Base head is street slang for a person who smokes freebase crack cocaine.
“Freebase” refers to the smokable form of cocaine, which comes in the form of crack cocaine, a hard, rock-like substance. Powder cocaine is actually cocaine hydrochloride, which is a water-soluble salt form of the drug.
Because it’s a salt, powder cocaine can be absorbed into the body, therefore it can be snorted or injected. Powder cocaine can be smoked but is not an effective method of using the drug.
Due to the fear of using infected needles, cocaine users began treating powder cocaine with chemicals to free the cocaine base from the hydrochloride. The result was a hard rock or lump of crack cocaine that was more easily smoked.
Smoking crack cocaine produces an almost immediate feeling of getting high. An initial “rush” of very pleasurable feeling lasts about two minutes followed by an intense high that lasts for about 30 minutes.
the pleasurable effects of crack cocaine wear off quickly, more quickly than when powder cocaine is snorted or injected. As it high wears off, the user begins to experience some very unpleasant after effects, including feeling:
Tired, depressed or anxious
Head and body aches
Sensitivity to light and sound