Drug Class: sympatholytic antagonist (blocker) of alpha-2 adrenergic receptors (inject)
Average Reported Dosage: Men and Women 5-20 mCg per day
High Blood Pressure: Some reported high blood pressure
Yohimbine HCL is a sympatholytic agent, which means that its main function is to oppose stimulation of the sympathetic nervous system. In this case, it is a specific antagonist (blocker) of alpha-2 adrenergic receptors246. Yohimbine HCL is a prescription drug in many countries, and is used, among other things, to increase low blood pressure, to dilate the pupil of the eye, treat male impotence and stimulate fat loss. Common brand names include Aphrodyne,Viritab, Yocon and Yohimex. Due to the fact that yohimbine occurs naturally, it is in somewhat of a gray area in the U.S., where it is being tolerated as on OTC supplement ingredient at this time. It is likewise readily available here, and is a very common ingredient in the enormously crowded market for fat loss products.
To understand how yohimbine works, you need to first understand that adrenergic lipolysis (fat loss stimulated by adrenergic or sympathomimetic hormones) in human adipose tissue is regulated in a dual nature by adrenoceptors (the receptors that respond to these hormones). Most notably, activation of the beta-1, beta-2 or beta-3 subtype increases the process of lipolysis; while activation of alpha-2 receptors diminishes it. Fat cells appear to be the only type of cells in the human body that exhibit such dual regulation by adrenoceptors247. By antagonizing alpha 2 receptors, yohimbine can shift the balance of sympathetic activity to a place that measurably stimulates lipolysis248. This is further enhanced by an intrinsic ability to increase synaptic norepinephrine release249, one of the body's own natural lipolytic hormones. In effect, it serves both beta stimulating and alpha blocking properties, an ideal combination if we want to stimulate fat loss.
The typical dose used for fat loss is around 15-20mg, which is taken the first thing in the morning on an empty stomach. Some may opt to take a second dose later in the day, but this is an individual decision based on desired effect and tolerance to the drug's effects. Levels do build in the body over time, so it often takes a few weeks before you really notice any effect. When used at the recommended doses yohimbine is usually well tolerated. This is supported by not only anecdotal data but medical studies, which have shown single doses as high as 21.6mg, or daily cumulative doses as high as 43.2 mg, to have no significant impact on blood pressure or heart rate.This is, of course, the exact opposite of what
would be expected of a beta-agonist like ephedrine, which is a potent stimulant. Side effects are still always possible with this drug however, and can include increased heart rate, sweating, nervousness, tremor, irritability, headache, dizziness and
flushing. But these effects do tend to be very dose-related, so it is important not to overuse this drug in an attempt to produce a more dramatic fat-loss effect. One of the great advantages to yohimbine is that it can be a relatively comfortable compound to use. If taken in too high a dosage, you will see that change very quickly.