Some herbal pills hide prescription drugs, and others swap out the herb

Key takeaways

• From 2007 through 2016, FDA warnings flagged 776 supplement products spiked with drugs, and nearly all were sold for sex, weight loss or muscle building¹.
• Hidden erectile dysfunction drugs can push blood pressure dangerously low in people who take nitrates such as nitroglycerin².
• When researchers bought recalled supplements online years later, two out of three still held banned drugs³.
• An industry-supported 2024 review found that about 57% of tested ginkgo samples and 42% of black cohosh samples were adulterated or mislabeled⁴.
• Search FDA’s health-fraud lists before you buy a high-risk product, but don’t treat a clean search as proof of safety, because the FDA says its lists catch only a small share⁵.

Between early February and early April 2026, six chocolates, honeys and syrups were recalled in the United States because they held hidden drugs⁶. Each contained sildenafil, tadalafil or both⁶. Those are the active ingredients in Viagra and Cialis².

None of the labels said so.

The same FDA recall list for 2026 includes capsules for joint aches that held meloxicam, a prescription anti-inflammatory, and capsules that held the steroid dexamethasone⁶. It also includes products sold as tejocote root that contained yellow oleander, a poisonous plant⁶¹⁴.

Products like these often wear the words “herbal” or “all natural.” The FDA warns that those words don’t guarantee safety⁵.

For people who choose plants because they value purity, that’s a betrayal of the very thing they’re paying for. The good news is that the worst problems cluster in a few kinds of products. Once you know where they hide, a few habits help you steer around them.

Adulteration comes in two forms, with different motives

The first form is drug spiking. Someone adds a pharmaceutical so the product delivers a strong, fast effect that buyers will notice. The FDA has said that products with undeclared drug ingredients generally fall outside the legal definition of a dietary supplement and may be regulated as drugs⁷⁸.

The second form is economic adulteration. The U.S. Pharmacopeia, a standards group, defines it as secretly adding fake ingredients, or removing or replacing real ones, for the seller’s profit⁴. Think of a cheaper plant, a dye or a pure chemical standing in for an expensive herb.

Both kinds thrive for the same reason. Supplements reach shelves without FDA approval, and the agency doesn’t test them before they’re sold⁷. Our history of natural health explains how the 1994 supplement law set up that system. Our guide to why supplement labels say “supports” covers the rules on claims.

Hidden drugs cluster in three kinds of products

In 2018, researchers at the California Department of Public Health’s Food and Drug Branch published a study of FDA’s tainted supplements database¹. From 2007 through 2016, FDA warnings named 776 adulterated products from nearly 150 companies¹.

Three categories made up almost all of them¹:

• Sexual improvement: 45.5% of products. Sildenafil turned up in 47% of these.
• Weight loss: 40.9%. About 85% of these held sibutramine, a diet drug.
• Muscle building: 11.9%. Steroids or steroid-like ingredients appeared in 89%.

About one in five products held more than one drug. And 97.6% didn’t list the drug on the label at all¹.

Where does the FDA find them? Among flagged products from 2014 to 2016 with a recorded source, about 39% came from online sampling and about 34% from screening international mail¹.

The disguises keep changing. The FDA has posted notices on 24 honey-based products with hidden sildenafil or tadalafil². They were sold through sites including Amazon, eBay, Etsy, AliExpress and Walmart².

The FDA’s current consumer advice widens the circle. It flags products sold for sexual improvement and energy, weight loss, pain, bodybuilding or sleep⁵. It also notes where they turn up: gas stations, convenience stores, supplement shops, salons, spas and social media ads⁵.

A 2024 study in JAMA Network Open looked at products marketed to service members. Researchers bought 30 weight-loss supplements online from 12 companies that offered military discounts⁹.

Labels were inaccurate for 25 of them. Seven held ingredients not on the label, including 1,4-DMAA and yohimbine. None carried a third-party certification⁹. The work was funded by two military health programs, the Consortium for Health and Military Performance and Operation Supplement Safety⁹.

A hidden drug is risky even when it “works”

A product that claims to work like a prescription drug may be doing exactly that, without the prescription’s safeguards. Tainted products carry none of the warnings or contraindications that come with the real drug¹. You don’t know the dose, and you may get two drugs at once.

