Bismuth, the ancient element, is the pink hue found in today's Pepto-Bismol formula.

Key Insights

What do your stomach remedy, your eyeshadow, and your home's sprinkler system all share? They all involve a shimmering metal known as bismuth.

You may have spotted them in science museum gift shops: bismuth crystals — often formed into tiny pyramids, as though crafted in some distant alien lab. But the ability of bismuth to create shiny, rainbow-hued, stair-step crystals as it cools is just one of its fascinating traits. This metal is also less dense as a solid than as a liquid, it is a poor conductor of heat and electricity, and unlike most heavy metals, it's non-toxic.

Ranked 83rd on the periodic table of elements, bismuth is a brittle, silvery metal that can be found both naturally in the earth and as part of various ore compounds that include tin, copper, lead, silver, and gold. Interestingly, we don't often mine bismuth for its own sake — it's usually a byproduct of extracting these more valuable metals. Bismuth is roughly twice as abundant in the Earth's crust as gold.

Although bismuth was likely used in ancient Mesoamerica and Egypt, it was discovered in Europe around 1400 BCE by an unknown alchemist — likely one of those trying to turn lead into gold. Western alchemists contributed greatly to the development of chemistry, and even though they didn't fully understand this pale, heavy, opalescent metal with a low melting point, they started using it for decoration. It wasn’t until 1753 that a French chemist, Claude-François Geoffroy, identified bismuth as a distinct element from lead.

How Do We Use Bismuth?

Bismuth is abundant, which makes it useful for various applications. One significant advantage is that it's non-toxic and not a carcinogen, so it can be safely incorporated into products such as paints and cosmetics. For example, bismuth oxide, which turns yellow when oxidized, serves as a yellow pigment in makeup and paints. Additionally, bismuth (III) chloride oxide is used to give cosmetics a pearlescent finish.

Due to its low melting point, bismuth is commonly used in sprinkler systems: When the heat from a fire raises the temperature of the bismuth plug in the sprinkler to its melting point (520.52°F or 271.40°C), the metal melts, releasing water onto the flames. Sprinkler systems represent around a third of bismuth's industrial use, but it's also found in plumbing, shotgun pellets, fishing tackle, soldering, and other products that once relied on toxic lead.

Bismuth's Notable Role: Pepto-Bismol

One of the most unexpected uses for bismuth is in the popular over-the-counter digestive remedy, Pepto-Bismol. Yes, that minty pink liquid that helps with heartburn contains over a quarter of a gram of bismuth per dose. Pepto-Bismol has been around for 80 years, and what sets it apart from other antacids is that one of its main active ingredients is bismuth subsalicylate (BSS).

Most antacids use a base like baking soda, magnesium hydroxide, aluminum hydroxide, or calcium carbonate to neutralize stomach acids. Though their methods vary slightly, the base works by immediately interacting with the acids, converting some into gas, which is then released as a burp. Some antacids contain only a base — like Tums, which uses calcium carbonate — while others, such as Alka-Seltzer, combine a base with a pain reliever like aspirin. Pepto-Bismol uses calcium carbonate as the base, but its pain reliever is BSS, making it a distinctive choice — one of only a few medications that include it.

Bismuth salts have been used for pain relief since the 1700s. Though aspirin has largely overshadowed them in popularity, the enduring success of Pepto-Bismol proves they work. BSS, which is chemically similar to aspirin, is broken down in the body into salicylic acid, a compound known for its anti-inflammatory and pain-relieving properties. BSS also has other effects that are not fully understood, but appear to support the gastrointestinal system, making it effective for treating both diarrhea and indigestion.

Pepto-Bismol contains a significant amount of bismuth — enough that if you have a few hours to spare, you can actually extract the metal from the pills. With even more time — say, a couple of days — you can use it to grow metallic bismuth crystals right at home. It's a delicate process that requires some basic chemistry tools, but it highlights how even seemingly otherworldly creations might come from an everyday kitchen lab.