who volunteer the extra number are doing a reader a favour that regulation does not oblige them to do.

Salts, and the passenger in every one

Amino acids and minerals are usually sold bound to something, because the bare molecule is often unstable, hygroscopic or unpleasant to handle. The thing it is bound to has weight, and the printed figure is normally the weight of the pair.

The passenger can be light or heavy. A hydrochloride adds a proton and a chloride ion, which is a small proportion of the total. Malic acid is a much larger molecule, and a malate salt can be anywhere from half to two thirds the substance you came for depending on the proportion used.

Minerals work slightly differently and more helpfully. A calcium row printed as 18 mg with calcium carbonate in brackets is stating the elemental calcium, which is the figure that matters, so the bracket is describing the source rather than adding weight to be subtracted.

Six rows from one panel. Four resolve completely, one resolves approximately and one does not resolve at all, which is the ordinary distribution on a well-filled label.

A 2:1 ratio, worked through

Here is the sum, done slowly, on a real row.

The panel prints L-Arginine AKG 2:1 Extract at 200 mg. The 2:1 means two parts arginine to one part alpha-ketoglutarate by weight. Three parts in total, so each part is about 67 mg, and two of them are the amino acid. That is roughly 133 mg of arginine inside 200 mg of extract.

Add the free base row, which is 200 mg of arginine with nothing attached, and the capsule carries about 333 mg of arginine in total rather than the 400 mg that the two rows appear to promise. Sixteen per cent of the visible weight is the passenger.

That calculation took twenty seconds and it changes the number you would carry to a comparison. It is only possible because the label printed the ratio.

What the same sum looks like at 1:1

If the ratio had been 1:1, the 200 mg would carry 100 mg of arginine, and the capsule's total would be 300 rather than 333. Same printed weight, same ingredient name, a different amount in the capsule. This is the entire reason the small number matters.

The row with no ratio at all

The same panel then prints L-Citrulline Malate at 100 mg and gives no ratio, which makes that row unresolvable from the packaging.

Citrulline malate is sold as 1:1 and as 2:1, and the two carry substantially different amounts of citrulline for the same weight. The literature reflects that: the meta-analysis of eight studies pooled single doses of six to eight grams taken before lifting, and a 2025 head-to-head compared plain citrulline against citrulline malate directly, which is a comparison nobody would bother to run if the malate were incidental.

The honest way to read a row like that is to treat the 100 mg as the weight of the salt and to leave the amino acid content unstated rather than guessing at it. Guessing generously is how a panel gets credited with something it never claimed.

Percentages on a botanical

The same logic runs through botanical extracts, where it is expressed as a percentage rather than a ratio, and where the consequences are larger.

A row reading Lycopene 5% at 10 mg means ten milligrams of a preparation that is five per cent lycopene, which is half a milligram of the carotenoid. A reader taking the 10 mg at face value is out by a factor of twenty. The same convention applies to a pygeum bark standardised to 3 per cent phytosterols, or a curcumin standardised to 95 per cent curcuminoids.

A botanical row carrying a weight, a plant part and no percentage at all is the least informative kind of entry on any panel. It is not against the rules and it leaves the extract strength entirely to the maker.

Daily Value percentages and their basis

The last of the four numbers behaves differently again, and it is the only one that can be checked against a published figure.

Checking a label's own arithmetic takes two minutes and tells you something about how carefully the rest of it was prepared. This one passes.

Both percentages on this panel are right for the reference figure they are calculated against, and neither has been rounded upward to flatter the row. The calcium line is worth a note: 1.5 per cent is correct on a 1,200 mg basis, while against the 1,000 mg recommended for men aged 51 to 70 it would read 1.8. That is a rounding basis rather than an error, and either way the row is under two per cent of a day's requirement.

Rows carrying no percentage at all are not hiding anything either. No Daily Value has ever been set for arginine, citrulline or beta alanine, because there is no established daily requirement for them. The ISSN position stand on beta-alanine gives a working range for a performance effect, which is a different kind of figure from a requirement and is never printed on a panel.

Five ratio questions for any panel

Take these to the next label you pick up. They work on any category, not just this one.

1. Is this a free base, a salt, or an extract? The words in brackets answer it, and the answer decides whether a sum is needed at all.
2. If it is a salt or an extract, is the ratio printed? With one, do the sum. Without one, treat the weight as the weight of the salt and leave the rest unstated.
3. If it is a botanical, is there a standardisation percentage? Five per cent of 10 mg is half a milligram, and the difference between those two figures is where most botanical marketing lives.
4. Does the Daily Value arithmetic check out? Two minutes with a search engine and a calculator tells you something about how carefully the rest of the label was prepared.
5. Once resolved, how does the amount compare with the dose its research used? This is the question all the others were clearing the way for.

Run those five and a panel stops being a wall of numbers. It becomes a short list of resolved amounts you can set against a short list of published ones, which is the only comparison that decides anything.

The panel page applies all five to this particular bottle, and the ingredients page prints the resolved amounts as a table.

References