With brightly colored packaging and claims of enhancing sexual performance, coupled with names like “Rhino”, “Anaconda”, and “Magnum”, products designed to boost sexual function are hard to ignore. They can be purchased online, at convenience stores, and gas stations, and some can even be ordered through delivery services.

But what's inside the package may be quite different from what's written on the label.

In May 2023, the U.S. Food and Drug Administration (FDA) warned consumers not to use a sexual performance enhancement product named Rhino 7S Type F3 7000, which is one of many products from the Rhino brand. Laboratory tests revealed that this product contained two ingredients that were not listed on the label: sildenafil (sildenafil), the active ingredient in the prescription erectile dysfunction drug Viagra (Viagra); and acetaminophen (acetaminophen), which is also the ingredient in the common pain reliever Tylenol (Tylenol).

This discovery is not an isolated case.

As early as 2007, FDA began to maintain a growing list of health fraud schemes, which included sexual enhancement and stimulant products that were found to contain hidden drug ingredients.

Today, the market for sexual performance enhancement products continues to grow, and counterfeit products continue to emerge. In September 2026, another 7 new products were added to the FDA list. Recent warnings have covered pills, gummies, honey products, coffee, and even chocolate that is advertised as a sexual performance enhancer.

As a public health researcher who studies the use of substances related to unregulated products and health behaviors, I believe these products reflect a larger challenge: the mismatch between global supply chains, online commerce, and regulatory systems, which struggle to keep up with rapidly changing products.

Health supplements are regulated, but the approach is different from that of prescription drugs.

In the United States, the regulatory framework for dietary supplements, as indicated by FDA, is different from that for prescription and over-the-counter drugs. Drugs undergo a rigorous application process that typically includes three phases of clinical trials, and the entire process often takes nearly a decade.

Supplements, on the other hand, are regulated by the Dietary Supplement Health and Education Act of 1994, which requires manufacturers to ensure that their products are safe and that the labels are accurate. Therefore, dietary supplements are not completely unregulated, but they generally do not undergo the same level of FDA approval before being marketed as drugs do. This means that FDA does not approve the safety and effectiveness of these products before consumers have access to them, as is the case for drug approvals.

This creates an important distinction between medications like Viagra and many products sold under the guise of dietary supplements, such as the sexual function enhancement products of many Rhino brands. Viagra is a prescription drug approved by FDA; its active ingredient, sildenafil, has been evaluated for safety, efficacy, dosage, and production quality in clinical trials, and has been approved for specific medical uses.

After dietary supplements are launched on the market, FDA will regularly inspect their production facilities and collect and test some of the products. However, FDA does not conduct routine testing on every supplement on the shelves. Instead, the agency prioritizes products related to diseases or injuries, as well as those suspected of containing fraudulent, adulterated, or other illegal ingredients.

The hidden Viagra – and more problems

Sildenafil and tadalafil (tadalafil) are the active ingredients of Viagra and Cialis (Cialis) respectively, and belong to a class of drugs known as phosphodiesterase type 5 inhibitors. They can effectively treat erectile dysfunction when prescribed appropriately.

However, taking these medications without knowledge is completely different from taking them under a doctor's supervision. It is known that they can interact with nitrate drugs, including nitroglycerin used by some patients with heart disease. The combination of the two may lead to a dangerous drop in blood pressure.

Rhino Case 7S also presents another risk: unlisted acetaminophen. It is currently unclear why acetaminophen appears in this supplement and how it got mixed into it. If someone takes this supplement while also using Tylenol, cold medicine, or other products containing acetaminophen, they may exceed the recommended dose without knowing it. Excessive intake of acetaminophen can lead to severe liver damage and, in extreme cases, may even cause acute liver failure or death.

Research shows that adulteration is not limited to just a few easily identifiable drug components. A scientific review in 2023 found that between 2003 and mid-2023, 112 types of unapproved phosphodiesterase type 5 inhibitors and related compounds were detected in products intended to enhance sexual function, all of which are considered adulterated ingredients. Adulterated supplements may contain approved drugs, unapproved analogs, as well as other modified compounds.

A global market

This is not just a problem in the United States. Researchers have discovered unlisted erectile dysfunction medications in supplements sold in Europe, Asia, the Middle East, and other regions.

In a study of 158 sexual function enhancement supplements in the UAE, researchers found that over 12% of the samples contained unlisted sildenafil, tadalafil, or vardenafil ( vardenafil ).

The World Health Organization warns that the increasingly complex international supply chains and the growth of e-commerce have made it particularly difficult to control substandard and counterfeit health products. Producers of these products may purchase raw materials in one country, manufacture or package them in another, and then sell them to consumers thousands of miles away through the internet.

Illicit drug trade on a global scale is a major issue. From December 2024 to May 2025, Interpol organized the “Pangea XVII” operation, during which law enforcement agencies from 90 countries seized over 50 million doses of illicit drugs. Medications for erectile dysfunction were the second most commonly seized product category, following psychostimulants. Psychostimulants refer to drugs that affect the way the brain regulates dopamine.

In the following year, another international law enforcement operation targeted approximately 13,000 websites, social media pages, channels, and automated bot programs related to the sale of illegal drugs. Medications for erectile dysfunction were once again among the most frequently seized products.

Catch-up regulation

However, identifying one dangerous product does not eliminate the entire market. Packaging can be changed, products can disappear only to reappear under a new name, and sellers can shift from one website or social media account to another. Manufacturers may also alter the chemical composition of the products.

Researchers tracked a sexual performance enhancement supplement named “POWER” from 2007 to 2022 and found that every version they tested contained type 5 phosphodiesterase inhibitors, although the specific ingredients used varied over time. Despite warnings issued by European food and health authorities and seizures of the product, it was still being sold online at the end of the study period.

Therefore, it is crucial to conduct laboratory tests on supplements, but testing alone cannot solve the problem. FDA also acknowledges that its publicly listed warning list only represents a small portion of the contaminated products that are currently on sale. In other words, the fact that a product does not appear in the FDA database does not mean that it is safe.

A persistent problem

Words like "natural," "herbal," or "dietary supplement" may lead consumers to believe that a product intended to enhance sexual function does not contain any medicinal ingredients. However, this may not necessarily be the case.

U.S. law requires that when supplement manufacturers make claims about the functions of their products, they must include a specific FDA disclaimer; however, the law does not require that sexual function enhancement supplements carry warnings indicating that "natural" or "herbal" products may contain unlisted medicinal ingredients. Therefore, the labeling regulations for FDA are not specifically designed to alert consumers to these hidden medicinal components in these products.

Online sales add another layer of complexity. According to federal law, some online platforms are required to verify the identity information of certain high-volume third-party sellers and provide consumers with a mechanism to report suspicious platform activities. However, the law generally does not require platforms to check whether dietary supplements contain hidden drug ingredients, nor does it require them to proactively report each product that may be adulterated to FDA.

It's easy to understand why these products are attractive: they provide private, convenient, and widely available solutions to many difficult-to-discuss male health issues. However, this convenience also conceals a fundamental problem: consumers have almost no reliable way of knowing whether the ingredient list on the packaging matches what is actually inside.

For sexual health products, reducing this uncertainty depends not only on regulation and monitoring but also on making conversations about sexual health more commonplace, so that people have safer channels to seek help.

The Conversation contacted RhinoPills to seek comments, but there was no response from the other party.

Andrew Yockey, Assistant Professor of Health and Kinesiology at the University of Illinois at Urbana-Champaign

This article is reprinted under the Creative Commons License by The Conversation. The original text can be read here.