Safety reading

Hidden Drugs In Sexual Enhancement Supplements: What A Decade Of FDA Warnings Found

A supplement panel lists what the maker chose to declare. The FDA warnings for this category are about what was not declared. Here is what a decade of them found, why it matters medically, and what a panel can and cannot rule out.

By VigorHorse Team · Last updated September 26, 2026 · 11 min read · Safety reading

The problem is specific to this shelf

Most supplement safety writing worries about the ingredients that are on the label. This article is about the ones that are not.

In 2018, a group of researchers published an analysis in JAMA Network Open of every warning the FDA had issued about adulterated dietary supplements from 2007 through 2016. Their source was the agency's own Tainted Products Marketed as Dietary Supplements database. After removing duplicates issued within six months of each other, they counted 776 adulterated products and 146 companies.

From the 2018 analysis. A later published correction fixed two drug names in the text, a figure key and an author affiliation; it did not change the counts quoted here.

Read down that table and the pattern is hard to miss. Sexual enhancement is the biggest single category, and its most common hidden ingredient is sildenafil, the active drug in a well-known prescription medicine for erectile dysfunction.

What was found inside

Sildenafil itself turned up in 166 of the 353 sexual-enhancement products. Another 134 contained at least one structural analogue of it, an unapproved chemical cousin. Combined, that is 287 of 353 products, or 81.3%, containing sildenafil, an analogue, or both. A fifth of all the adulterated products, 157 of 776, contained more than one unapproved ingredient.

The analogues are the part that shows this is not a matter of a few careless factories. A 2014 review of the analytical chemistry counted more than 50 unapproved analogues of the prescription drugs in this class found as adulterants in the literature. Its authors describe the people making these products as investing time and resources to synthesise exotic analogues and devise new ways of adulterating, specifically to avoid detection by standard screening. A drug that nobody has ever tested for is, from the seller's point of view, a drug that cannot be found.

That is why this problem is hard to see from the outside. A tablet or gummy carrying an analogue looks like every other product in the same aisle, and a marketing panel that omits it looks exactly like one that omits nothing.

A warning does not end the story

The most unsettling number in that paper is not about the first warning. Twenty-eight products were named in two or three separate warnings, more than six months apart. Of those, 19, which is 67.9%, were reported to contain new unapproved ingredients the second or third time. The authors read this as the FDA finding the same product adulterated more than once.

The paper also says where the samples came from in recent years. Between 2014 and 2016, 117 of 303 adulterated samples (38.6%) were identified through online sampling, and 104 (34.3%) through examination of international mail shipments. Put those two together and they account for 221 of 303, roughly seven in ten of the samples in those years.

None of that says the internet is unsafe or that mail is suspect. What the numbers do suggest is that the parts of the supply chain furthest from a named seller, a phone number and a return address are where most of the samples in those years were found.

Why an undeclared drug is a medical problem, not a technicality

It is easy to hear “contains sildenafil” and think it means the product simply works. The reason regulators care is different, and it sits in cardiology, not in marketing.

A 2018 review in the Journal of Cardiovascular Pharmacology and Therapeutics sets it out plainly. Drugs of this class are vasodilators. So are nitrates, which are used for angina and heart failure. Taken together they can have synergistic effects that enhance the fall in blood pressure. For that reason the prescription drugs are contraindicated in men taking organic nitrates, and the review describes a waiting period, generally 24 hours after a short-acting one and 48 hours after a long-acting one, before nitrates may be taken.

Now read the 2018 analysis's own concern. It says drug ingredients in these supplements have the potential to cause serious adverse effects through accidental misuse, overuse, or interaction with other medications, underlying health conditions, or other pharmaceuticals in the same supplement.

Put the two together. A man taking a nitrate for his heart is the person for whom an unexpected vasodilator is most dangerous, and he is also the person least able to know he has swallowed one, because it is not on the label. That is why the issue is one for cardiologists and pharmacists as much as for the FDA, and why it is worth telling your doctor or pharmacist what you take, supplements included.

What those numbers do not say

The figures above are striking enough that they are easy to over-read, so here are the limits, stated once.

• They count warnings, not products on shelves. The FDA warns about products it has found. The analysis cannot say what share of all sexual-enhancement supplements are adulterated, only how many were caught.
• They end in 2016. The paper says nothing about what has happened since, in either direction.
• They do not amount to a verdict on any brand, and nothing in this article suggests one about VigorHorse or any product on this website.
• They are about hidden drugs, not about the safety of declared botanicals, which is a separate literature covered in the ashwagandha and other articles on this blog.

