What this is
Real Dosing compares supplement prices by $ per unit of active ingredient — not per serving or per bottle. A serving of magnesium glycinate and a serving of magnesium oxide both say "magnesium" on the front label, but one can cost over 80× more per mg of actual elemental magnesium than the other. This site makes that gap visible.
Every comparison is built from two sources: real label data pulled from the FDA's Dietary Supplement Label Database (DSLD), and manually verified retail prices from live product listings. No scraped estimates, no imputed values — if a product isn't priced from a real listing, it shows up unpriced rather than guessed.
Why it exists
Supplement marketing copy almost never makes the cost-per-mg gap obvious. A buyer comparing a $15 bottle of plain magnesium oxide to a $40 bottle of magnesium L-threonate has no easy way to see that they're paying 80× more per mg of the same mineral — the label shows different doses, different serving sizes, different serving counts, and different compound forms, all at once.
For categories like omega-3, the problem is sharper: most fish oil labels report only the total oil weight ("Fish Oil concentrate: 2000mg"), not the EPA/DHA content inside it. $/serving comparisons across those products are effectively meaningless — you have no idea what you're comparing. This site flags that too, rather than pretending the comparison is clean when it isn't.
How the data works
Label data comes directly from the FDA DSLD API. For minerals and DV-established vitamins, DSLD's label amounts are already the elemental or activity-equivalent quantity — confirmed by back-calculating against %Daily Value figures across each category's entire pull. For categories without an established DV (creatine, CoQ10, omega-3), we check whether the label quantity is directly comparable or whether it's a bundled source-weight figure that hides the actual active-ingredient content.
Retail prices are researched manually from live product listings and spot-checked for accuracy. Products that are out of stock, discontinued, or unavailable at a verifiable price are held unpriced rather than shown with stale data.
Coverage
Eight categories are currently live — browse all categories. More are added as the data is pulled and verified. If you search for a product and it isn't priced yet, you can request it and we'll look into it.
Business model
Real Dosing uses affiliate links (Amazon Associates, iHerb, and similar programs). When you click through to a retailer and make a purchase, we may earn a small commission at no extra cost to you. Affiliate relationships have no influence on which products are shown or how they're ranked — every table is sorted by the price metric, not by commission rate.
Contact
Questions, corrections, or data issues — email alphatronex@gmail.com.