Erectile Dysfunction Internet Pitches Called Risky by FDA

ROCKVILLE, Md., July 17 -- Beware the smooth-tongued Internet pitchmen touting so-called "dietary supplements" that allegedly treat erectile dysfunction and enhance sexual prowess, the FDA has warned consumers.

Specifically, the agency cited seven alleged supplements that "are in fact illegal drugs that contain potentially harmful undeclared ingredients." The FDA warned against buying or consuming the dangerous seven, all unapproved. They are Zimaxx, Libidus, Neophase, Nasutra, Vigor-25, Actra-Rx, and 4EVERON. "There is no guarantee of their safety and effectiveness, or of the purity of their ingredients," said the FDA.

The FDA said its chemists analyzed the drugs and found that one, Zimaxx, contains sildenafil, the active ingredient in Viagra, and that the others contain chemical analogs to sildenafil or to vardenafil, the active ingredient in Levitra. None of the product labels mentions the presence of these ingredients, the FDA noted.

"These products threaten the public health because they contain undeclared chemicals that are similar or identical to the active ingredients used in several FDA-approved prescription drug products," said Steven Galson, M.D., director of FDA's Center for Drug Evaluation and Research. "This risk is even more serious because consumers may not know that these ingredients can interact with medications and dangerously lower their blood pressure."

Sildenafil and vardenafil are selective inhibitors of 5-phosphodiesterase (PDE5), an enzyme that degrades the second-messenger molecule cyclic guanosine monophosphate (cGMP), which is chiefly responsible for the smooth muscle relaxation of blood vessels in the corpus cavernosum of the penis.

PDE5 inhibitors also affect the nitric oxide/cGMP pathway in blood vessels in the cardiovascular circulation and may potentiate the blood-pressure lowering effects of nitrates used to treated angina.

In fact, Viagra was originally developed as an anti-angina agent. Its effect on erectile function was discovered serendipitously, when investigators noticed that men involved in the original clinical trials were reluctant to return their unused medication.

The FDA warned that men with diabetes, hypertension, high cholesterol or heart disease often have erectile dysfunction and may be also be taking nitrates, unaware that there could be seriously or potentially fatal drug interactions with the hidden ingredients in the mail-order drugs.

The FDA said it sent official warning letters to the firms marketing the illegal products. The letters stated that the products are illegal drugs based on claims made for the products or their ingredients, and that the product labels are false and misleading because they fail to list all of the ingredients.

The FDA has instructed agency staffers to stop the importation of Libidus from Malaysia, and the agency recently stopped a shipment of 4 EVERON from entering the United States.

The Web site for, Libidus, based in Kuala Lampur, states that "it has come to our attention that a recent laboratory test of Libidus indicated that there was unlisted ingredients found in the product and therefore have made the decision to immediately stop marketing the product until such time as it can be determined how these unlisted ingredients found their way into the product and assurance that the product is once again 'all natural'."

The FDA, which in recent years has been criticized for being lax in its oversight of over-the-counter drugs, herbal products, and dietary supplements, recently undertook a survey and analysis of 17 dietary supplements hawked on the Internet for the treatment of erectile dysfunction and enhancement of sexual performance in men.

"Our survey found that many of the so-called 'dietary supplements' marketed as treatments for erectile dysfunction actually contain non-dietary chemicals, including chemicals used as active ingredients in FDA-approved drugs," said Margaret O'K. Glavin, FDA's associate commissioner for regulatory affairs.