Researchers analyzed claims made in cosmetic ads and found that the majority of those claims were vague and many were outright lies.

A new study published in the Journal of Global Fashion marketing assessed claims made in 289 cosmetic ads for products including make-up, skin care and fragrances. 

Advertising for these products often included claims like “clincially proven” but researchers say only 18 percent are generally trustworthy.

The authors conclude that even those that back claims with “consumer testing” or “scientific evidence” often use questionable methods.