The Complex History of Donnagel: Why Was Donnagel Discontinued?

October 6, 2025 •

4 min read

The U.S. Food and Drug Administration (FDA) has conducted a long-running review of over-the-counter (OTC) drugs since 1972, resulting in the removal of many products containing ingredients deemed ineffective or unsafe. This multi-decade regulatory effort is the key reason why was Donnagel discontinued, as multiple formulations were removed from the market due to changing standards and lack of evidence for their key ingredients.

Quick Summary

Donnagel was discontinued after the FDA banned several active ingredients due to lack of proven effectiveness or safety concerns. The brand had various formulations, including those with belladonna alkaloids and kaolin/pectin, all phased out by regulators.

Key Points

FDA Regulatory Action: The FDA systematically reviewed over-the-counter drugs, leading to the gradual removal of Donnagel's active ingredients for failing to prove effectiveness.
Ineffective Ingredients: Key Donnagel components like kaolin, pectin, and belladonna alkaloids were deemed insufficiently effective for OTC use, leading to their removal.
Controlled Substance Formulation: A Donnagel-PG version containing the opium-derived substance paregoric became a prescription-only medication, ending its OTC availability.
Shift to Proven Alternatives: Modern anti-diarrheals, such as loperamide (Imodium), have replaced older remedies by using more effective and scientifically validated mechanisms of action.
Multiple Reformulations: The Donnagel brand existed in several different formulations over its history, with each version eventually failing to meet evolving regulatory standards for safety and efficacy.
Adsorbent Theory Disproven: The older 'adsorbent' theory, where ingredients like kaolin and pectin were believed to bind to toxins, was largely discredited, paving the way for more targeted treatments.

The story of Donnagel is a prime example of how scientific understanding and regulatory standards can change the landscape of consumer medicine. For decades, multiple versions of Donnagel were a common household name for treating diarrhea. However, successive reviews by the FDA led to the removal of its key ingredients, ultimately causing the brand's complete discontinuation.

The FDA's OTC Drug Review and Donnagel

Starting in 1972, the FDA began a systematic review of all OTC drugs to ensure they were both safe and effective. This process, which spanned several decades, scrutinized the claims and ingredients of hundreds of thousands of products. Donnagel, a long-standing anti-diarrheal, was repeatedly caught in the crosshairs of this review as its formulations were based on older, less-proven ingredients.

The Belladonna Alkaloids Ban (1990)

One of the most significant blows to Donnagel was an FDA ban in 1990 on several ingredients found in some of its formulations. An L.A. Times article from that year reported that the FDA took action against the anti-diarrheal product Donnagel because manufacturers failed to provide proof that certain ingredients worked. The specific substances banned from OTC use included atropine sulfate, hyoscyamine sulfate, and scopolamine hydrobromide—a group known as belladonna alkaloids. These ingredients were believed to relax the smooth muscles of the gut to reduce cramping, but the FDA concluded there was insufficient evidence for this effect in OTC products.

The End of Kaolin and Pectin

Historically, Donnagel's earliest and most famous versions were based on kaolin and pectin, a combination also used in the classic Kaopectate. Kaolin is a type of clay, and pectin is a natural polysaccharide derived from fruit. Both were thought to work by 'adsorbing' (binding to) toxins, bacteria, and excess water in the gut, thereby solidifying stool. However, a later FDA review panel for OTC products concluded there was insufficient evidence to support the effectiveness of kaolin and pectin for diarrhea treatment. Following this determination, both ingredients were phased out of major commercial anti-diarrheal products in the U.S., including Donnagel and later versions of Kaopectate.

The Fate of Donnagel-PG

Another formulation, Donnagel-PG, contained an opium derivative known as paregoric. In the early 1990s, U.S. regulations changed, and anti-diarrheal drugs containing paregoric were reclassified, becoming prescription-only. This change effectively ended the over-the-counter availability of Donnagel-PG, removing yet another popular variant of the brand from pharmacy shelves.

Why Modern Anti-Diarrheals Are Different

The phasing out of Donnagel's ingredients coincided with the rise of modern alternatives with a scientifically proven mechanism of action. The new generation of anti-diarrheals does not rely on the outdated 'adsorbent' theory of clays but instead targets the root causes or physiological mechanisms of diarrhea more effectively. Key differences include:

Mechanism of Action: Modern drugs like loperamide (Imodium) work by slowing down intestinal motility, giving the body more time to absorb water and electrolytes. This is a more direct and proven approach than older adsorbent methods.
Proven Efficacy: Unlike the ingredients in Donnagel, modern anti-diarrheals have met the stringent effectiveness standards set by regulatory bodies like the FDA.
Safety Profile: While all medications carry risks, modern options have well-established safety profiles when used as directed, with better understanding of potential side effects and drug interactions.
Targeted Treatment: New prescription options, such as rifaximin for traveler's diarrhea or eluxadoline for IBS-D, address specific causes of diarrhea rather than using a general, less-effective approach.

