Studies have concluded that the ideal dosing for Yohimbine is .2mg/kg (11) -- this would be 20mg for a 220lb person.
The dosage of .2 mg/kg (approximately 1 mg per 10 lbs.) per day is relatively free of side effects and effective for weight loss (2, 3), while .1 mg/kg is more commonly used for sexual stimulant effects. For fat loss, yohimbine is generally taken twice daily, in the morning and afternoon. It is best taken on an empty stomach, as taking it with a meal can reduce its lipolytic effects (3). The half-life of yohimbine is short (1-2 hours), but the half-life of a metabolite with similar activity, 11-hydroxy-yohimbine, is 6-8 hours (18), so it is not necessary to take it every 2 hours. It is best to start with half the dose or less to see how sensitive you are to yohimbine, as inter-individual bioavailability and tolerance can vary greatly.