Appetite stimulation by cannabinoids is highly variable. Four within-subject design studies explored the effects of age, gender, satiety status, route of drug administration, and dose on intake. One study involved a single oral administration of active drug (15 mg males, 10 mg females) or placebo to an age and gender stratified sample of 57 healthy, adult light marijuana users. Eleven subjects received single doses by oral, sublingual, and inhaled routes in a second study. In the third study, 10 subjects ingested a single oral dose in fasted and fed states. A 2.5 mg dose was administered b.i.d. for 3 days by oral and rectal suppository routes in the fourth study. Mean daily energy intake was significantly elevated following chronic dosing by rectal suppository, but not oral capsule, relative to all acute dosing regimens except inhalation. Total daily energy intake was comparable on fed and fasted days, suggesting satiety mechanisms were not impaired by the drug. Subject age, gender, reported "high," and plasma drug level were not significantly associated with drug effects on food intake.