How long are opiats detectable in the body?
How long a drug is detectable in your blood or urine depends on a number of factors. How often and how much you use and your personal metabolism (the speed at which the breakdown substances of a substance are broken down by your liver, in particular) influence how long it is detectable. Drugs are longer detectable in your urine than in your blood.
Heroin itself is usually detectable up to 8 hours after use. Tests usually look at the metabolite of heroin and these are detectable 3 to 5 days after use.