By Ed Cara
An ingredient commonly found in dietary supplements is often times improperly labeled and fraudulently marketed as “natural,” according to a new study published Tuesday in the journal of Drug Testing and Analysis.
Sifting through the contents of 49 different dietary supplement brands, the study authors concluded that the quantity of yohimbine, a supposed aphrodisiac extracted from the yohimbe tree, is rarely displayed accurately on the accompanying label, if at all. Troubling still was their discovery that these brands frequently contain high, pharmaceutical levels of yohimbine, but seldom include information about the chemical’s side-effects.
“If safe consumption of a product requires that both accurate quantity as well as known adverse effects be provided on the label, then only 4.1% of the yohimbine supplement brands analyzed provided sufficient safety information for consumers,” the authors concluded. “This is a particularly concerning finding given that many countries have already banned yohimbine from all over-the-counter products due to its potential serious health effects.”
To conduct their study, the authors purchased supplements known to be stocked in seven major retail chains across five different states, including CVS, Rite Aid, and Vitamin Shoppe. Though yohimbine, an alkaloid, exists in nature, it was once often prescribed to patients as a means of aiding erectile dysfunction or low libido — a souped up version known as yohimbine hydrochloride (HCI). Due to its “limited efficacy for sexual dysfunction and significant adverse effects including headaches, hypertension, and panic attacks,” and the advent of drugs like Viagra, however, yohimbine HCI fell out of favor among the mainstream medical community.
That hasn’t stopped supplement manufacturers from adding yohimbine, supposedly the “natural”, weaker version, to their products, intended as either sexual or sports enhancement, according to the authors. As they go on to note, adding the synthesized, pharmaceutical version of yohimbine to a supplement, legally considered a food by the FDA, is actually illegal under US law. And yet, that’s exactly what they found evidence of in 39 percent of the supplements tested, explaining that natural yohimbe bark extract contains two other alkaloids, rauwolscine and corynanthine, in addition to yohimbine — neither of which were found in those select products.
“This suggests that the yohimbine in these products may be highly refined from P. johimbe(yohimbe) bark extract or synthetically produced,” they wrote.
Additionally, the supplements had wildly varying amounts of yohimbine per pill, from 0 to 12.1 milligrams, the latter dose 21 percent stronger than what’s available in the prescription version.
Though the authors only had the opportunity to test one bottle of a particular brand each, they felt that their findings have further illuminated the reality that dietary supplements are poorly regulated and mistakenly assumed to be safer than conventional drugs. Left unanswered is whether any of the other ingredients found in these supplements — the authors noting that the majority contain more than 5 — are similarly mislabeled or potentially dangerous.
“While dietary supplements often contained pharmaceutically relevant quantities of yohimbine, the supplement labels very infrequently provide consumers with accurate information regarding quantity of yohimbine or known adverse effects,” the authors wrote. “Our study demonstrates that consumers in the USA are unable to obtain adequate safety information from the overwhelming majority of yohimbine supplement brands offered for sale by seven mainstream retailers.”
Source: Cohen P, Wang, Y-H, DeSouza R. Pharmaceutical quantities of yohimbine found in dietary supplements in the USA. Drug Testing and Analysis. 2015.