Lipstick DOES contain fish scales.
Fish scales are sometimes added to cosmetics such as lipstick and nail polish to give it the same shimmering effect that they give the fish. Of course, you won't find the ingredient ‘fish scales' on your cosmetic labels. Not unlike the fancy term ‘caviar' that has been given to fish eggs, fish scales that are ground into a shimmery additive for cosmetics are called ‘pearl essence' or ‘pearlesence'.
What Is Pearl Essence?
Pearl essence, also called pearlesence, is the silvery substance found in the scales of shimmering fish such as the herring. The collection of pearl essence is a lucrative byproduct of the herring fisheries industry as it is sought after for use in cosmetics, paint, ceramics, nail polish, and jewelry.