All cosmetics – lipsticks, make up, skin lotions, shampoos, etc. – may contain gluten, gluten derived ingredients or gluten cross contamination. Unfortunately cosmetics aren’t regulated like food is (at least where I’m from) and manufacturers don’t need to disclose this in their ingredients.
Of course gluten is only harmful to coeliacs if you ingest it so lipsticks/glosses are a priority. But if you’re like me and you bite your nails/have hand impairments and can’t always wash as thoroughly as you’d like, you might want gluten free everything to be safe.