How We Score Supplements

Why two scores instead of one

Most supplement scanners collapse everything into a single number. We deliberately don't. Every supplement on GoodSupp gets two independent scores: a Product Score for the formulation in the bottle, and a Brand Score for the company behind it.

They measure different things, and they disagree all the time. A well-certified brand can still ship a product with underdosed ingredients in poorly absorbed forms. A small brand with no certifications on file can still formulate an excellent product. Blend those into one number and both facts disappear — the average tells you neither what's in the bottle nor who made it.

Keeping them separate also keeps them honest: the Product Score can only be moved by changing the label, and the Brand Score only by earning verifiable certifications. Neither can subsidize the other.

The Product Score (0–100)

A product's score is the plain average of up to four independent sub-scores, each on a 0–100 scale. A product must have at least three computable sub-scores to receive a score at all — if we don't know enough, we show nothing rather than guess.

1. Label transparency

The share of active ingredients that disclose an actual amount on the label. A label that hides doses inside a proprietary blend scores 0 on this sub-score — you cannot evaluate what you cannot see.

2. Ingredient forms (bioavailability)

Each recognized active ingredient's chemical form is rated good, fair, or poor against our ingredient reference database (for example, magnesium glycinate versus magnesium oxide). The sub-score is the weighted share of well-absorbed forms: good forms count fully, fair forms count half, poor forms count zero.

3. Dosing vs. reference ranges

Each disclosed dose is compared against the effective range in our reference database. Doses within the range score 100, doses above it score 75, and doses below it — too little to matter — score 0. Nutrition facts like calories and sugars are excluded; only active ingredients count.

4. Other ingredients (additives)

The inactive ingredients — fillers, colorings, sweeteners, coatings — are checked against our knowledge base of 1752 ingredients, 121 of which are flagged as concerning with a severity level. Starting from 100, a product loses 35 points for each high-severity additive, 15 for medium, and 5 for low. Details for every flagged ingredient, with sources, are on our ingredient pages.

A worked example

Take a hypothetical magnesium supplement. The label lists 200 mg of magnesium as magnesium glycinate, plus rice flour and a vegetable-cellulose capsule:

• Transparency: 100. Every active ingredient discloses an exact amount — no proprietary blend.
• Ingredient forms: 100. Glycinate is a well-absorbed chelated form, rated good in our reference database.
• Dosing: 100. 200 mg falls within the effective range for supplemental magnesium.
• Other ingredients: 100. Rice flour and cellulose are unflagged, common excipients — no deductions.

Average of the four sub-scores: 100. Now swap the glycinate for magnesium oxide (a poorly absorbed form, rated poor) and hide the dose in a "relaxation blend": transparency drops to 0, forms to 0, dosing becomes uncomputable — and the same-looking bottle averages 33.

That gap — identical shelf appearance, wildly different formulation quality — is the whole reason the score exists.

The Brand Score (0–100)

The brand score is the average of up to three certification-based sub-scores: manufacturing standards (e.g. cGMP registration), independent testing (e.g. third-party purity programs), and quality certifications (e.g. NSF, USP, Informed Sport). A brand with no certification data gets no score — we do not penalize brands for gaps in our own records, and we do not invent numbers to fill them.

We separately track whether each certification claim is independently verified or merely claimed by the brand. Of the 3,905 certification claims in our database, only 1,240 (32%) are independently verified — the rest are the brand's own word.

We also maintain 3,805 public records across 1,556 brands — 1,362 lawsuits, 1,132 California Prop 65 notices, 725 recalls, and 586 FDA warnings — each stored with a link to the original public document and shown on the relevant brand page.

Where the data comes from

• Product labels — ingredient lists, amounts, and forms as printed by the manufacturer, sourced from product packaging and public label databases.
• Ingredient reference database — effective dose ranges and form quality ratings compiled from published nutrition research.
• Ingredient knowledge base — 1752 active and inactive ingredients with safety ratings and concern severity.
• Public brand records — FDA warning letters, recall notices, court filings, and Prop 65 listings, each stored with a link to the original document.

What we do NOT claim

• We do not lab-test products. Scores are computed from labels and public records, not chemical analysis. A great label can still hide a poorly made product.
• Scores are not medical advice. They say nothing about whether a supplement is right for you, your medications, or your health conditions.
• Scores are not user ratings. No score on this site represents human reviews, and we never mark scores up as star ratings.
• A missing score is deliberate. Where we lack data, we show N/A instead of a guess.
• Brands cannot pay for placement or scores. GoodSupp has no commercial relationship with any supplement brand.

Known limitations

• Labels can be wrong. We score what the manufacturer prints. If a label overstates its contents, only lab testing would catch it — and we don't lab-test.
• Reference ranges are population-level. An effective dose for most adults may be wrong for you specifically.
• Coverage is uneven. Well-studied ingredients have solid reference data; novel or niche ingredients may not be in our database yet, which lowers how much of a product we can evaluate.
• Data lags reality. Reformulations, new certifications, and new enforcement actions take time to reach our database.

Corrections

Label data changes, and parsers make mistakes. If a page shows incorrect information about a product or brand, tell us via the contact form — corrections ship with the next site build, typically within days. Read more about who runs GoodSupp on our about page.