Spotty, I have had seemingly intractable ED for over 20 yrs and have a little experience with several different injectables. The combination that works best for me is a Bi-Mix of PGE-1 20mcg/ml and Phentolamine 1mg/ml. I also tried a tri-mix with papaverine 30mg/ml, phentolamine 1mg/ml and PGE-1 10 mcg/ml but it was not nearly as effective. Caverject worked about
as well as the tri-mix. The two mixtures I mentioned above are the most popular combinations at the pharmacy that I use. For me it was just a little trial and error so to speak. Do take a good look at James instructions, as I found them very helpful.