(CNN) Consumers, especially men, should not purchase or use two e-cigarette liquids that contain popular erectile dysfunction drugs, the Food and Drug Administration warned Tuesday.

The two HelloCig e-liquids contain tadalafil and sildenafil, the main ingredients in two of the most popular male enhancement drugs on the market, the FDA said. "These FDA-approved prescription drugs are not approved for inclusion in e-liquid products sold over the counter and are therefore being sold illegally."

By not properly labeling the e-liquids, the agency said, the company was not providing adequate warnings for the protection of users, specifically anyone with erectile dysfunction, high blood pressure, diabetes, high cholesterol or heart disease who take nitrates to manage their condition.

"These undeclared ingredients may interact with nitrates found in some prescription drugs such as nitroglycerin and may lower blood pressure to dangerous levels," the FDA said in its warning.

A lab analysis found both sildenafil and tadalafil in E-Cialis HelloCig E-Liquid and sildenafil in E-Rimonabant HelloCig E-Liquid, both sold by Shanghai-based HelloCig Electronic Technology Co. Ltd.

The company has not responded to a request for comment.

Although no adverse events have been reported to the agency, all consumers should stop using the products immediately, the FDA said, and anyone who experiences side effects should report them to the FDA's MedWatch Adverse Event Reporting program.

The FDA says it sent a warning letter to HelloCig in October, citing a number of concerns about illegal marketing claims. HelloCig was misbranding and selling its products in the United States as an "FDA approved product with FDA," in violation of federal rules.

"FDA recently warned HelloCig of these issues and contacted the company several times to recommend they recall these products due to the risks to consumers. However, HelloCig has not responded to the agency's recommendation," the agency said in its warning.

Bottles of E-Cialis HelloCig E-Liquid were sold with an image of a Cialis bottle and tablets, while advertisements on Twitter and Tumbir showed "a partially undressed couple embracing," the FDA says. The caption states, "WOOOOW, Have you tried our E-Cialis? It is amazing LOL."

Though E-Rimonabant HelloCig E-Liquid contains the same active ingredient as Viagra, the FDA said HelloCig was marketing it with an image of an Acomplia container and tablets.

"Acomplia is the tradename of the anti-obesity drug product in Europe," the FDA warned. "Using the tradename of the drug product Acomplia and including an image of the Acomplia container and tablets next to the product on your website suggests that the product is intended to treat obesity."

HelloCig did not respond to the initial warning, the FDA said.

The manufacturers of Cialis has not responded to requests for comment. The maker of Viagra had no comment.