Different people react differently to opiates but like negrogesic said, if they melt away all your pain, the temptation to keep using them will be irresistible.
If you decide you want to try it despite the risk, do not use heroin as your first opiate. Heroin will jack up your tolerance, the quality will be unpredictable, and the potential for OD is massive especially with all the fentanyl that is passed off as heroin nowadays.
Find legitimate pharmacy pills for your first time. There are a lot of fake pills too so watch out, the most commonly faked pills are any form of oxycodone and morphine, but other pills can be faked too.