In cosmetics, claims are not just marketing language — they are legally binding statements. Regulators require them to be accurate, substantiated, and free from misrepresentation. This column, a summarised excerpt from the book Cosmetic Claims & The Myth of the Cheap Study, examines why compliance is not optional and outlines the financial truths behind safe, credible cosmetics.
Misleading vs. Substantiated Cosmetic Claims
A compliant claim must accurately reflect the supporting evidence. Selective presentation of results, exaggerated claims, or disclaimers hidden in fine print can make a claim misleading. For instance, if 35% of participants in a study report smoother skin, marketing the product as “clinically proven to smooth skin” would be misleading. A compliant claim would state: “35% of users observed smoother skin in a four-week study.” Visual evidence is equally scrutinised — before-and-after photographs must be standardised in lighting, angles, and conditions, with no filters, retouching, or cosmetic enhancements permitted.
Testimonials Are Not Evidence
Customer reviews and founder stories can be powerful marketing tools, but they also pose regulatory risks. If a consumer testimonial claims a product “cured eczema,” regulators may hold the brand responsible once the statement is published or promoted. The same applies to influencer marketing — regulatory authorities increasingly hold brands accountable for claims made by influencers on their behalf. As explored in a previous column on the evolving standards of cosmetic formulation, the industry’s shift toward transparency extends far beyond ingredients to encompass how products are marketed.
What Regulators Mean by Substantiated
Regulatory bodies expect evidence that is objective, verifiable, and reproducible. In cosmetics, substantiation typically includes a combination of consumer perception studies, clinical testing (in vivo), instrumental testing, in vitro or ex vivo studies, and literature reviews. No single method is universally sufficient — robust substantiation strategies combine multiple evidence types to support the claim.
The Hierarchy of Cosmetic Evidence
In vivo clinical studies — testing on human volunteers — remain the gold standard for proving product efficacy. In vitro studies investigate ingredient activity under controlled laboratory conditions and help explain mechanisms but cannot show real-world performance. Ex vivo studies use isolated human or animal tissue for more biologically relevant data. Consumer perception studies reflect how users experience a product and support claims related to perceived improvements.
Why Statistical Significance Matters
Evidence must be analysed correctly, not just collected. Statistical significance shows that observed results are unlikely to happen by chance. A study involving ten participants where 70% report improvement may be intriguing but is unlikely to be statistically significant. Regulators expect larger study groups and validated statistical analysis — often with a p-value below 0.05.
Compliance as a Strategic Advantage
Compliance is often seen as a restriction on marketing creativity, but it provides a foundation for credibility. Well-supported claims build consumer trust, safeguard brand reputation, and reduce regulatory risks. For emerging brands, investing in proper testing is vital for sustainable growth. Testing strategies should match the claims a brand intends to make, and collaborating with reputable laboratories ensures evidence is thorough, reproducible, and ready for regulators.
Theresa M. Callaghan is a cosmetic scientist and claims specialist. This column is a summarised excerpt from Chapter 2 of her book: Cosmetic Claims & The Myth of the Cheap Study.
