This is a randomized, cross-over, single-blind, placebo-controlled, single-center, multiple-panel evaluation of the potential for oral lorcaserin to modify cocaine self-administration in a laboratory setting. To prevent unauthorized drug use, study medications will be administered as participants are confined during overnight stays at the Medical Center. Non-treatment-seeking, regular cocaine users will receive oral treatment with single doses of placebo, lorcaserin 10 mg (Panel 1), or lorcaserin 20 mg (Panel 2). Afterwards, the subjective and reinforcing effects of intravenous cocaine will be measured in a laboratory setting.