Eurycoma longifolia, also known as tongkat ali, may enhance sexual virility and performance and is often used to treat erectile dysfunction, according to WebMD. It is also used for body building, reducing body fat and enhancing athletic performance. Research suggests tongkat ali may increase testosterone in the body.
Tongkat ali is sometimes used to treat fevers, malaria and ulcers. It may also be used for diarrhea, bone pain, coughing and syphilis. Some people take it to treat high blood pressure, tuberculosis, headaches, coughing and cancer, states WebMD. Scientific research on tongkat ali is ongoing, and many health claims are not backed by confirmed data, as of 2015.
Some evidence suggests tongkat ali may increase sperm concentration in men, and it may improve sperm quality, notes WebMD. Some people use it to increase interest in sex and to increase libido. Men with low testosterone levels may take tongkat ali for one month to improve symptoms related to low testosterone levels. Research suggests that taking tongkat ali for five weeks while engaging in an intense strength-training program may cause an additional increase in muscle mass.
Because there is not enough information available to determine appropriate dosage levels, it is important to speak to a health care professional before taking tongkat ali. Dosage levels are determined by a number of factors, including age and health, explains WebMD.