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Label Accuracy

Labdoor's Label Accuracy score is based on a product’s measured levels of active ingredients vs. its label claims.

Products are penalized if their measured active ingredient levels don't match their claimed values. Penalties are twice as heavy if a product has less than what they claim (underage) compared to if they have more (overage). In 2017, we began applying FDA rounding rules to scoring. With this, if rounded test results don't match products' claims, a penalty is applied based on the deviation between unrounded measured values and claims. Older categories will be updated to follow suit. In multiple-ingredient products, scores for individual nutrients are combined for a final Label Accuracy score.

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Product Purity

Labdoor's Product Purity score is based on a product's contaminant levels.

In most of Labdoor's supplement categories, default purity assessments consist of heavy metal assays. Alternative or additional screenings are sometimes performed depending on the specific category. Whenever possible, laboratory results are compared to guidelines from state, federal, and international health organizations defining the lowest levels of these contaminants with potential effects on human health. These can include proposed and established Maximum Allowable Dose Levels (MADLs) and No Significant Risk Levels (NSRLs) from California's Prop 65, Reference Doses (RfDs) from the US Environmental Protection Agency (EPA), and Minimal Risk Levels (MRLs) from the US Agency for Toxic Substances and Disease Registry (ATSDR). This procedure was adopted for Labdoor's more recent categories. Older categories will be updated to follow suit.

California's Office of Environmental Health Hazard Assessment (OEHHA) states that "the purpose of Proposition 65 is to notify consumers that they are being exposed to chemicals that are known to cause cancer and/or reproductive toxicity. Consumers can decide on their own if they want to purchase or use the product. A Proposition 65 warning does not necessarily mean a product is in violation of any product-safety standards or requirements."

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Nutritional Value

Labdoor's Nutritional Value score is based on levels of a product's macronutrients and other supporting nutrients.

Products are rewarded and penalized for their macronutrients based how they meet or exceed Dietary Reference Intakes (DRIs), recommendations established by the Institute of Medicine of the National Academies for daily intake. Assessed macronutrients include, but are not limited to, calories, protein, fat, cholesterol, carbohydrates, sodium, and sugar. If a product contains other supporting nutrients like secondary vitamins and minerals, their levels are also compared to DRIs and factored into the product's final Nutritional Value score. If DRIs are not applicable, an evaluation of peer-reviewed research is performed to determine relevant thresholds.

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Ingredient Safety

Labdoor's Ingredient Safety score is based on whether a product has: 1) active ingredients at unsafe levels and/or 2) additives with potential health risk.

Products are penalized as their active ingredient levels approach or exceed established Tolerable Upper Intake Levels (ULs). The National Institutes of Health (NIH) defines ULs as "the highest level of nutrient intake that is likely to pose no risk of adverse health effects for almost all individuals in the general population. As intake increases above the UL, the risk of adverse effects increases." When ULs have not been established, other applied thresholds may include No-Observed-Adverse-Effect Levels (NOAELs), Minimal Risk Levels (MRLs), or values derived from an evaluation of peer-reviewed research.

Each product's additives, or excipients, are also evaluated for their potential effects on human health. These ingredients are assigned weights based on FDA "Generally Recognized As Safe" (GRAS) status, research surrounding their safety, and the severity of their potential risks. Related penalties are then applied to final Ingredient Safety scores.

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Projected Efficacy

Labdoor's Projected Efficacy score is based on a product's active ingredients, their levels, and their specific biochemical properties.

Each product is assessed based on the quantity of each of its active ingredients and how well the body can absorb and use them. The latter can be attributed to a variety of factors, including the bioavailability of each ingredient's form (e.g. zinc oxide vs. zinc citrate), their pharmacokinetic (PK) profiles, their concentration (e.g. EPA and DHA in fish oil), and their combination with other ingredients in the product. Bioavailability indicates the fraction of a nutrient's dose that reaches the bloodstream, and a PK profile represents how a substance is absorbed and distributed in the body. This information is curated from peer-reviewed research as well as expert consultations. Scores for individual active ingredients are combined to generate a final Projected Efficacy score.

*Because research evolves, we actively adopt new testing and scoring methods to ensure that our information is up-to-date. We also regularly re-test existing products and test new ones. As such, we retain the right to update our scoring algorithms, product data, and rankings at any time. Updates are published here.