Comparison: Donnagel Ingredients vs. Modern Alternatives


Feature	Donnagel (Older Formulations)	Modern Alternatives (e.g., Imodium, Pepto-Bismol)
Primary Active Ingredients	Kaolin, Pectin, Attapulgite, Belladonna Alkaloids	Loperamide HCl, Bismuth Subsalicylate
Mechanism of Action	Adsorption: Binds toxins and water, though efficacy was found to be unproven.	Motility Inhibition/Antisecretory: Slows intestinal muscle contractions (loperamide) or reduces inflammation and fluid secretion (bismuth).
FDA Regulatory Status	Removed from OTC market due to lack of proven effectiveness.	FDA-approved and widely available for OTC use.
Controlled Substance	Some formulations (Donnagel-PG) contained opium derivatives and became prescription-only.	Most OTC versions are not controlled substances.
Overall Efficacy	Found to have insufficient evidence of efficacy.	Clinically proven to be effective for symptomatic relief of diarrhea.

Alternatives to Donnagel

For those seeking alternatives to the long-discontinued Donnagel, several effective over-the-counter and prescription options are available. The best choice depends on the specific cause and severity of the diarrhea, but common and well-regarded options include:

Loperamide (Imodium): A highly effective OTC option that works by slowing intestinal movement to reduce the frequency and volume of loose stools.
Bismuth Subsalicylate (Pepto-Bismol, Kaopectate): Available over-the-counter, this medication works by balancing fluid movement in the digestive tract and may have antibacterial properties.
Oral Rehydration Solutions (Pedialyte): These are particularly important for replenishing lost fluids and electrolytes, especially in severe or prolonged cases of diarrhea.
Prescription Medications: For more persistent or severe cases, a doctor may prescribe an antibiotic for bacterial infections, or specific medications for conditions like Irritable Bowel Syndrome with Diarrhea (IBS-D).

Conclusion

In summary, Donnagel was discontinued not due to a single event, but rather a series of regulatory actions by the FDA over many decades. Its journey reflects the shift away from older, less-proven anti-diarrheal ingredients like kaolin, pectin, and belladonna alkaloids towards modern, evidence-based treatments. The cumulative effect of these regulatory changes, alongside the development of more effective medications with clearer mechanisms of action, led to the withdrawal of all Donnagel formulations. For consumers today, this evolution means access to safer and more effective anti-diarrheal options, such as loperamide and bismuth subsalicylate, that have met current standards of efficacy and safety.

Visit the FDA website for more information on the ongoing review of over-the-counter drug ingredients.

Frequently Asked Questions

Depending on the formulation, Donnagel contained different active ingredients over its history. Early versions included kaolin and pectin, while others used attapulgite or belladonna alkaloids (atropine, hyoscyamine, scopolamine).

In 1990, the FDA banned belladonna alkaloids from over-the-counter use in Donnagel because manufacturers could not provide sufficient evidence that these ingredients were effective for treating diarrhea in OTC formulations.

Yes, Donnagel-PG contained paregoric, an opium derivative. Due to changes in regulations, anti-diarrheal products with paregoric became prescription-only in the early 1990s, ending the OTC availability of Donnagel-PG.

The kaolin and pectin-based versions of Donnagel were removed from the market after an FDA advisory panel concluded there was 'insufficient evidence' to prove their effectiveness for treating diarrhea. A similar fate met Kaopectate, which also replaced its kaolin ingredient.

Effective modern alternatives include over-the-counter medications such as loperamide (Imodium) and bismuth subsalicylate (Pepto-Bismol). Oral rehydration solutions are also recommended to replenish lost fluids and electrolytes.

There wasn't a single date for the discontinuation of all Donnagel products, as different formulations were removed over time due to various FDA actions throughout the 1990s and early 2000s. Some product listings, such as an attapulgite-based Donnagel, show a discontinued National Drug Code (NDC).

The ingredients in older Donnagel formulations posed risks, which factored into their removal. Belladonna alkaloids could cause side effects like drowsiness and dry mouth, while adsorbent clays like attapulgite could slow the absorption of other medications.