A synthetic "poor man's" opioid. Acting almost exclusively on the mu-type opioid receptors (1 of 4 types) it is considered milder and less addictive than most other natural and semi-synthetic opioids. Used to treat moderate pain, it is most commonly sold under the brand name Ultram.
Its recreational use is limited, due to its relatively low strength, and higher incidence of side-effects when compared to other opioids. Many opioid users refuse to buy it, and its street value usually won't break $1.
It is still an opioid nevertheless, and can produce a relaxing high at upwards of 50mg, but its lesser effect, nauseating side effects, and longer reaction time makes it undesirable for most users.
I popped two 50mg tramadol tabs a few hours ago and now I'm puking my guts out! What the fuck?!