- Albuterol acts directly at beta receptors, while ephedrine works mostly indirectly by stimulating norepinephrine release. This allows greater activity from albuterol.
- Albuterol acts selectively at beta-2 receptors which promote fat loss, with relatively little effect at beta-1 receptors of the heart. In contrast, ephedrine works about equally at both receptor types. This selectivity enables higher effective dosing of albuterol for same or lesser effect on the heart.
- Albuterol does not activate alpha receptors, which act to impede fat loss. Ephedrine indirectly activates alpha receptors as well as beta receptors, which reduces its potential efficacy particularly with “stubborn fat.