The risks depend on the drug:

• Sildenafil and tadalafil. Combined with nitrates such as nitroglycerin, they can lower blood pressure to dangerous levels. People with diabetes, high blood pressure, high cholesterol or heart disease often take nitrates².
• Sibutramine. This diet drug left the U.S. market in 2010 over cardiovascular risks, and in some people it sharply raises blood pressure and heart rate¹.
• Anabolic steroids. The California team lists links to liver injury, kidney damage, heart attack and stroke¹.

If you take nitrates or other heart medicines, a hidden drug can turn a casual purchase into a serious risk. That’s reason enough to ask a pharmacist before trying any product sold for sex, weight loss or muscle.

Warnings and recalls haven’t kept tainted products off the market

You might assume an FDA warning ends the story. The record says otherwise.

In the California analysis, fewer than half of the 776 products (46.4%) were tied to a voluntary recall¹. Most of the rest got only a public notice. The FDA sent warning letters over just 7 of them¹.

Some products simply came back. Twenty-eight were flagged again at least six months after an earlier warning, and 19 of those carried a new drug the next time¹.

In October 2018, the FDA told a trade publication that sellers often relabel products to dodge detection⁸. It also said then that it lacked authority to order a mandatory recall of drugs⁸. In a commentary, Pieter Cohen, a physician at Cambridge Health Alliance and Harvard Medical School, noted that the FDA has had power to order mandatory recalls of supplements since 2011, yet reported using it for none of the brands in the study¹⁰.

The FDA’s 2018 explanation points to a gap. A spiked product generally isn’t a legal supplement, yet the agency said it couldn’t force a drug recall either⁸. We could not confirm whether that position has changed since.

What happens after a recall? In a study published in 2014, Cohen and colleagues checked³.

They bought 27 supplements that had been recalled for drug spiking, on average almost three years after the recall³. Eighteen, two out of three, still contained a banned drug. Six held extra banned ingredients the FDA hadn’t reported³.

The study was partly funded by Consumers Union, and the testing lab was co-owned by one of the authors³. Cohen has also disclosed research support from Consumers Union and a research collaboration with NSF International, which certifies supplements¹⁰.

A 2022 study by Cohen’s team looked at 31 products that had drawn FDA warning letters over three stimulants¹¹. Only one was recalled. Nine were still for sale online about six years later, and five of those nine held a prohibited ingredient¹¹. The sample was small, but the pattern matched.

The lesson: a recall notice is a warning to you, not proof the product is gone.

Cheaper plants often stand in for costly ones

Hidden drugs make headlines. Swapped herbs are quieter, and for some popular herbs they are strikingly common.

In 2024, staff of the American Botanical Council published a review in Natural Product Reports⁴.

The council is a nonprofit. The review was funded by the Botanical Adulterants Prevention Program, a partnership of the council, the American Herbal Pharmacopoeia and a University of Mississippi research center. The program’s backers include companies in the herb, medicinal plant and supplement industries, along with nonprofit groups⁴.

The team pooled 78 publications covering 2,995 samples of five popular herbs. In all, 818 were adulterated or mislabeled⁴.

Herb	Samples tested	Share adulterated or mislabeled
Ginkgo leaf	533	About 57%
Black cohosh	320	42%
Echinacea	200	28.5%
Elder berry	695	17%
Turmeric	1,247	16.5%

Source: Orhan, Gafner and Blumenthal, 2024⁴.

The tricks fit each herb’s test. Ginkgo extract is often spiked with pure plant compounds such as rutin and quercetin, or with extract of Japanese sophora flowers or fruit⁴. Black cohosh gets swapped for related Asian species.

Elder berry extract may be stretched with black rice extract, purple carrot or synthetic dyes, which can fool a simple color-based test⁴. Undeclared colorants have also turned up in bilberry and St. John’s wort⁴.

Pricey ingredients invite the same game. In the 2024 military-discount study, one product listed saffron but held safflower flower instead⁹.

Two patterns stand out. Licensed or registered herbal medicines in the review, such as 30 ginkgo products, all proved authentic, while 73% of ginkgo dietary supplements were adulterated⁴. And across all five herbs, extracts were adulterated about half the time, compared with about 20% of powders⁴.

These numbers need care. Studies used different methods, and some products were counted more than once. For elder berry, samples tested by manufacturers ran far higher than those tested by contract labs, which the authors blame on selection bias⁴. The authors say the rates apply only to these five herbs⁴.

