Study: Dangerous levels of levodopa found in certain botanical supplements

A new study found botanical supplements of mucuna pruriens, a tropical legume, contained high levels of levodopa that could harm health -- and "unpredictably complicate" management of Parkinson's disease. Photo by Astralek/Wikimedia Commons
A new study found botanical supplements of mucuna pruriens, a tropical legume, contained high levels of levodopa that could harm health -- and "unpredictably complicate" management of Parkinson's disease. Photo by Astralek/Wikimedia Commons

Aug. 8 (UPI) -- Mucuna pruriens, a bean that naturally contains traces of levodopa, or L-dopa, which converts into dopamine in the brain, has been long used in Ayurvedic medicine for issues ranging from male infertility to depression.

But a new study warns that Mucuna supplements were found to contain highly elevated levels of levodopa that could harm health -- and "unpredictably complicate" the treatment of Parkinson's disease.


In fact, in botanical supplement products that listed a specific quantity of M pruriens seed extract on the label, the researchers found that the actual quantity of levodopa was 228% to 2,186% greater than the estimated quantity.

That's according to a research letter published Monday in JAMA Neurology.

"These dramatic findings are a reminder that there is no real difference between a 'botanical' supplement and a pharmaceutical drug," Dr. Pieter A. Cohen, the study's lead author, told UPI in an email.


Cohen said traditional botanicals have "potent components," and "if those are amplified in the supplement, then the supplement pill is no different than a prescription pill except for one very important difference -- the supplement contains an unpredictable amount of the drug."

Cohen said the researchers have described this previously in studies of botanicals that contain prescription drugs to lower cholesterol or to treat erectile dysfunction.

An associate professor at Harvard Medical School and an internist at Cambridge Health Alliance, a Harvard-affiliated safety-net health system, Cohen said he was surprised by the findings.

"I was shocked that we found amounts of levodopa in these purportedly 'natural' supplements that often exceeded many prescription formulations of levodopa," he said.

The supplement in question is sometimes referred to as "dopamine bean" or "dopa mucuna" and is marketed ... for its dopamine effects, to help with mood, workouts, focus, energy -- you name it," Cohen said.

Cohen said he became interested in Mucuna supplements "when concerned parents shared that they believed their son was having serious psychiatric effects from the supplements," and he wouldn't stop using them.

This led the researchers to design a study to find out exactly what was in the supplements by comparing the amount of the prescription dopamine precursor levodopa in supplements found in the National Institutes of Health's database to extracts of the actual bean.


"Some supplements contained more than twice as much levodopa than found in many prescription-only formulations," Cohen said.

Given the findings, he said it's imperative for consumers and doctors to know "that nothing prohibits 'botanical' supplements from being formulated into potent prescription-type drugs -- and when this happens, the risks to consumers are unpredictable."

According to Cohen, one step that consumers can take is to avoid supplements that promise to improve mood, brain function or calm the body.

"These claims might be hints that unpredictable dosages of drugs are actually in the bottle," he said.

According to Cohen, the issue of when the pill simply becomes levodopa and regarded as a pharmaceutical is a key question.

"For me, these products are no different than pharmaceutical drugs," he said, "except for a very important difference: that they are inaccurately labeled and neither the consumer nor their doctor know how much of the medication they are actually putting into their body."

He points out there are many complicating issues.

One possibility is that someone is worried they have Parkinson's disease and begins taking the supplement on their own. "This would certainly complicate the diagnosis of Parkinson's or other neurologic diseases and may hamper the patient receiving timely, proper care for their condition," Cohen said.


Another possibility is that patients take these pills along with prescription levodopa. "In this case their doctor is not aware of how much levodopa the patient is actually getting," he said, "and these higher-than-prescription amounts of levodopa could lead to serious reactions including agitation, paranoia, psychosis and impulse control problems such as excessive gambling."

Cohen sees it as likely that the large amounts of dopamine got into the supplements in a calculated manner.

"In this case -- because of other details on the label -- it's clear that the manufacturers were signaling that they were increasing the potency of these botanicals," Cohen said. "So, my guess would be that it is intentional, although I have no definitive proof of that."

Yet, he said, the more pressing question is how it was done.

"Do we think the manufacturers took kilograms of beans and then isolated the levodopa? Or do we think the manufacturers purchased mass-produced levodopa as a chemical from a factory and poured it into the supplement? I would imagine that the second approach would be more economical so would seem to be more likely," he said.

Cohen said the researchers will be discussing these results with the Food and Drug Administration, which loosely regulates dietary supplements on the food, not the drug, side under a 1994 amendment to the federal Federal Food, Drug and Cosmetic Act.


The researchers acknowledged the study's limitations. Only two authenticated samples of M pruriens seed extracts were analyzed, and they said it is possible that different variants of M pruriens or different extraction methods might affect the quantity of levodopa.

Also, they said, only one sample of each brand of supplement was analyzed, and it remains unknown if the dose of levodopa varies from batch to batch over time.

Given these findings, the scientists urged clinicians to try to identify unsuspected levodopa consumption by asking patients directly about the use of supplements.

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