Muira puama, also known as potency wood, is a small flowering tree native to Guyana and the Brazilian Amazon. While the dried bark and roots are used to treat central nervous system and inflammatory conditions, muira puama is best known as a traditional remedy for sexual dysfunction. The herb is also reputed to enhance cognitive function. However, peer-reviewed studies on these effects are lacking. Muira puama may also produce side effects. Check with your health care provider before using muira puama.
One of the primary actions associated with this herb is the inhibition of acetylcholinesterase, an enzyme that breaks down acetylcholine into choline in the brain. According to Dr. McGleenon of The Queen’s University of Belfast, the degradation of this neurotransmitter is involved in the development of dementia and other cognitive disorders, including Alzheimer’s disease.
While muira puama may show promise in preventing cognitive decline, be aware that acetylcholinesterase inhibitors are known to produce gastrointestinal problems. In fact, in a paper published in Advances in Psychiatric Treatment, authors Mark Holden and Cornelius Kelly say that this herb should be avoided if there is a history of peptic ulcers.
According to a study published in the May 16, 2002 issue of Phytotherapy Research, compounds in the root of muira puama demonstrate anxiogenic effects, meaning they stimulate the central nervous system. This is why this herb is attributed with increasing physical endurance and mental performance. However, prolonged use or high doses of muira puama preparations may promote anxiety and insomnia, as well as increase blood pressure.
It should also be noted that the authors of this study compared the stimulatory effects of muira puama with pentylenetetrazol, a drug shown to improve memory and learning in mice bred to model symptoms of humans with Down syndrome. The drug works by inhibiting another neurotransmitter called GABA. However, the U.S. Federal Drug Administration banned this drug in the 1980s due to its causing seizures in some people, a known side effect of GABA inhibition. If it can be shown that non-epileptic doses of this drug can be administered successfully without causing seizures, research is likely to continue on the use of GABA inhibitors in treating Down syndrome and other cognitive disorders. Until then, it’s reasonable to caution that muira puama may also act as a GABA inhibitor and potentially produce seizures in certain people. Certainly, you should not use this herb if you are taking anti-seizure medications.
Possible Drug Interactions
Another team of researchers published the results of a study in Phytotherapy Research in 2009 that indicated that muira puama may impact levels of dopamine, noradrenaline and serotonin in the brain, producing antidepressant-like effects. This means that you should not take preparations made from this herb if you are taking anti-depressant medications.
- “British Journal of Clinical Pharmacology”; Acetylcholinesterase Inhibitors in Alzheimer’s Disease; B.M. McGleenon, et al.; October, 1999
- "Advances in Psychiatric Treatment"; Use of Cholinesterase Inhibitors in Dementia; Mark Holden, Cornelius Kelly; 2002
- "Phytotherapy Research"; Anxiogenic properties of Ptychopetalumolacoides Benth (Marapuama); da Silva, et al.; May, 2002
- "Scientific American"; Drug May Counteract Down Syndrome; J.R. Minkel; February, 2007
- "Phytotherapy Research"; Antidepressant profile of Ptychopetalum olacoides Bentham (Marapuama) in mice; Piato, et al.; April, 2009