What does heroin in smoke form smell like?

Heroin in its smoked form typically has a faint, vinegar-like smell due to the acetic anhydride used in its processing. Some users also describe it as having a slightly sweet or burnt odor, reminiscent of tobacco or burnt sugar. The specific scent can vary depending on the purity and any additives present in the substance. Overall, the smell is often subtle and may not be immediately recognizable to those unfamiliar with it.