Where it comes from: Aspidosperma quebracho-blanco extract (commonly called quebracho) comes from the bark of an evergreen tree that grows in the northern regions of Argentina. "The primary active ingredient in aspidosperma is yohimbe," explains Roberta Anding, RD, ADA spokesperson and sports dietitian for the Houston Texans.
What it'll do for you: There isn't enough information to know for sure how AQBE works but it has been used around the world to treat asthma, lung disorders, coughs, fevers and other conditions. AQBE, and specifically yohimbe, is most often touted for treating erectile dysfunction and aiding fat loss.
- Erectile dysfunction
In some countries, the extract is used as a prescription drug to treat erectile dysfunction. A 2002 study in Germany found that pro-erectile effects of the bark extract may predominantly be caused by the yohimbe. But it's unclear if the yohimbe is enough on its own to help.
- Fat loss
Yohimbe and other alkaloids in the bark extract are said to block specific receptors that actually inhibit fat loss. A three-week study in 1991 observed 20 obese females on 1,000-calorie diets. They were given 20 mg of yohimbe each day and lost three pounds more than the group receiving placebos. Not a drastic weight loss, but enough to give experts hope that yohimbe can help with weight control. Other studies have found that yohimbe increases the amount of non-esterfied fatty acids, a result of fat breaking down. More research is needed.
Suggested intake: There is not enough information to determine the appropriate range of doses for quebracho. Herbal remedies often suggest dosages of 50-250 milligrams—dosage should depend on your age, health and other conditions.
Some weight loss drugs (such as Hydroxycut Hardcore) contains the extract. If you opt to take them, follow relevant directions on product labels and consult your doctor before using.
Associated risks/scrutiny: "There can be significant side effects including arrhythmia, seizures and high blood pressure," Anding says. People with high blood pressure or kidney disease should avoid products containing yohimbe. There's also some concern about combing the extract with stimulants or antidepressant medications, as it could lead to variations in blood pressure.
"This product has the potential to cause harm and should really be avoided," warns Anding.