Most swaps cheat your wallet rather than your health. The authors say none of the reported ginkgo adulterants are considered harmful⁴.

The exceptions are why identity matters. The FDA says yellow oleander, found in place of tejocote, can harm the heart and blood vessels, nerves and gut, sometimes severely or fatally¹⁴. Our companion article on botanical identification explains how companies are supposed to catch swaps like that. Our ginseng article covers that herb’s adulteration review.

Kratom shows how a plant product can be spiked

Kratom is a plant whose leaf contains only trace amounts of a compound called 7-hydroxymitragynine, or 7-OH¹³. But concentrated 7-OH products, such as gummies and drink shots, are sold online and in gas stations, corner stores and vape shops¹².

In July 2025, the FDA recommended controlling certain 7-OH products under federal drug law, saying 7-OH binds to the body’s opioid receptors¹². The agency said it was not targeting natural kratom leaf¹².

On July 1, 2026, HHS announced that the Drug Enforcement Administration had filed notices of intent to temporarily place 7-OH above a set threshold, plus three related compounds, in Schedule I¹³. Those notices start the process; no temporary scheduling order had been issued as of that announcement¹³. We could not confirm whether one has been issued since, so check the DEA’s current status.

Mislabeling is part of the problem. The FDA warns that 7-OH products may misstate how much they contain¹². In February 2026, chewable tablets were recalled for holding more 7-OH than their labels claimed⁶.

Another product, sold as a supplement, was recalled in May 2026 for undeclared kratom compounds, including mitragynine pseudoindoxyl⁶. HHS says that compound is a chemical rearrangement product of 7-OH that doesn’t occur naturally in the plant¹³.

Ten red flags for a high-risk product

Natural health rests on knowing what goes into your body. Checking for adulteration is that value in action. Even the industry agrees: in 2018 the Council for Responsible Nutrition, a supplement trade group, said spiked products “are not dietary supplements”⁸.

Before you buy, count the flags. One flag calls for caution. Two or more means you should look harder or walk away. This list is our own, built from the sources cited.

1. It’s sold for sex, weight loss, muscle, pain, sleep or energy. These are the categories the FDA flags¹⁵.
2. It promises fast, drug-like results. The FDA lists claims that sound too good to be true as a warning sign⁵.
3. “Herbal” or “all natural” is the main pitch for a strong effect. Those words don’t guarantee safety⁵.
4. It’s a candy, honey or syrup sold for sexual performance. These formats fill FDA’s recent notices and recalls²⁶.
5. You found it at a gas station, convenience store, salon or in a social media ad⁵.
6. It arrives by international mail from a seller you can’t vet. Mail screening caught about a third of flagged products in 2014–2016¹.
7. The label boasts an “FDA-approved facility.” The FDA does not approve facilities⁵.
8. It has a wall of glowing reviews about how well it works⁵.
9. The price seems low for an herb known to be pricey. That’s a reason to ask how the seller confirmed the plant. This flag is our suggestion, based on the profit motive behind swaps⁴⁹.
10. The brand or product name has appeared in an FDA warning before. Some tainted products return under the same or a new name¹⁸.

What the record shows, rated

Belief	Evidence rating	What the research shows
Products sold for sex, weight loss or muscle sometimes hide prescription drugs	Strong evidence	Hundreds of FDA-flagged products, with recalls continuing in 202616
“All natural” on the label rules out hidden drugs	Evidence says no, or unsafe	The FDA warns those words guarantee nothing5
A recall takes a tainted product off the market	Evidence says no, or unsafe	Two of three recalled products bought years later still held banned drugs311
Some popular herbs are often swapped or spiked	Strong evidence	Repeated testing of ginkgo and black cohosh, with rates varying by study4
Most herb swaps are poisonous	Evidence says no, or unsafe	Most cheat buyers rather than harm them, but some swaps are toxic414
A third-party seal rules out adulteration	Not enough evidence	We found no study comparing certified and uncertified products; none of 30 tested weight-loss products carried a seal9

If you think a product was tainted

Stop taking it and keep the bottle. Tell your clinician or pharmacist what you took, especially if you use nitrates or other heart medicines².

Call 911 if someone collapses, has a seizure, has trouble breathing or can’t be woken up¹⁵. For other worries about a possible poisoning, call Poison Control at 1-800-222-1222¹⁵.

