Neem Bark Powder Benefits

Powder made from the bark of the neem tree, Azadirachta indica, has many effects on the human body. According to a 2009 review in the "Nigerian Journal of Physiological Sciences," this nutritional supplement fights parasitic and bacterial infections. It may also benefit people infected with the human immunodeficiency virus. Yet, neem bark powder can cause side effects. Speak with a health-care professional before taking neem extracts.

Heals Ulcers

Stomach ulcers have become a significant medical problem, according to a 2011 review in "Digestion." Some patients remain at risk for serious complications, including mortality. Neem powder has preventative and healing effects on experimental ulcers in animal models. An investigation described in the 2004 volume of "Life Sciences" tested whether neem extracts would show similar effects in human patients. Subjects received neem for 10 days and for 10 weeks in separate studies. The extract reduced gastric secretion -- a known cause of ulcers -- in the shorter study. It reduced healing time in the longer study. Neem did not cause adverse events in either study, but additional research remains necessary.

Inhibits Streptococcus

The streptococcus bacteria causes cavities in healthy teeth. This effect can persist even with the intake of sugar-free products, according to a 2011 review in "Periodontology 2000." Soaking used toothbrushes in a neem-based solution effectively kills the streptococcus present in bristles. An experiment presented in the 2004 edition of the "Journal of Ethnopharmacology" evaluated the impact of neem on plaque -- a film on the teeth caused by streptococcus infection. Volunteers regularly used extracted neem or a mouthwash for six weeks. The neem treatment reduced the amount of plaque. Assays revealed that a reduction in streptococcus mediated these results. Side effects were comparable in both groups.

Reduces Anxiety

Anxiety disorders affect at least 2 percent of the U.S. population, according to the results of a 2005 survey. The report published in "Psychological Medicine" also said that these disorders negatively affect the daily lives of millions. Prescription medications such as benzodiazepines can help treat anxiety, but they often negatively affect activities like driving. A 2010 article in the "West Indian Journal Medical Journal" compared neem to diazepam -- a conventional sedative -- in an animal model of anxiety. Rats received either the herb or the drug during a single testing session. Neem produced comparable results to diazepam on several behavioral tests. Unlike the benzodiazepine, however, the supplement did not impair motor coordination.

Fights Cancer

The prevalence of skin cancer continues to increase despite the greater use of sunscreen. According to a 2010 review in "Clinics in Dermatology," there has been an increased interest in using nutritional supplements for the prevention and treatment of melanoma. An investigation published in the 2011 volume of "Phytotherapy Research" tested the impact of neem bark powder on skin cancer in laboratory animals. Mice with artificially induced melanoma received either extracted neem or no treatment for five months. All of the controls had cancer, while only 58 percent of the animals treated with neem showed signs of melanoma. The mechanisms underlying this cancer preventative effect remain unknown, but neem extracts may kill cancerous cells.