I believe ctrl z has nailed how low dose Naltrexone works in treating IBD. Then again, I'm no doctor, or scientist, etc.. Just someone who has used LDN to treat my disease since late 2007. I've always/only used an oral dose compounded by one of several local pharmacies that have the proper equipment to make these little capsules for me. Thing of it is, despite they (pharmacies) and I being nearly 5 years into this experiment, there have been bumps along the road. Stale Vs fresh compound for example. My anecdotal info got the pharmacies to delve a little deeper into how long compound mixture retains its potency AND revise their practices. Now, what is involved in taking bulk Naltrexone and putting the proper dosage into a transdermal patch which then delivers that drug to the body in a method AND timeline consistent with treating Crohns (or any form of IBD) I don't know... and I wonder/worry whether anyone has the answer to that question. It may be that the process of putting 4.5mg of Naltrexone into a patch is quite easy, and it also may be that it doesn't affect how it delivers the drug... but has that been tested? My concern is that 4.5mg transdermal patches of Naltrexone may work for other issues like MS, whatever, etc., but have never been clinically trialed for treating IBD. And if some fundamental things like fresh Vs stale powder affect compounded capsules, what other potential unknowns might affect how well or whether if at all transdermal forms of the med will work. If I were starting from scratch today on LDN, I wouldn't take the chance of going a route that hasn't been trialed and proven successful. There is just too much to lose. No, I would go the tried N tested route first, and only deviate from it if there was some confirmed, overwhelming reason to experiment with transdermal. That is just my humble opinion, but I believe it makes good old fashioned horse sense.