I found Zanfel on the web a few years ago when in the middle of a nasty reaction to PI. Product was overnighted to me as it wasn't available in pharmacies like now. It worked WONDERS! Itching stopped almost immediately and swelling went down within 20 or 30 min. I recommend it to everyone and keep a tube on hand since I always get into PI every summer. I think its $39 at the local CVS around here and worth every penny at least to me. Anything that stops the itch is worth it.