Then report it. You can send the FDA a report on a side effect through MedWatch². You can also report a suspicious product so the FDA can test it for hidden ingredients⁵.

Questions readers ask

The bottom line

Adulteration has two faces. One is a prescription drug hidden in a product that calls itself natural, mostly in pills, candies and honeys sold for sex, weight loss or muscle. The other is a cheaper plant, dye or chemical slipped in place of an herb you paid for. Neither problem is caught before sale, and recalls haven’t reliably cleared spiked products from the market.

You can lower your risk without giving up herbs. Be most careful in the high-risk categories, count the red flags, search FDA’s lists while knowing their limits, and ask sellers how they confirm what’s in the bottle. If something feels wrong after taking a product, stop, keep the bottle and report it.

Keep exploring: botanical identity testing.

Related reading

• What gets into supplements that isn’t on the label
• Third-party tested says what’s in the bottle, not that it works
• A supplement brand can outsource the making, not the responsibility
• American ginseng eased cancer fatigue, but a review found a quarter of products adulterated
• Before an herb becomes a capsule, someone must prove it’s the right plant

Sources

1. Tucker J, Fischer T, Upjohn L, Mazzera D, Kumar M. “Unapproved Pharmaceutical Ingredients Included in Dietary Supplements Associated With US Food and Drug Administration Warnings.” JAMA Network Open, 2018;1(6):e183337. pubmed.ncbi.nlm.nih.gov
2. U.S. Food and Drug Administration. “Tainted Honey-based Products with Hidden Active Drug Ingredients.” FDA, content current as of April 22, 2026. fda.gov
3. Cohen PA, Maller G, DeSouza R, Neal-Kababick J. “Presence of Banned Drugs in Dietary Supplements Following FDA Recalls.” JAMA, 2014;312(16):1691–1693. pubmed.ncbi.nlm.nih.gov
4. Orhan N, Gafner S, Blumenthal M. “Estimating the Extent of Adulteration of the Popular Herbs Black Cohosh, Echinacea, Elder Berry, Ginkgo, and Turmeric: Its Challenges and Limitations.” Natural Product Reports, 2024 (funded by the ABC-AHP-NCNPR Botanical Adulterants Prevention Program, which is supported by industry members). umb.herbalgram.org
5. U.S. Food and Drug Administration. “Avoiding Products Contaminated with Hidden Ingredients.” FDA, content current as of June 10, 2025. fda.gov
6. U.S. Food and Drug Administration. “Recalls – Health Fraud” (2026 list). FDA, content current as of October 8, 2026. fda.gov
7. U.S. Food and Drug Administration. “Questions and Answers on Dietary Supplements.” FDA, content current as of August 27, 2026. fda.gov
8. Long J. “Researchers Find Nearly 800 ‘Supplements’ in FDA Database Identified as Tainted With Drug Ingredients.” SupplySide Supplement Journal, via New Hope Network, October 15, 2018. newhope.com
9. Crawford C, Avula B, Lindsey AT, Katragunta K, Khan IA, Deuster PA. “Label Accuracy of Weight Loss Dietary Supplements Marketed Online With Military Discounts.” JAMA Network Open, 2024;7(5):e249131. pubmed.ncbi.nlm.nih.gov
10. Cohen PA. “The FDA and Adulterated Supplements—Dereliction of Duty.” JAMA Network Open, 2018;1(6) (invited commentary). pubmed.ncbi.nlm.nih.gov
11. Cohen PA, Avula B, Katragunta K, Khan I. “Recalls, Availability, and Content of Dietary Supplements Following FDA Warning Letters.” JAMA, 2022;328(4):393–395. pubmed.ncbi.nlm.nih.gov
12. U.S. Department of Health and Human Services. “FDA Takes Steps to Restrict 7-OH Opioid Products Threatening American Consumers.” HHS press release, July 29, 2025. hhs.gov
13. U.S. Department of Health and Human Services. “HHS, FDA Commend DEA Action Against Dangerous Enhanced 7-OH Products.” HHS press release, July 1, 2026. hhs.gov
14. U.S. Food and Drug Administration. “FDA Issues Warning About Certain Products Containing Toxic Yellow Oleander.” FDA safety alert, content current as of September 22, 2026. fda.gov
15. America’s Poison Centers. “Poison Help” (1-800-222-1222). Accessed October 2026. poisonhelp.org