Yohimbine
Also known as: Yohimbe, Corynanthe Yohimbe, Yohimbe Bark, Pausinystalia Yohimbe
Overview
Yohimbine is a naturally occurring alkaloid found in the Pausinystalia yohimbe tree and the Rauwolfia serpentina plant. Yohimbine is a stimulatory compound that primarily acts on the alpha-2-adrenergic receptors in the body. It’s best known for its ability to increase fat burning and aid in male sexual dysfunction. Yohimbine supplementation is also used for weight loss, body composition, treatment of phobias, and orthostatic hypotension, though there is a lack of evidence to support yohimbine’s benefits for many of these conditions.
Benefits
Yohimbine is a selective alpha-2-adrenergic antagonist. In other words, it targets and inactivates a class of receptors in the nervous system that is responsive to the neurotransmitter norepinephrine. Alpha-2 receptor antagonism enhances the sympathetic nervous system release of norepinephrine, causing the stimulatory and hyperadrenergic effects of yohimbine. Antagonism of alpha-2 receptors also inhibits penile smooth muscle contraction and may enhance nitric oxide-mediated smooth muscle relaxation — the combined effects of which promote erection and explain the improvement in ED symptoms after supplementing with yohimbine. Yohimbine also inhibits the activity of alpha-2 receptors on fat cells — where norepinephrine normally acts to suppress fat release. Inhibition of the antilipolytic effect of norepinephrine allows more lipolysis (fat burning) to occur.
How it works
Some evidence supports the use of yohimbine as a natural way to improve symptoms of erectile dysfunction (ED) in men. While studies have questioned this claim, two meta-analyses concluded that yohimbine taken alone or alongside other therapies, including arginine and PDE-5 inhibitors, improves ED when compared to a placebo, though studies using combined yohimbine and PDE-5 inhibitors have only been conducted in animals. Although it’s often marketed as a fat-loss and performance-enhancing supplement for athletes, there’s no evidence that yohimbine improves strength, increases muscle, or enhances physical performance. Yohimbine does seem to have a lipolytic effect (increases fat burning) and may improve body composition or cause regional fat loss when used as a topical ointment.
Side effects
Total daily dosages of 0.2mg/kg bodyweight have been successfully used to increase fat burning without significant implications on cardiovascular parameters like heart rate and blood pressure. This results in a total daily dosage of: 14 mg for a 150 lb (68 kg) person, 18 mg for a 200 lb (91 kg) person, 22 mg for a 250 lb (113 kg) person. These total daily doses are often divided and taken in two to four doses throughout the day. For example, a 150 lb (68 kg) person could take 7 mg twice daily to reach a total dose of 14 mg. Supplementation is most effective between meals or during short term fasting. Caution should be exercised at higher body weight, since the cardiovascular system may not be prepared to handle a stimulatory agent such as yohimbine. When supplementing yohimbine for the first time, always start with a half-dose and assess tolerance before proceeding. Caution should also be exercised since many supplements containing yohimbine either do not list how much yohimbine is included, or if they do, the actual dose ranges from 25-150% of the dose listed. Since the dosage may be higher than listed, this is extra reason to start with a lower dose. When pairing yohimbine with other stimulatory agents, half-dose both supplements and work up to the recommended dose cautiously, as two supplements can interact negatively.
Dosage
When taken at the recommended dose (≤0.2 mg per kg of body weight), yohimbine may cause nausea, abdominal pain, dizziness, nervousness, and anxiety. Higher doses of yohimbine may be dangerous; a report from 2005 found that yohimbine had the highest rate of toxic effects of any botanical product. Case reports of excess yohimbine ingestion have suggested that anxiety, hypertension (high blood pressure), tachycardia (high heart rate), arrhythmias, and agitation are among the more severe side effects of this compound. Furthermore, many yohimbine-containing supplements in the U.S. were found to be inaccurately labeled — they contained 23%–147% of the yohimbine reported on the label and failed to report the amount of yohimbine contained in the product or warn of the potential harms of excess consumption.
FAQs
What is yohimbine?
Yohimbine is a naturally occurring alkaloid found in the Pausinystalia yohimbe tree and the Rauwolfia serpentina plant. Yohimbine is a stimulatory compound that primarily acts on the alpha-2-adrenergic receptors in the body. It’s best known for its ability to increase fat burning (lipolysis) and aid in male sexual dysfunction. Yohimbine supplementation is also used for weight loss, body composition, treatment of phobias, and orthostatic hypotension, though there is a lack of evidence to support yohimbine’s benefits for many of these conditions.
What are yohimbine’s main benefits?
Some evidence supports the use of yohimbine as a natural way to improve symptoms of erectile dysfunction (ED) in men. While studies have questioned this claim, two meta-analyses concluded that yohimbine taken alone or alongside other therapies, including arginine and PDE-5 inhibitors, improves ED when compared to a placebo, though studies using combined yohimbine and PDE-5 inhibitors have only been conducted in animals. Although it’s often marketed as a fat-loss and performance-enhancing supplement for athletes, there’s no evidence that yohimbine improves strength, increases muscle, or enhances physical performance. Yohimbine does seem to have a lipolytic effect (increases fat burning) and may improve body composition or cause regional fat loss when used as a topical ointment.
What are yohimbine’s main drawbacks?
When taken at the recommended dose (≤0.2 mg per kg of body weight), yohimbine may cause nausea, abdominal pain, dizziness, nervousness, and anxiety. Higher doses of yohimbine may be dangerous; a report from 2005 found that yohimbine had the highest rate of toxic effects of any botanical product. Case reports of excess yohimbine ingestion have suggested that anxiety, hypertension (high blood pressure), tachycardia (high heart rate), arrhythmias, and agitation are among the more severe side effects of this compound. Furthermore, many yohimbine-containing supplements in the U.S. were found to be inaccurately labeled — they contained 23%–147% of the yohimbine reported on the label and failed to report the amount of yohimbine contained in the product or warn of the potential harms of excess consumption.
How does yohimbine work?
Yohimbine is a selective alpha-2-adrenergic antagonist. In other words, it targets and inactivates a class of receptors in the nervous system that is responsive to the neurotransmitter norepinephrine. Alpha-2 receptor antagonism enhances the sympathetic nervous system release of norepinephrine, causing the stimulatory and hyperadrenergic effects of yohimbine. Antagonism of alpha-2 receptors also inhibits penile smooth muscle contraction and may enhance nitric oxide-mediated smooth muscle relaxation — the combined effects of which promote erection and explain the improvement in ED symptoms after supplementing with yohimbine. Yohimbine also inhibits the activity of alpha-2 receptors on fat cells — where norepinephrine normally acts to suppress fat release. Inhibition of the antilipolytic effect of norepinephrine allows more lipolysis (fat burning) to occur.
