How much more opiate is in a hit of street heroin than your usual medical injection of IV morphine for traumatic pain? I've had the latter and while it was fair

How much more opiate is in a hit of street heroin than your usual medical injection of IV morphine for traumatic pain? I've had the latter and while it was fairly awesome, it's not exactly world-changingly addictive either. I'd rate it about the equal of alcohol on your scale.