Bismuth Subsalicylate

The need-to-know information for Bismuth Subsalicylate

Bismuth subsalicylate

Pearls and Fun Nuggets

1. It can make your tongue turn black ūüėú It causes a black tongue¬†and black¬†stools¬†in some users of the drug when it combines with trace amounts of¬†sulfur¬†in saliva and the colon to form¬†bismuth sulfide.[4]¬†Bismuth sulfide is a highly insoluble black salt, and the discoloration seen is temporary and harmless.

2. Salicylates are very toxic to cats ūüźą and thus bismuth subsalicylate should not be administered to cats.[11]

3. If you use it for too long, it can be toxic to humans too ūüė• Long-term use (greater than 6 weeks) may lead to accumulation and toxicity.[5]¬†Some of the risks of¬†salicylism¬†can apply to the use of bismuth subsalicylate.[6][7][8]

4. Bismuth Subsalicylate is a classic ūüé© Pepto-Bismol began being sold in 1900[17]¬†or 1901[18]¬†by a doctor in New York. It was originally sold as a remedy for infant diarrhea by¬†Norwich Pharmacal Company¬†under the name “Bismosal: Mixture Cholera Infantum”.[17]¬†It was renamed Pepto-Bismol in 1919.

5. Nobody really knows how exactly it works… ūüėÖBismuth subsalicylate is used as an antacid and antidiarrheal, and to treat some other gastrointestinal symptoms, such as nausea. The means by which this occurs is still not well documented though. It is thought to be some combination of the following:[13]

    • Stimulation of absorption of fluids and electrolytes by the intestinal wall (antisecretory action)
    • As a¬†salicylate, reducing inflammation/irritation of stomach and intestinal lining through inhibition of prostaglandin G/H synthase 1/2
    • Reduction in hypermotility of the stomach
    • Binding of toxins produced by¬†Escherichia coli
    • Bactericidal action of a number of its subcomponents, including salicylic acid[14]
    • Bactericidal action via a so-called¬†oligodynamic effect¬†in which small amounts of heavy metals such as bismuth damage many different bacteria species.
    • Weak antacid properties

Patient Perspectives

“Relieves my upset stomach, gas, diarrhea, heartburn, and its affordable.”


“Very effective for me with both nausea and diarrhea. Works well at preventing vomiting, in my experience.”


“I can’t take pepto bismol, because if I do I get an allergic reaction I will break out in a rash. Shame too, it does help but the rash isn’t worth the risk.”

Brandon Simpson, PA-C
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