How the CuCu score works
One product, one honest number. Here’s how CuCu turns an ingredient list into a clear 0–100 score and where every flag comes from.
What the 0–100 score means
The score looks at every ingredient in the product. A high score means few or no documented concerns were found. A lower score means more ingredients were flagged by public scientific sources.
It’s based on the ingredients only, not the brand, the price, or the marketing. Two products with the same ingredient list always get the same score.
The five score bands
Lower score ≠ dangerous. A lower score means more flagged ingredients were found. It’s a conservative, informational signal, not a medical judgment about you or the product.
Why doesn’t CuCu check concentrations?
Most manufacturers don’t disclose exact ingredient percentages. A product with 0.001% fragrance gets the same flag as one with 5%. Because we can’t see the amounts, we flag the ingredient itself and stay on the cautious side.
How ingredient concerns affect the score
Every product starts at 100. Each flagged ingredient reduces the score based on how strong the documented concern is.
Stronger concerns weigh more
Ingredients with strong documented concerns reduce the score the most. Moderate and limited-evidence concerns have a smaller impact. If a regulator has prohibited an ingredient, the score can drop to zero.
Repeats count less
When several ingredients share the same type of concern, each extra one counts a little less. This keeps the score balanced and focused on the overall picture.
Conservative by design
When evidence is uncertain, CuCu leans toward caution. A data-quality indicator lets you see how complete the evidence behind each score is.
Types of ingredient flags
CuCu looks for ingredients that public sources have linked to these categories of concern:
Allergens
Ingredients that commonly trigger allergic reactions, including declared fragrance allergens.
Irritants
Ingredients documented to irritate skin or eyes, especially relevant for sensitive skin types.
Endocrine-disruption concerns
Ingredients under scientific or regulatory review for possible hormone-related effects.
Carcinogenicity concerns
Ingredients classified by bodies such as IARC in carcinogenicity categories based on published evidence.
Regulatory restrictions
Ingredients restricted, limited in concentration, or banned in major markets like the EU, US, or Canada.
Profile-specific cautions
Personalized flags based on your profile, like pore-clogging ingredients or ones that may need extra care during pregnancy.
Sources and references
Every flag in CuCu comes from publicly available scientific and regulatory references, the same ones dermatologists and safety experts rely on.
FDA
U.S. Food & Drug Administration cosmetic guidance and warnings.
Health Canada
Cosmetic Ingredient Hotlist of prohibited and restricted ingredients.
EU / SCCS
EU Cosmetics Regulation and the Scientific Committee on Consumer Safety.
CIR
Cosmetic Ingredient Review expert panel safety assessments.
IARC
International Agency for Research on Cancer classifications.
ECHA
European Chemicals Agency, covering REACH and substances of very high concern.
IFRA
Fragrance ingredient standards, where relevant to a product.
Open data
Public product databases such as Open Beauty Facts for product identification.
Important disclaimer
CuCu scores are informational and conservative. They are not medical advice, a diagnosis, or a guarantee that a product is safe or unsafe for you. Ingredient science evolves, formulations change, and every skin type is different. Always read the product label and talk to a qualified professional about medical or skin-health concerns.