Trust Preparation H Cooling Gel with vitamin E and aloe for rapid cooling relief. It offers temporary relief from painful burning, itching and discomfort of hemorrhoids. Preparation H works by the activity of its active ingredient, phenylephrine, which temporarily narrows blood vessels in the affected area to decrease swelling. Preparation H Cooling Gel helps shrink swollen hemorrhoidal tissue and is non-greasy, non-staining with no unpleasant scent.