The short answer

Cotton was put in pill bottles originally to prevent breakage of pills during shipment. But through pill coating innovation, the cotton protection is mostly not needed anymore. Still, some pharmaceutical companies choose to keep the cotton in pill bottles because consumers expect it to be there.

The long answer

When you open a new bottle of aspirin, you are occasionally confronted with a white ball of puff. But why do they put cotton in pill bottles?

Cotton balls (or rayon or polyester balls) have blocking our path to pills since sometime around 1914 or 1915. Around this time, pharmaceutical company Bayer was the first to introduce cotton balls in their aspirin bottles in order to prevent breakage during shipment. The worry was that if customers opened a bottle with some fragmented pills, they might end up taking the wrong dosage. So they put cotton in pill bottles to keep the pills intact.

Then in the 1980s innovation struck: pill coatings. Bayer introduced Toleraid® Micro-Coating in 1984 to make the aspirin easier to swallow and protect it from breaking, rendering the cotton in pill bottles mostly unnecessary. Protective pill coatings generally became more common in the pharmaceutical industry during this time period.

Gradually cotton balls were removed from certain pill bottles since they were redundant with these protective pill coatings. By 1999, Bayer had stopped putting in cotton in most of their pill bottles. Other companies also started removing cotton around this time as a cost-cutting measure, with one company reporting that they saved $150,000 year on cotton with this move.

So if cotton doesn't really serve a purpose any more, why do we still see it in some pill bottles?

Why is there cotton in pill bottles?

Reason #1: Consumers prefer to have the cotton ball.

After decades of cotton balls, some consumers are shocked when they open a pill bottle and don't see fluff. Some people believe that cotton keeps pills fresher or is an indicator that the medicine hasn't been tampered with. (Both of these beliefs are incorrect.) Others are simply nostalgic for the times of cotton balls in pill bottles, with one woman remarking, "I like them. They remind me of my childhood. It's very familiar."

Since cotton balls in pill bottles are commonplace and consumers don't realize they're mostly useless, some pharmaceutical companies choose to keep the fluff in their bottles.

Reason #2: Not all pills have protective coating.

Cotton's original purpose was to prevent pills from breaking during shipment. Since the advance of pill coatings, many medications don't need this protection. But not all pills have protective coating. Chewable pills and pills with an enteric coating (one that allows the pill to bypass the acidic stomach so it can dissolve in the intestine) often will have cotton for protection.

For example, on Bayer's own website they state that, "We place cotton in some bottles of Bayer® Aspirin to help minimize breakage of the product during shipment from the manufacturing plants to the store shelf. This is especially important for the enteric-coated tablets, as any chip in the coating can affect the tablets ability to bypass the stomach undissolved." This explains why some pill bottles have cotton while others do not.

Should you remove cotton from pill bottles?

Yes, you should remove the cotton from pill bottles. The U.S. ​National Institutes of Health​ recommends that consumers remove the cotton once they've opened the bottle. The reason has to do with cotton's hygroscopic nature, or its ability to easily absorb water from its surroundings. Once opened, the cotton can actually draw moisture into the bottle which can cause degradation of the medication. So, don’t keep the cotton in the pill bottle if you want to keep your medicine in good shape.

🧠 Bonus brain points

When did tamper-resistant packaging begin?

In the United States, tamper-resistant packaging (e.g. foil-sealed caps, plastic wrapping, boxes glued shut) of over-the-counter (OTC) medication began in 1982 as a response to the tragic "​Tylenol murders​." In the Chicago area, some boxes of Tylenol had been laced with a lethal dose of cyanide, leading to the deaths of seven people in the span of three days.

Johnson & Johnson, the makers of Tylenol, worked swiftly with the FDA to introduce packaging elements that would make it obvious to the consumer if it had been tampered with. By 1989, there were federal guidelines to make tamper-resistant packaging mandatory for OTC medications.

Check out some other curious questions:

Sources

Bayer. (n.d.). Frequently Asked Questions. Aspirin USA. https://www.bayeraspirin.com/faqs/

CapPlus Technologies. (2021, August 30). The Benefits of Cotton in Pill Bottles. CapPlus Technologies. https://capplustech.com/2021/08/30/cotton-in-pill-bottle/

Harris, G. (1999, September 10). Bayer Decided They Don’t Need Cotton Anymore, Despite Ritual. The Wall Street Journal. https://www.wsj.com/articles/SB936916262727338623

Jones, M. (2021, July 19). Why Is There a Cotton Ball in Pill Bottles?. Reader’s Digest. https://www.rd.com/article/cotton-ball-in-pill-bottles/

Markel, H. (2014, September 29). How the Tylenol murders of 1982 changed the way we consume medication. PBS News Hour. https://www.pbs.org/newshour/health/tylenol-murders-1982

Taylor, A. (2021, September 1). The Real Reason There Are Cotton Balls In Pill Bottles. Health Digest. https://www.healthdigest.com/593299/the-real-reason-there-are-cotton-balls-in-pill-bottles/

Times Publishing Company. (1999, September 11). Cotton pulled from Bayer aspirin. Tampa Bay Times. https://www.tampabay.com/archive/1999/09/11/cotton-pulled-from-bayer-aspirin/

Tsoucalas, G., Karamanou, M., & Androutsos, G. (2011, January 1). Travelling through Time with Aspirin, a Healing Companion. Sage Journals. https://journals.sagepub.com/doi/10.1177/1721727X1100900102

Vorvick, L. J. (Ed.). (2022, January 29). Storing your medicines. MedlinePlus. https://medlineplus.gov/ency/patientinstructions/000534.htm