How Shaking & Heat Can Damage Your Insulin

What This Study Found

A 2025 laboratory study published in the journal Proteins looked at what happens to human insulin when it is exposed to heat and physical stress at the same time. Researchers found that when insulin was shaken or pumped at high speeds while also being exposed to temperatures of 60°C (140°F), it broke down very quickly — losing its normal shape within just 2 minutes. This kind of damage caused the insulin to clump together into abnormal structures that could no longer work properly and may even be harmful to cells.

Why Does This Matter to You?

You may not think much about what happens to your insulin before it reaches you, or even how you handle it at home. But this study is a reminder that insulin is a fragile molecule. It depends on keeping its precise shape to do its job — lowering your blood sugar safely and effectively.

Here are the key situations where insulin can be put at risk:

• Shipping and transport: Insulin sent through the mail or transported in warm vehicles can be exposed to both heat and physical movement at the same time — exactly the conditions studied here.
• Insulin pumps: Insulin in a pump is constantly being pushed through tubing. If the pump or insulin gets too warm, this study suggests the combination could speed up breakdown.
• Improper storage at home: Leaving insulin in a hot car, near a sunny window, or shaking a vial vigorously before use can all contribute to stress on the medication.

What the Researchers Actually Measured

The scientists tested insulin under different levels of physical stress (called shear rates) and four different temperatures. At the highest stress level combined with 60°C heat, the insulin's normal spiral-shaped structure (called an alpha-helix) dropped from a healthy level down to just 16% of normal — in only 2 minutes. They also found that the time it took for the insulin to start forming damaging clumps was cut by 80 times compared to insulin that wasn't physically stressed.

Cell tests showed that insulin exposed to these extreme conditions reduced cell survival to just 53%, suggesting that badly degraded insulin could potentially cause harm rather than help.

Important Limits of This Study

It's worth noting that the most dramatic results happened at 60°C — much hotter than normal room temperature or body temperature. These were laboratory conditions designed to stress-test insulin quickly. Still, the findings support what diabetes educators have long recommended: protect your insulin from heat and handle it gently.

What You Can Do

• Store unopened insulin in the refrigerator (36°F–46°F / 2°C–8°C).
• Keep in-use insulin at room temperature but away from heat and direct sunlight.
• Never leave insulin in a hot car or near a heat source.
• Roll insulin vials gently rather than shaking them.
• Check insulin for cloudiness or clumping before each use — if it looks off, don't use it.
• When ordering insulin online, choose a supplier that uses proper cold-chain shipping.

How MDS Diabetes Can Help

At MDS Diabetes, we understand that your insulin supply is only as good as the care taken to protect it. Visit mdsdiabetes.com to explore our range of insulin storage solutions, cooling cases, and diabetes management supplies designed to help you keep your medications safe — whether you're at home or on the go.

Citation: Panda, Kumar, Gupta (2025). Shear-Induced Structural Changes Drive Amorphous Aggregate Formation of Human Insulin. Proteins. PMID: 40583251. DOI: 10.1002/prot.70015