Preparation H is an over-the-counter hemorrhoid ointment also known for its off-label use as a treatment for dark circles. The idea is that because Preparation H works to temporarily shrink swollen tissue, topical applications to the under-eye area could temporarily de-puff bags. There is no solid evidence to support this theory, although Dr. G. Todorov of SmartSkinCare.com says that Preparation H might be good for an "emergency fix."
Regardless of whether or not the product works on dark circles, it is important to note that Preparation H is not intended for use on or near the eyes.
Gently wash your face with a mild cleanser. Follow with one or two splashes of cold water to help reduce swelling.
Lightly blot your face dry. Refrain from overzealous rubbing as this can further irritate the skin around the eyes.
Apply a thin layer of ointment to the affected area, avoiding getting the ointment into the eyes themselves. Wait until it is fully absorbed before applying makeup.