Cough drops are lozenge-form, over-the-counter medications designed to temporarily relieve minor throat irritation and coughs. The Food and Drug Administration (FDA) mandates that all such products carry an expiration date. This date serves as the manufacturer’s guarantee of safety and full potency, determined through stability testing under controlled conditions. Because cough drops contain medicinal compounds, their quality and performance are subject to chemical change over time.
Safety Risks of Ingesting Expired Drops
The likelihood of expired cough drops causing acute toxicity is generally low. Active ingredients like menthol or dextromethorphan usually do not chemically degrade into acutely harmful substances. The primary safety concern is not chemical transformation but rather the potential for microbial growth.
The hard, low-moisture composition naturally resists contamination, but improper storage introduces risks. If the packaging is compromised or the drops are exposed to excessive humidity, they absorb moisture. This moisture provides an environment where mold or bacteria can thrive, leading to surface contamination that could cause illness.
Non-active components, such as oils and flavorings, can go rancid or break down over extended periods. While this process mostly results in a bad taste, it signals product degradation. If a drop shows any visual signs of mold, discoloration, or smells distinctly “off,” it should be discarded immediately.
How Efficacy Degrades Over Time
The expiration date indicates when the manufacturer can no longer guarantee the full medicinal strength of the active ingredients. Over time, the compounds responsible for the therapeutic effect diminish through chemical degradation or volatilization. Menthol, which provides the soothing, cooling sensation by acting as a topical anesthetic, is a volatile organic compound.
As the years pass, menthol slowly evaporates from the lozenge, reducing the concentration available to soothe the throat. This loss of potency means that while an expired drop is safe to consume, it offers little relief for a cough or sore throat. For lozenges containing cough suppressants like dextromethorphan, chemical breakdown reduces the amount of medication delivered. An expired drop may not deliver the minimum effective dose required, making it ineffective for its intended purpose.
Observable Physical Changes
Long before a drop becomes unsafe, it displays clear physical signs that its quality has been compromised. The sugar base is susceptible to environmental changes, leading to crystallization or “blooming” on the surface. This process changes the texture, causing the drops to appear cloudy or grainy.
Exposure to warm temperatures or high humidity can cause the drops to become sticky, soft, or fuse together inside the wrapper. Flavor degradation is also common, as volatile flavor oils and colorings break down, leading to a stale or unpleasant taste. These sensory changes indicate that the lozenge is past its peak quality.
Storage Guidelines and Safe Disposal
To maximize the shelf life and effectiveness of cough drops, store them in a cool, dry location, shielded from direct sunlight and excessive heat. Avoid areas like a bathroom cabinet or near a kitchen stove, as temperature fluctuations and humidity accelerate degradation. Following storage instructions helps ensure active ingredients remain potent until the expiration date.
When disposing of expired or unwanted cough drops, the FDA recommends using a drug take-back program, if available. If a take-back option is not accessible, lozenges can be disposed of in the household trash by first making them unappealing to children or pets. This involves:
- Mixing the drops with an undesirable substance, such as used coffee grounds, dirt, or cat litter, without crushing them.
- Sealing the mixture in a plastic bag or container before placing it in the trash.
- Removing any personal information from the original packaging.