Yohimbine is a constituting alkaloid of inner barks of a specific tree named Corynanth yohimbe, found to be growing in southern Africa. Alkaloids obtained from this tree have been studied in great detail, while Yohimbe has been employed in use as an aphrodisiac for ages. It is most commonly used for veterinary purposes and for treatment of erectile dysfunction, though it has also been used to treat obesity.
Even though Yohimbine has not been studied completely for its utilisation in battling obesity, the data that currently exists shows that it has much potential. In 1991, a study spanning a duration of 3 weeks, held on 20 obese women on strict 1000 calorie diet showed that a daily dose of 20 mg of yohimbine increased the weight loss by 3 lbs. In addition, many studies have discovered that yohimbine leads to an increase in the non-esterified fatty acids or NEFAs, which is a product of lipolysis i.e. breakdown of fat, in lean as well as obese people. It also suppresses appetite.
Yohimbine blocks the alpha adrenoreceptors. Our body has many feedback mechanisms which prevent norepinephrine or NE from being released. NE is a major hormone inducing fat loss in our body. Release of NE stimulates alpha as well as beta adrenoreceptors. While beta adrenoreceptors result in breakdown of fat, alpha adrenoreceptors work in entirely opposite way. By blocking alpha adrenoreceptors, yohimbine inhibits the negative effect leading to increased fat loss. It also increases the flow of blood in fat tissues, preventing retention and accumulation of fat.
Yohimbine is a sexual stimulant, too, and utilised in treating erectile dysfunction in men, while in women, combined with L-arginine glutamate, it has been shown to increase sexual arousal in women suffering from its absence. It even increases the level of serum testosterone in men.