The present invention provides therapeutic formulations for solutions of .DELTA..sup.9 -tetrahydrocannabinol (.DELTA..sup.9 THC) to be delivered by metered dose inhalers. The formulations, which utilize non-CFC propellants, provide a stable aerosol-deliverable source of .DELTA..sup.9 THC for the treatment of various medical conditions, such as: nausea and vomiting associated with chemotherapy; muscle spasticity; pain; anorexia associated with AIDS wasting syndrome; epilepsy; glaucoma; bronchial asthma; and mood disorders.