Buying Supplements Online: Marketplaces, Counterfeits and Third-Party Sellers
What small studies and FDA say about supplements bought online: labels that do not match, counterfeits and hidden drugs, and how to check a product without relying on reviews.
Content last updated . This page has not been medically reviewed.
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Words used in this page
- Counterfeit or falsified: a product that pretends to be something it is not. The studies we read use terms such as "falsified" and "substandard" for products that do not match what they claim. [2]
- Adulterated or misbranded: terms the US Food and Drug Administration (FDA) uses for products that contain something they should not or are labeled wrongly. FDA describes some websites as offering "potentially counterfeit, controlled, adulterated or misbranded products". [3]
- Third-party seller: a business that sells through a website it does not own. The sources we read do not describe how any online marketplace checks its sellers, so we cannot say how that works.
What the sources found
The table separates what each source actually tested. These are small studies of particular products at particular times. They do not tell us how common the problem is across all online products.| Question | What the source found | Strength of evidence |
|---|---|---|
| Do online supplements match their labels? | In one 2022 case series, 30 immune-health supplements were bought from an online marketplace and analyzed. Thirteen of the 30 had accurate labels. No product carried a third-party certification seal. [4] | Small case series; one product category; one month of purchases |
| Can an "herbal" product contain a prescription drug? | In a 3-product study of "herbal" sexual-performance supplements bought from an e-commerce platform, all three contained sildenafil citrate, a prescription drug ingredient. One was judged falsified and failed quality tests. [2] | Very small; preliminary |
| Are illegal sports products sold online? | Researchers in Slovakia analyzed 16 unregistered sports supplements bought anonymously online that claimed to contain selective androgen receptor modulators (SARMs). The claimed ingredient was confirmed in 9 samples and not reliably found in 7. [5] | Small; one country |
| Does FDA test supplements before sale? | FDA states it "does not test dietary supplements before they are sold to consumers." [6] | Official statement |
| Are online reviews reliable? | FDA says reviews on popular online marketplaces and social media "can be fake". [7] | Official consumer warning |
Proper evidence not found: we searched PubMed (counterfeit and online dietary supplement terms), FDA and NCCIH pages for a study comparing how often counterfeits appear on different marketplaces or against shop-bought products. We found only the small case series above, so we cannot say whether online products are more or less risky than shop products.
Why hidden ingredients matter
FDA says it has found numerous products promoted as "all-natural" that contain hidden and dangerously high amounts of prescription drug ingredients. [7] Products for weight loss, sexual enhancement and bodybuilding are the groups NCCIH names as possibly containing prescription drugs or unlisted ingredients. [1] See Hidden Drugs in Supplements for the documented examples.FDA also warns about products ordered direct from overseas sources by mail, which can bypass normal Customs and FDA inspections, and says fraudulent products may be made in unregistered facilities under unknown or unclean conditions. [7]
How to check a product (not where to buy)
- Read the whole label. The label guide explains the Supplement Facts panel and the manufacturer name and address that US labels must carry. [6]
- Be wary of cure claims. FDA lists "one product does it all", personal testimonials, quick fixes, "all natural" cures and "miracle cure" wording as tip-offs to health fraud. [7]
- Look for independent testing, with limits. A certification seal shows less than people assume; see what third-party seals show.
- Ask a pharmacist or clinician first. FDA advises talking with a doctor, pharmacist or other health professional before deciding to purchase or use a supplement. [8] Pharmacists can also help with medicine interactions.
- Keep the package and lot number if something goes wrong, so a report can describe the exact product.
If something looks wrong
FDA says anyone may report a suspected supplement reaction through its Safety Reporting Portal, and product problems can be reported there too. [6] FDA also points readers to its page for reporting unlawful sales of medical products on the internet, and to the Federal Trade Commission for problem advertising. [7][9] Steps are in How to Report a Side Effect in the US. Do not change or stop a prescribed medicine on your own; ask the prescriber or pharmacist.Frequently asked questions
Are supplements sold online more likely to be fake?
Proper evidence not found. The small studies we read looked only at products bought online and found label mismatches, hidden drug ingredients and falsified products in some of them. [4][2] None compared online with shop purchases.
Does a good star rating mean a product is safe?
No. FDA says reviews on popular online marketplaces and social media can be fake. [7]
What is the difference between a counterfeit and a poorly made supplement?
A counterfeit or falsified product pretends to be something it is not; a poorly made one may simply not match its label. The studies we read used terms such as falsified and substandard for products that failed to match their claims. [2] Either can be harmful, and either can be reported.
Can FDA tell me whether a specific product is safe?
FDA says it does not approve dietary supplements for safety and effectiveness before they are marketed, and it does not test them before sale. [8][6] Ask a pharmacist, check FDA's alerts, and see Recalls and Safety Alerts.
Who should be most careful?
FDA and NCCIH single out weight-loss, sexual-enhancement and bodybuilding products. [1] People on medicines, who are pregnant or breastfeeding, or who are buying for children should ask a clinician or pharmacist first.
References
- National Center for Complementary and Integrative Health (NIH). Using Dietary Supplements Wisely. Read 2026-10-22.
- Ho HMK, et al. The era of fake medicines: Investigating counterfeit medicinal products for erectile dysfunction disguised as herbal supplements. International Journal of Pharmaceutics. 2022;617:121592. Read 2026-10-22 (abstract).
- U.S. Food and Drug Administration. Health Fraud Scams (content current as of 2026-07-22). Read 2026-10-22.
- Crawford C, et al. Analysis of Select Dietary Supplement Products Marketed to Support or Boost the Immune System. JAMA Network Open. 2022;5(8):e2226040. Read 2026-10-22 (abstract).
- Jendrzejewska I, et al. Rapid detection of illegal selective androgen receptor modulators in unregistered supplements. ADMET & DMPK. 2025;13(3):2685. Read 2026-10-22 (abstract).
- U.S. Food and Drug Administration. Questions and Answers on Dietary Supplements. Read 2026-10-22.
- U.S. Food and Drug Administration. 6 Tip-offs to Rip-offs: Don't Fall for Health Fraud Scams (content current as of 2021-03-04). Read 2026-10-22.
- U.S. Food and Drug Administration. Information for Consumers on Using Dietary Supplements (content current as of 2022-10-21). Read 2026-10-22.
- U.S. Food and Drug Administration. How to Report a Problem with Dietary Supplements (content current as of 2025-03-13). Read 2026-10-22.