A supplement can look inexpensive because it has a low bottle price, yet contain fewer servings or less of the declared active ingredient. Cost becomes meaningful only after the denominator is named. LabelLens therefore keeps each cost metric tied to a specific label quantity and a dated market offer.

Start with the labeled serving

FDA guidance says the Supplement Facts panel provides a serving size and the amounts of dietary ingredients per serving. It also generally provides servings per container. LabelLens uses those declarations rather than inventing a personal dose.

Cost per label serving

The base formula is:

Offer price ÷ declared servings per container

If a bottle costs $24.00 and declares 60 servings, cost per labeled serving is $0.40. This describes the manufacturer’s serving unit at the checked price. It does not say how often an individual should take the product.

Cost per unit

When container count is reliable, we can also calculate price divided by capsules, tablets, softgels, or another count unit. This is useful for pill-burden comparisons, but it can mislead if two products require different units per serving. The serving-size field must remain visible.

Cost per standardized active amount

For magnesium, the active denominator is declared elemental magnesium. For omega-3 products, a useful active denominator is declared EPA plus DHA. A standardized formula can be expressed as:

Cost per serving ÷ active milligrams per serving × 1,000

If a $0.40 serving declares 200 mg of the relevant active amount, the calculated cost per 1,000 mg is $2.00. This is a mathematical normalization, not a recommended serving and not a statement that different forms or formulations are clinically equivalent.

When LabelLens withholds a cost metric

• The offer price or currency is missing.
• The price-check date is too old for public use.
• Servings per container are missing or internally inconsistent.
• The relevant active amount is not declared.
• Values refer to different variants, pack sizes, markets, or serving bases.

Market and offer rules

Prices are scoped to a market and currency. We select among currently active, eligible offers using documented catalog rules. An affiliate relationship does not change the formula or factual product order. Shipping, tax, membership pricing, coupons, subscriptions, and multi-buy discounts are excluded unless the interface explicitly identifies and models them.

Rounding and freshness

Calculations use stored numeric values before display rounding. The interface may show fewer decimal places for readability. Every offer carries a checked date because retailer prices and availability can change after publication.

How to read the result

Cost metrics answer narrow questions. Cost per serving compares the label’s serving economics. Cost per active amount compares a declared quantity. Neither captures individual suitability, evidence quality, ingredient form, testing, convenience, or professional advice. Those remain separate decision inputs.

Sources and further reading

• FDA: Dietary Supplement Labeling Guide, nutrition labeling
• Electronic Code of Federal Regulations: 21 CFR 101.36
• LabelLens: How it works
• LabelLens: Affiliate disclosure

Source links were checked on July 18, 2026.