Which drug when injected can have addictive properties similar to heroin?

Methadone is a long-acting opioid that can create effects similar to heroin when injected, including euphoria and the potential for addiction. It acts on the same opioid receptors in the brain as heroin, which contributes to its addictive properties. Methadone is often used in controlled settings for the treatment of opioid dependence due to its ability to reduce cravings and withdrawal symptoms. However, when not used as prescribed, it can lead individuals to seek it out for its psychoactive effects, which parallels the addictive nature of heroin.

In contrast, buprenorphine, while also an opioid used in addiction treatment, has a ceiling effect that limits its euphoric properties compared to methadone and heroin. Cocaine, on the other hand, is a stimulant rather than an opioid, and its addictive properties arise primarily from its effects on dopamine rather than through opioid receptor activation. LSD, as a hallucinogen, does not produce the same type of physical dependence and addiction associated with opioids like heroin and methadone.