In the UK, heroin, fentanyl & morphine are all Class A drugs with potential maximum penalties of life imprisonment for the upper end of importation.
In conclusion, if one does die taking these drugs, the death is likely to be very peaceful. Morphia is, after all, the goddess of dreams.
To recap, the problems that are common to all opioids include tolerance, sensitivity and the existence of an effective and fast- acting antidote. These issues make the use of the commonest opioids (eg. morphine, heroin and methadone) less desirable than they may first appear. In regard to heroin, because it can only be purchased illegally, its purity will remain an issue of concern. The same applies to the fentanyl analogues in terms of illegality, despite the potency and effectiveness of these new synthetic options.