Evidence & Sources

Sourcing policy (short)

We prioritise primary evidence and regulatory reviews. Our default evidence hierarchy is:

1. Regulatory assessments & systematic reviews (authoritative agency opinions, Cochrane-style reviews).
2. Peer-reviewed human clinical studies with relevant dermal exposure data.
3. Validated animal toxicology studies where dermal models are applicable.
4. High-quality in vitro mechanistic studies informing potential modes of action.
5. Case reports and surveillance data (used to flag allergens or rare events).

We treat industry-only reports and preprints as supplementary and label them clearly; they do not override higher-tier evidence unless later confirmed by peer review or regulatory updates.

Primary databases and resources we consult

Typical sources we search include (but are not limited to):

• Regulatory bodies: European SCCS opinions, FDA consumer and safety summaries, Health Canada assessments where relevant.
• Scientific literature: PubMed / MEDLINE, Scopus, Web of Science for peer-reviewed articles.
• Toxicology databases: ECHA dossiers, ToxNet archives, OECD reports.
• Dermatology guidance: Consensus statements, clinical practice guidelines, and position papers from dermatology societies.
• Adverse event reporting: National surveillance and voluntary reporting systems (used to detect signals, not to prove causation).

When we cite a study, we include DOI, PMID, or direct agency URL whenever available to make retrieval straightforward.

Citation & transparency practice

Each ingredient or product page carries a short “Sources” list linking to the most relevant documents used in that evaluation, and where commonly cited research frameworks are referenced, we explain how those approaches are interpreted in practice in our ACE-based soap research overview. We use the following conventions:

• Primary citation: The key regulatory review or highest-tier study that most influenced the conclusion is placed first.
• Supporting citations: Additional human studies, mechanistic papers, and surveillance reports follow.
• DOI/PMID/URL: We include at least one persistent identifier when available (DOI or PMID). For agency documents we link directly to the published opinion or dossier.
• Changelog link: For substantive updates we include a changelog entry with date, reason, and the new evidence that prompted the change.

Example citation format we use on pages: Smith et al. 2019. Journal of Derm. DOI:10.1000/xyz.

Reproducibility & requests for primary data

We archive the exact search terms, databases, and selection dates used to build each ingredient summary. For qualified researchers or reviewers, we provide:

• Search strings and date ranges used to identify literature.
• Copies of public documents (or direct links) referenced in the entry.
• Anonymised aggregated notes from consumer reports when relevant and where privacy allows.

To request reproducibility materials, use the contact page and specify the ingredient or product and the materials you need. We evaluate requests for legitimacy and privacy impact before sharing.

Quality control & peer checks

Every substantive piece of content (new ingredient flags, product risk-context notes) goes through a two-person review process:

CleanFormulation research may involve multiple contributors including research writers, formulation researchers, and subject-matter reviewers. All contributors participating in the preparation of a page are listed on that page and on the Editorial Team & Contributors page.

1. Primary author / researcher: collects sources, drafts the summary and rationale.
2. Secondary reviewer: independent check of source selection, interpretation, and whether conclusions follow logically.

When disagreements arise, we escalate to an external consultant with relevant expertise for independent perspective.

Limitations you should know

Transparency does not eliminate limitations. Common issues we face:

• Paywalled literature: Some high-quality studies are behind paywalls. We summarise findings and provide DOIs so readers can retrieve originals through libraries or institutional access.
• Incomplete product data: Manufacturers rarely disclose exact ingredient concentrations; we use ranges or supplier information when available and state assumptions clearly.
• Emerging science: Preprints and early mechanistic studies can suggest risks that later evidence may refute, we flag early signals but base our summaries and interpretations on higher-tier evidence when possible.

How to cite CleanFormulation

If you refer to our summaries in academic or public writing, cite the specific ingredient/product page and include the "last reviewed" date. Example:

CleanFormulation. "Ingredient X, summary." Last reviewed Nov 7, 2025. https://cleanformulation.com/ingredient-x

If you use our archived reproducibility materials, please acknowledge CleanFormulation as the curator and link back to the relevant page.

Corrections & disputes

Found an error? We welcome corrections. Our corrections workflow:

1. Submit the correction via the contact form with supporting evidence.
2. We acknowledge receipt within 7 business days and provide an estimated review timeline.
3. After review, we publish a correction note on the page if the change is substantive, including the rationale and source that triggered the correction.

This public corrections approach is part of our transparency commitment.