I use heroin, oxycodone, morphine, Rx benzos (xanax and klonopin) and I have used lots of fentanyl, normal NN-fentanyl, and also a few analogs. .. But yes if u can get even 10mg of pure fentanyl you can have a very pleasant and peaceful death, idk how much more would be needed. however most fentanyl you will encounter is cut very much. but enough + benzos and other cns depressants and it 'could' work.. orally you'd need a much larger amount, so if it not pure idk, but if it is, its peaceful based on my experiences. fentanyl transdermal patches are another option.