Yohimbine is a naturally sourced pharmacological agent, which produces hyperadrenergic physiological effects. In excess doses, it may typically cause agitation, anxiety, hypertension, and tachycardia. There is no conclusive evidence for this drug to be of benefit in bodybuilding, exercise tolerance, physical performance, or desirable alterations of body mass. Although tolerated generally well in low doses, the potential for dose-dependent toxicity should be recognized.