Insulin is a hormone that plays a central role in managing blood sugar levels for individuals with diabetes. It helps the body’s cells absorb glucose from the bloodstream, converting it into energy or storing it for later use. Its delicate protein structure makes proper function highly dependent on careful handling and storage.
How Insulin Changes Over Time
Insulin is a protein-based medication that degrades over time or when exposed to certain conditions. This degradation causes insulin to lose effectiveness in lowering blood sugar. Factors accelerating this breakdown include temperature fluctuations, light exposure, and physical agitation. For example, freezing insulin or exposing it to high temperatures, like leaving it in a hot car, can cause it to spoil. Shaking insulin vigorously also diminishes its potency.
Visual inspection often reveals signs of degraded insulin. Clear insulin, which should be colorless and free of particles, may become cloudy, discolored, or develop clumps, threads, or crystals. While some insulin types are naturally cloudy, they should be uniformly so, without visible particles or clumping. These physical changes indicate the insulin’s protein structure has been compromised, meaning it will not work as intended, even if within its printed expiration date.
Health Consequences of Using Compromised Insulin
Using insulin that has lost its potency poses direct health risks, primarily leading to hyperglycemia, or high blood sugar. When insulin is ineffective, the body’s cells cannot properly absorb glucose, causing blood sugar levels to remain elevated. Initial symptoms of hyperglycemia include increased thirst, frequent urination, fatigue, and blurred vision. These symptoms develop gradually over several days or weeks.
If high blood sugar persists, it can lead to more severe complications. For individuals with type 1 diabetes, using ineffective insulin significantly increases the risk of diabetic ketoacidosis (DKA), a life-threatening condition where the body produces harmful acids called ketones. Prolonged hyperglycemia can contribute to long-term health problems affecting various organs, including nerve damage, kidney issues, and cardiovascular disease. A break in sterile conditions, such as improper handling or storage leading to contamination, could introduce a rare risk of infection.
Safe Handling and Disposal
Proper storage maintains insulin’s effectiveness. Unopened insulin vials and pens should be stored in a refrigerator at 2°C to 8°C (36°F to 46°F) until their expiration date. Once opened, most insulin products can be stored at room temperature, generally between 15°C and 30°C (59°F and 86°F), for about 28 days, though this can vary by brand and type. It is important to protect insulin from direct heat, freezing temperatures, and direct sunlight, as these conditions can accelerate degradation.
Always check the expiration date on unopened insulin and note the date of opening for insulin in use. If insulin appears discolored, cloudy (for clear types), or contains any clumps or particles, it should not be used. If there is any suspicion that insulin is compromised, it should be safely discarded.
For disposal of needles and syringes, a designated sharps container is recommended. These are puncture-resistant containers, often available from pharmacies or medical supply stores, or a heavy-duty plastic container with a tight-fitting lid can be used. Once full, the container should be sealed and disposed of according to local guidelines, which may involve community drug take-back programs or specific instructions from waste management. Consulting a healthcare provider for any concerns about insulin effectiveness or accidental use of compromised insulin is a prudent step.