I was quite curious about Capsa Lip Plumper from nomakenolife beauty box (February) as it contains pepper extract. The one in my box is a clear gloss and I apply it before lipstick. It gives a tingling sensation, perhaps that is what makes lips plumper. Not remarkably plumper but I do notice the difference especially when I have applied lipstick over it.
There are 2 other variations to this product which are red and moisturizing serum. I think clear is useful as it gives a slightly fuller lip effect and makes lips look glossy when you wear it under any lipstick.