Insulin is a hormone that plays a central role in managing blood glucose levels for individuals with diabetes. Its ability to facilitate the uptake of sugar from the bloodstream into cells is fundamental to health. Maintaining the effectiveness of insulin relies heavily on proper storage, as this delicate medication is sensitive to environmental conditions.
How Freezing Damages Insulin
Freezing damages insulin’s protein structure. When insulin solutions freeze, water molecules form ice crystals. These ice crystals can physically disrupt the insulin protein’s structure.
The process of freezing also concentrates solutes in the unfrozen water phase, which can alter the pH and ionic strength around the protein, leading to denaturation. Denaturation refers to the unfolding or breakdown of the protein, rendering it unable to function as intended. Even if the insulin thaws and appears normal, its molecular integrity has been compromised, meaning it cannot regain its original potency.
Consequences of Using Frozen Insulin
Using insulin that has been frozen and then thawed is ineffective. The structural damage caused by freezing prevents the insulin from properly lowering blood glucose levels. This ineffectiveness can lead to hyperglycemia, or dangerously high blood sugar.
Uncontrolled high blood sugar can manifest in symptoms such as increased thirst, frequent urination, fatigue, and blurred vision. In severe instances, prolonged hyperglycemia can progress to diabetic ketoacidosis (DKA), a serious complication that requires immediate medical attention.
What to Do If Your Insulin Freezes
If insulin accidentally freezes, do not use it. Discard the compromised insulin immediately to prevent accidental use.
Contact a healthcare provider or pharmacist for guidance on obtaining a new supply of insulin. They can also provide advice on managing blood sugar levels during the interim period until a fresh supply is secured.
Preventing Insulin Freezing
Proper storage is important for maintaining insulin integrity and preventing it from freezing. Unopened insulin should be stored in a refrigerator at temperatures between 36°F and 46°F (2°C and 8°C). Once opened, vials or pens can be kept at room temperature, between 59°F and 86°F (15°C and 30°C), for up to 28 days, though specific recommendations may vary by brand.
To avoid freezing, never store insulin directly next to freezer compartments, in a car during cold weather, or in checked airplane luggage, as cargo holds can reach freezing temperatures. Also, avoid placing insulin near air conditioning vents or other areas prone to extreme cold. Using an insulated container for transport can help protect insulin from temperature extremes without direct contact with ice packs.