- A review has found that insulin may not be as sensitive to temperature as was thought.
- Insulin typically requires refrigeration so that it doesn’t degrade and become less potent.
- However, the study found that some insulin types can be stored at room temperature.
- According to the researchers, insulin can be stored for longer periods.
- These findings could create greater flexibility and access for diabetes management.
Insulin may be less sensitive to temperature than has generally been believed, according to a new Cochrane review published on November 3.
Currently, insulin is stored under refrigeration so that it does not degrade and become less effective.
However, the study authors report that insulin stored at room temperature for months does not lose its potency.
Insulin is a hormone made in the beta cells of the pancreas that helps the body use or store blood sugar.
People living with diabetes either have trouble producing insulin or using what they do make. This can lead to high levels of glucose in the blood. Over time, this can damage the blood vessels, eyes, kidneys, and nerves.
Insulin is a vital medication for those who cannot produce enough to meet their needs and it must be injected multiple times throughout the day, generally prior to meals.
However, if people do not have reliable access to refrigeration, it can be difficult to store insulin properly, making it harder to treat their condition.
Given the difficulty of keeping insulin refrigerated, the researchers wanted to investigate whether storing insulin at temperatures either above or below what is currently recommended would affect the potency of the product.
They also wanted to look at the effects of storing it for longer periods of time than currently advised.
They selected one pilot clinical study and 16 laboratory studies that met their criteria. They also obtained previously unpublished information from manufacturers.
These included studies related to insulin vials, cartridges/pens, and prefilled syringes. However, there was no data for insulin pumps.
When they summarized the findings of these studies, it was found that unopened vials and cartridges of certain types of insulin can be stored at up to 25 degrees Celsius (77 degrees Fahrenheit) for up to six months.
Additionally, they can be held at 37 degrees Celsius (98.6 degrees Fahrenheit) for up to two months.
One study that mimicked the daily temperature fluctuations of tropical countries found that when temperatures varied between 25 and 37 degrees Celsius the medication could last up to three months without any significant decline in insulin activity.
The report also states that there was consistent potency at temperatures ranging from 4 degrees Celsius (39.2 degrees Fahrenheit) to 37 degrees Celsius. There was no data, however, for colder conditions.
Registered nurse Angie Victorio from DiaBettr.com, a certified Diabetes Care and Education Specialist (CDCES), who was not involved in the review, said, “If insulin is less temperature sensitive, that would basically reverse the current thinking and practice of storing insulin.”
These new findings could mean that insulin stored at warmer temperatures could last just as long as in the refrigerator, she stated.
According to the Diabetes Disaster Response Coalition (DDRC), the current recommendation for storing insulin is to keep it cool.
It is advised to keep it in a refrigerator that is maintained between about 36 to 46 degrees Fahrenheit. It should never be frozen.
They additionally state that if insulin is kept in the above-mentioned range it maintains its potency until the expiration date on the package.
The organization states that vials or cartridges, whether opened or unopened, can be left unrefrigerated between 59 and 86 degrees Fahrenheit for up to 28 days assuming they have not been diluted or taken out of the original vial. In these cases, they should be discarded within two weeks.
Insulin in the reservoir, tubing, or catheters of a pump device remains usable for only 48 hours. Additionally, if it’s exposed to temperatures above 98.6 degrees Fahrenheit it must be thrown away.
DDRC further notes that insulin should not be exposed to extreme temperatures as this will reduce its effectiveness. This means it should not be stored near a heat source or in direct sunlight.
Victorio said one of the main effects of these findings is that they would give people more options and flexibility when it comes to traveling with insulin.
“Storing insulin at home is easy where we have fridges but when traveling for more than a day [it] can be tricky,” she said. “But if insulin is less sensitive to temperature, then it can make travel easier because you’ll need less cooling.”
Victorio explained that this could mean something like being able to carry your insulin in your purse or luggage instead of needing an insulin cooler.
“Plus, injecting cold insulin can be uncomfortable so being able to keep insulin [at] room temperature for longer can help deal with this,” she said.
Dr. Mo Janson, a general practitioner and medical content creator for Welzo.com, who also was not involved in the review, pointed to the fact that it will reduce waste.
“If insulin vials or pens are accidentally left out of the fridge for longer than recommended, they might still retain their efficacy, leading to less waste of this essential medication,” he stated.
Janson also noted that these findings can make transport more accessible. “In areas where cold chain logistics are a challenge, this could lead to more straightforward transportation and distribution processes,” he explained, “ensuring that more people have access to this life-saving medication.”
Janson further stated that these findings could lead to broader access around the world.
“This is particularly significant,” he concluded, “as the global incidence of diabetes is rising, and many affected individuals live in low-to-middle-income countries.”
A new review indicates that insulin may not be as sensitive to temperature as was previously thought.
Current guidelines require that it remain refrigerated until it is needed and then discarded after 28 days or less, depending on how it is used.
These new findings could reverse the current thinking on insulin storage allowing it to be stored for longer periods at room temperature.
This could make it easier to travel with insulin since a cooler would not be required.
It would also reduce waste since people would not have to throw away insulin accidentally left out of the refrigerator.
Finally, it would increase access in areas of the world where reliable refrigeration is not always available and make it easier to maintain treatment.