What FDA's ZUBB warning says about hidden ingredients in weight-loss supplements

What did FDA announce about ZUBB Dietary Supplement?

On September 4, 2026, the Food and Drug Administration issued a public notification advising consumers not to purchase or use ZUBB Dietary Supplement.

The product was promoted and sold for weight loss on various websites and possibly in some retail stores. It was identified during an examination of international mail shipments.

FDA laboratory analysis confirmed that ZUBB Dietary Supplement contains sildenafil, an ingredient not listed on the product label. Sildenafil is the active ingredient in the FDA-approved prescription drug Viagra, used to treat erectile dysfunction.

What is the risk from the hidden ingredient?

According to the FDA notice, sildenafil may interact with nitrates found in some prescription drugs such as nitroglycerin and may lower blood pressure to dangerous levels.

The agency states this is especially concerning for people with diabetes, high blood pressure, high cholesterol, or heart disease who commonly take nitrate-containing medications.

Who should report adverse events?

The notice says health care professionals and consumers should report adverse events or side effects related to the use of this product to the FDA's MedWatch Safety Information and Adverse Event Reporting Program.

Reports can be completed and submitted online through the MedWatch Online Voluntary Reporting Form, or downloaded and faxed to 1-800-FDA-0178.

What a supplement brand should take from this notice

This notification concerns one specific product — ZUBB Dietary Supplement — that FDA found to contain a hidden drug ingredient. The warning does not discuss any other brands or products.

FDA's announcement is an example of the agency's ongoing public notices about products that are typically promoted for sexual enhancement, weight loss, pain relief, and body building and are often represented as being all natural.

The agency states it is unable to test and identify all products marketed as dietary supplements that have potentially harmful hidden ingredients. Consumers are advised to exercise caution before purchasing these types of products.

For a brand owner selling weight-loss supplements, one practical step is to ensure your manufacturer provides robust identity testing on every incoming ingredient lot — something that is already required under 21 CFR Part 111 for finished-product manufacturers. This does not guarantee a product is free of undeclared ingredients, but it helps confirm what is going into the formula.

We suggest reviewing your supplier qualification records and asking your contract manufacturer whether they screen raw materials with methods capable of detecting common pharmaceutical adulterants. This is especially relevant if your product belongs to a category that FDA has flagged as frequently targeted for adulteration, including weight-loss and sexual-enhancement products.

What the announcement does NOT say

The FDA notice does not mention any brand other than ZUBB Dietary Supplement. It does not implicate the contract manufacturer, the distributor, or any retailer by name. It does not discuss how the product was sourced beyond stating it was identified during an examination of international mail shipments.

The notice does not state how much sildenafil was found or whether the amount was consistent with a therapeutic dose. It does not describe the testing methodology FDA used beyond calling it laboratory analysis.

The notice does not mention whether FDA intends to pursue enforcement action such as a seizure, injunction, or criminal charges, which the agency is authorized to do for products containing undeclared active pharmaceutical ingredients. It is a consumer advisory only.

Frequently asked questions

What did FDA find in ZUBB Dietary Supplement?

FDA laboratory analysis confirmed the product contains sildenafil, the active ingredient in the prescription drug Viagra. Sildenafil was not declared on the product label.

How was this product discovered?

According to the FDA notice, it was identified during an examination of international mail shipments. The agency has not released additional details about the shipment's origin or how the product was flagged for testing.

Is my weight-loss supplement affected by this notice?

The FDA notice is specific to one product: ZUBB Dietary Supplement. The announcement does not reference any other brands. We cannot tell you whether your product contains undeclared ingredients; testing through a qualified laboratory is the way to verify your label's accuracy.

Why do weight-loss supplements keep showing up in FDA fraud notices?

The notice states that products containing hidden drug ingredients are typically promoted for sexual enhancement, weight loss, pain relief, and body building, and are often represented as being all natural. These categories have a history of adulteration, but the notice does not quantify frequency.

What should a brand do if it learns its product contains a hidden ingredient?

The notice did not issue directives to firms. As a general point of responsible conduct, a brand that identifies an undeclared pharmaceutical ingredient in its product should consult qualified regulatory counsel, consider a voluntary recall if the product is on the market, and report adverse events through the MedWatch program.