Our Methodology

1. Data sources

We use a three-tier source hierarchy. Higher tiers are always preferred and override lower-tier data when conflicts arise.

Tier	Source	Grade
1	Official brand website ingredient listing	A
2	Amazon product detail page (brand-managed)	B
3	User submission (community-sourced, pending review)	C / D

2. Data confidence grades

Every product in our database is assigned one of four data confidence grades. This grade appears on product pages to help you understand how reliable the ingredient data is.

High confidence

Ingredient list sourced directly from the brand's official website or safety data sheet. Cross-referenced with physical product label where possible.

Good confidence

Sourced from Amazon brand-registered listing or equivalent third-party retailer with brand authorization. Not independently verified with physical label.

Moderate confidence

Community-submitted or scraped from non-authoritative source. Has been reviewed by our team but awaiting brand-level confirmation.

Low confidence

Unverified community submission or data older than 24 months without re-verification. Treat as indicative only — verify with physical label.

3. HEMA-free determination

A product is labeled HEMA-free on BuilderGel.app only if the following conditions are all met:

The ingredient list contains no HEMA (2-Hydroxyethyl Methacrylate) or any of its INCI synonyms
The ingredient list contains no Di-HEMA TMHDC (Di-HEMA Trimethylhexyl Dicarbamate) — a cross-reactive replacement that triggers HEMA allergy
The ingredient list contains no MMA (Methyl Methacrylate)
The ingredient list contains no HPMA (Hydroxypropyl Methacrylate)
The data confidence grade is C or higher

Note on "HEMA-free" labeling by brands: Some brands market products as "HEMA-free" while containing Di-HEMA TMHDC. This is technically accurate but misleading — Di-HEMA TMHDC is cross-reactive with HEMA and will trigger reactions in sensitized individuals. We flag these products accordingly.

4. Ingredient status labels

Each product receives a descriptive ingredient status based on the disclosed ingredient list we reviewed. These labels are not medical advice and do not mean a product is allergy-safe for every user.

Label	Meaning
No flagged ingredients disclosed	Reviewed disclosure does not list HEMA, HPMA, Di-HEMA TMHDC, MMA, TPO, or other ingredients BuilderGel.app flags.
Low-concern ingredient disclosed	HEMA-free in reviewed data, but one low-concern ingredient is disclosed.
Medium-concern ingredient disclosed	One or more medium-concern flagged ingredients are disclosed; no high-concern ingredient is disclosed.
High-concern ingredient disclosed	One high-concern ingredient is disclosed, such as HEMA.
Multiple high-concern ingredients disclosed	Two or more high-concern ingredients are disclosed, such as HEMA plus Di-HEMA TMHDC.

5. Update frequency

Grade A (brand website) data is re-verified quarterly. Grade B data is re-verified every 6 months. Products with a data confidence grade of D are flagged for re-verification on the next update cycle. Formulation changes reported by users are prioritized for immediate review.

6. Non-medical-advice statement

BuilderGel.app is an educational resource. Nothing on this site constitutes medical or dermatological advice. If you have experienced an adverse reaction to nail products, consult a dermatologist or allergist for proper diagnosis and treatment. See our full disclaimer.

7. Reporting errors

If you notice incorrect ingredient data, a missing product, or a formula change that hasn't been reflected in our database, please submit a correction.

Submit a correction or new product