Why Do Medicine Bottles Contain Cotton? Should You Remove it?

Ever wonder why there used to be a cotton ball in medicine bottles? While this practice has become much less common, many people may not know the main reason it was used in the past and why it is no longer included today. 

Key Takeaways

• Cotton balls were originally added to medicine bottles to cushion fragile tablets and prevent them from breaking during shipping.

• Contrary to popular belief, cotton was not primarily used for moisture control; in fact, it can absorb and retain moisture from the surrounding air.

• Improvements in tablet manufacturing and packaging have gradually made cotton inserts redundant in most medicine bottles.

• Today, medications are protected using specialized packaging solutions such as desiccants, oxygen absorbers, and blister packs, which help prevent moisture, oxidation, and physical damage.

Why Was Cotton Placed in Medicine Bottles?

Many people might think cotton balls were placed in the bottles to absorb moisture and keep the tablets dry, but the main reason is much more nuanced. 

Initially, Bayer started the practice of using cotton balls in its aspirin bottles in the early 1900s. At the time, packaging technology was limited and tablets lacked the protective coatings that are common today. Hence, the tablets were more fragile and could not be packed firmly enough to withstand shipping without chipping or breaking. Customers who received such chipped or broken pills risked taking an inaccurate dose if they tried to re-assemble the fragments. To prevent the tablets from moving around and breaking, cotton balls were used to fill the empty space inside the bottle. This ensured tighter packaging and helped absorb the impact if the bottle was dropped. 

Why Don’t They Put Cotton in Pill bottles Anymore?

Over the following decades, tablet manufacturing improved considerably.Over time, improvements in tablet manufacturing, protective coatings and pharmaceutical packaging made tablets more resistant to breakage and reduced the need for loose cushioning inside bottles. 

Though the advancements in technology lowered the possibility of tablets being damaged in transit, manufacturers continued to include cotton coils  in pill bottles for many years to satisfy the expectations of the customers. The practice was reduced almost after two decades of introducing enteric-coated tablets.

Do They Still Put Cotton in Medicine bottles?

Although coated tablets may not require the extra cushioning, plain, uncoated tablets, some capsules and soft gels can still chip, break or stick together if allowed to move freely inside the bottle. In such cases, cotton or any alternative packing materials like silica beads may be necessary. For this reason, some pharmaceutical companies continue to use cotton, cotton coir or cushioning materials in their bottles. Consumer habits and perceptions may also be a contributing factor for continuing this practice. Some people associate the presence of cotton with integrity of the product and may view it as a sign that the contents have not been tampered with.

Does Cotton Keep Medicine From Getting Damp?

Cotton is hygroscopic (a substance that can easily absorb water or moisture from the surrounding air). This may be the reason people assumed that cotton balls were placed in pill bottles to control moisture and keep the tablets dry. 

Cotton can absorb moisture, and pharmaceutical packaging manufacturers describe cotton coils as providing some protection against humidity and condensation. However, its historical role in pill bottles was chiefly physical cushioning. Cotton is not a substitute for purpose-designed desiccants for moisture control.

According to MedlinePlus, the U.S. National Library of Medicine's consumer resource, if your medicine bottle contains a cotton insert, remove it after opening unless the manufacturer's instructions specifically say otherwise. MedlinePlus advises removing cotton because it can pull moisture into the bottle. 

Today, moisture control can be achieved by silica gel packets or canisters. These desiccants are designed to absorb excess moisture. They also help maintain the stability of the medication. In many cases, they may be intended to remain in the bottle until all of the contents have been used. 

Consumers should always follow the manufacturer's specific instructions regarding storage of medications.

What Do Manufacturers Use Instead of Cotton Today?

Modern pharmaceutical packaging has replaced cotton through more targeted and effective technologies. 

• Silica gel or clay desiccant packets: To control moisture and keep medications dry. 

• Oxygen absorbers: To help prevent oxidation, which can degrade certain medicines over time.

• Blister packs: To reduce physical contact between tablets, providing better protection against damage, moisture, and tampering.

Should You Throw Away the Cotton in a Medicine Bottle?

According to MedlinePlus, consumers are advised to remove the cotton from medication bottles after opening them, as the material can attract and retain moisture over time.

Desiccant canisters are different from cotton balls and are typically intended to stay in the bottle until all the medication has been used. Silica gel is generally considered non-toxic, but swallowing a packet can pose a choking hazard and, in rare instances, may cause an intestinal blockage. For this reason, desiccant packets always carry a "Do Not Eat" warning and should be kept out of reach from small children.

One interesting detail is that the "cotton" found in pill bottles is not always made of cotton. Interestingly, pharmaceutical bottle inserts are not always made from conventional cotton. Some products use other fibers, such as rayon, depending on the packaging application. Pharmaceutical packaging manufacturers list both cotton and rayon as materials used for these inserts. 

Conclusion

The cotton ball found in medicine bottles was initially a practical solution designed to protect tablets from damage during shipping. Many people may associate it with moisture control but its primary purpose was to keep tablets firmly packed and for cushioning. 

As pharmaceutical manufacturing and packaging technologies have advanced, cotton became largely unnecessary and was replaced by more effective solutions such as desiccants, oxygen absorbers, and blister packs. 

Although some companies still use cotton or similar materials for specific products, modern packaging provides better protection, making the once-common cotton insert a largely historical feature of pill bottles.

References

1. National Library of Medicine. "Storing Your Medicines." MedlinePlus. Accessed September 1, 2026. https://medlineplus.gov/ency/patientinstructions/000534.htm.