What is the best part of the body to apply a Fentanyl patch?

It depends on the patient - by instruction, the patch must be applied on the upper torso or upper extremities (arms). Most people tend to put them on their back or chest, but I learned early on that for the back you need someone to change them, and the chest/stomach area has both too much hair and the skin flexes too much with activity.

As a result, for many years I've worn them on my biceps - they're flat, the patches easy to put on them with one hand, and the skin doesn't flex very much there. When using 1 100mcg patch, I just switch arms when it's time to put a new one on. When I have to increase to 2 100mcg patches, I use both arms, but take one off a few hours before the other to clean it and let the skin breathe before putting on a new one and taking the other one off. That way your dosage doesn't drop much during the process, and if you feel breakthrough you can take a Percocet or whatever your breakthrough med is to cover it.

The key to keeping a patch on (see the link to my answer on that below) is to make sure the skin is clean and there's no hair present. The literature says not to use any Isopropyl alcohol - that's because it leaves a residue. Problem is, it's difficult to remove skin oil and dirt without it. To get around the problem, clean it with Iso, then rinse the area well to make sure any residue is washed off. Dry the skin well, then apply the patch. If there's a lot of hair or micro-hairs, you might need to shave it off as well. Before you put the patch on, hold it between your hands (still attached to the backing) for about a minute to soften the adhesive. Apply it, then put your hand over it for another minute to ensure the adhesive gets a good bond to the skin. You'll find it sticks pretty well after that.