What 49 electrolyte labels say and what a gram of sodium costs

Each label’s figure is the one the electrolytes ranking prints: its lowest price per serving among the sizes in stock at the brand’s own store, up to 5 kg, divided by the grams of sodium a serving states. 47 of the 49 labels (96%) have one; the rest had no in-stock size up to 5 kg with a servings count on the day prices were read.

Across those 47, the median is $4.54 per gram of sodium. The middle half runs from $2.41 (lower quartile) to $8.33 (upper quartile): a quarter of the 47 cost less than $2.41 a gram and a quarter more than $8.33.

Flavours count separately. Each flavour with its own label is its own record here. Of the 11 brands with two or more priced labels, 2 price all of them at one price per serving, so a brand with many labels weighs more in these medians: the most labels from one brand is 9 of the 49. Counting each brand once instead (the median of each brand’s own median), the median across the 20 brands with a cost per gram is $3.72 per gram of sodium.

Why sodium. The ranking prices this shelf on sodium alone, not on the total of every mineral: sodium is the mineral these labels state most consistently (below), so the figure compares like with like. Pricing on sodium does not say the minerals substitute for one another. The electrolyte label guide walks through the arithmetic with a worked example.

The same product, in different sizes. A product’s sodium per serving is the same in every size, so a size is measured here in the servings it holds. 24 of the 49 products have a priced size whose servings the store’s option itself states, by weight or as a servings count, 38 sizes in all.

10 of those 24 products are priced in two or more sizes. In 10 of those 10 (100%) the largest size costs less per gram of sodium than the smallest; in 0 it costs the same, and in 0 more. The median difference is 31% less per gram at the largest size than at the smallest.

49 of the 49 labels state sodium as a number; across those 49, the median is 150 mg a serving, and the figures run from 55 mg to 1,200 mg. A serving is whatever the label calls one, a scoop, a stick or a number of tablets, so a price per serving compares unlike amounts of sodium; cost per gram of sodium divides that difference out. The site’s reference recognises sodium, potassium and magnesium and gives none of them a threshold (how we rate), so no label here is marked as meeting or missing a dose; the amounts are described as printed.

Which minerals a label states. A mineral counts as stated when the label gives it as a number: its nutrient line, or, for sodium, potassium and magnesium, a row the panel doses outside a blend, as the electrolyte label guide counts them. 42 of the 49 labels (86%) state all three of sodium, potassium and magnesium. A label can be in more than one row of this table:

Amounts. Potassium and magnesium amounts are taken from the panel’s potassium and magnesium lines only. A row named for a salt, such as potassium citrate, carries the weight of the whole compound, not of the mineral in it, so it is never used as a mineral amount.

A label’s sodium divided by its potassium, both in milligrams as the panel states them: how many milligrams of sodium come with each milligram of potassium. 47 of the 49 labels state both; across those 47, the median is 0.58, and the middle half runs from 0.40 to 1.67. 20 of the 47 (43%) state more sodium than potassium, 25 of the 47 (53%) more potassium than sodium, and 2 the same amount of each. The ratio describes the label’s arithmetic only; it is not a score and not a target.

28 of the 49 labels carry a sugar amount in the label data; across those 28, the median is 0 g. 16 of the 49 (33%) state 0 g, 12 of the 49 state more than 0 g, and 21 of the 49 (43%) have no sugar row in the label data. A label with no sugar row is counted as carrying no amount, never as 0 g.