Potency Testing
Verifying that the amount of active ingredient matches the label claim - usually by HPLC.
Potency testing (also called assay) measures how much active ingredient is actually present and confirms it matches your label claim. USP monographs generally allow plus or minus 10% of label claim for most dietary ingredients.
The gold-standard method for most botanical actives, vitamins, and amino acids is HPLC; minerals use ICP-OES. This is the test customers and class-action lawyers care about most - under-delivering on a labeled amount is misbranding. Expect roughly $80-$300 per active.
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