What a printed panel does and does not rule out

Here is the part that matters for this jar. The VigorHorse panel is a complete one: serving size, six nutrition rows, a proprietary blend line at 82 mg listing nine names, and an other-ingredients line. Every name on the blend line is a plant extract, an amino acid or caffeine. No prescription drug is among them.

That is a fact about what was declared, and it stops there. An undeclared ingredient, by definition, is not on the panel, so the panel cannot rule one out. The only thing that can is an independent laboratory assay of the actual lot, and it is important to be direct about this: the batch verify page states that the lot reference and the certificate reference held for this stock are filing references, not laboratory results. This website does not publish an assay for this lot, and nothing here should be read as claiming one.

The same limit applies to every supplement in the aisle. It is not a special weakness of this one, and it is worth knowing about all of them. The testing and quality page makes the related point that the seals on the jar describe a factory, a filing and a supply chain, and none of them is a measurement of a gummy.

One observation that leans the other way, and is not proof

Everything the seller and this website say about VigorHorse describes a slow product. The results timeline page says nothing on the panel is built to be felt on the first day, and the seller's own review summary lists slow starts as the commonest complaint, with a typical wait of four to eight weeks. A product hiding a fast-acting prescription drug would be expected to behave and be described very differently. It is a fair observation about how the jar is presented. It is not an assay, and it does not replace one.

What an independent test would have to do

If a printed panel cannot answer the question, it is fair to ask what could. The analytical-chemistry review is useful here because it explains why “we tested it” is not a single thing.

Finding a known drug in a gummy is one job. Finding an analogue nobody has catalogued is another. The review lists the techniques that laboratories use to detect and characterise these adulterants: high-performance liquid chromatography, gas chromatography with mass spectrometry, liquid chromatography with mass spectrometry, nuclear magnetic resonance, vibrational spectroscopy, ion mobility spectrometry, immunoassays and several more. It says the rapid identification of unknown analogues is greatly helped by having a wide range of them, and it describes the challenge of detecting exotic analogues designed to slip past standard screens.

For a buyer, that translates into three practical questions to put to any seller who says a product has been tested.

1. Was the test looking for prescription drugs and their analogues at all, or only for heavy metals, microbes and label-claim potency? A clean result on the second list says nothing about the first.
2. Which method was used, and can the laboratory identify a compound it was not told to look for?
3. Is the report for this lot? A certificate for a different production run describes a different run.

Those are the questions the batch verify page is honest about not answering, and they are the questions worth asking of the whole category rather than one jar. It is also worth remembering the point made on the testing and quality page: the agency does not approve dietary supplements before they go on sale, so nobody is doing this work on your behalf unless a seller chooses to commission it.

What an honest seller can publish

There is a short list of things a seller can put in front of you, and it is useful to see which of them this website does. A complete panel: yes, transcribed row by row. A lot reference and an artwork revision: yes, with the caveat that they are labels rather than test results. A phone desk and a return route: yes, with a sixty-day window. An independent assay of the lot for prescription drugs and their analogues: no, and the pages say so. Publishing the absence is the point. A page that quietly implied a test it did not hold would be doing exactly what the FDA analysis worries about, with better formatting.

Even declared botanicals come with reports

For balance, it is worth reading the paper that goes the other direction. A 2014 review in BioMed Research International looked at 203 websites, drug forums and other online resources, and identified the most common sexual-enhancement products for sale online. The active constituents it named were yohimbine, maca, horny goat weed and Ginkgo biloba. It reports that these substances have been associated with adverse events and with psychological symptoms such as mood changes, anxiety, hallucinations and addictive behaviours, and it calls the uncontrolled availability of such products a public health concern.

Two of those four names, maca and horny goat weed, are on this jar's blend line. The paper is a review of online sources and case literature. It counts reports, not rates, and it cannot say how much of any ingredient was involved. Nothing in it says that a total of 82 mg shared between nine names produced any of those events. What it does say is that a botanical on a label is not automatically harmless, and that the honest response to an unexpected symptom is to stop and ask a professional. The VigorHorse label says to discontinue use and consult your doctor if any adverse reactions occur.

A 2015 urologist's guide to the top-selling men's sexual health supplements makes a related point about format. The best sellers it reviewed were blends of multiple ingredients, with up to 33 in a single formulation, and the medical literature on the efficacy of those ingredients was generally of low quality. A long blend makes it harder for anyone, including a doctor, to say what caused what.

Seven checks before you open any jar in this aisle

The right-hand column of this table is the article's own synthesis of the sources above.

None of these checks is exotic, and none of them needs a laboratory. Together they close most of the gaps a printed panel leaves open, and the one they cannot close, an independent test of the specific lot in your hand, is the one worth asking every seller in this category about.

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