The newer insulins work faster and are easier to use, but the older ones tend to be more affordable.

Some people with diabetes in the to Mexico or Canada, where insulin is sold at a fraction of the U.S. cost. Others ration insulin, a risky move that can lead to a host of medical problems, including mood swings, severe dehydration, increased infection risk, kidney and eye problems, limb amputation and even death. In many cases, people like Wilkerson switch from the expensive but easier-to-use “analogue” human insulins to the more-difficult-to-use traditional insulins (we’ll explain the difference later) but then struggle to correctly time and partition each dose. Here’s why this switch can be so challenging and how medical professionals can help patients do it safely.

When people eat a meal, their blood sugar, or glucose, rises. Like a traffic cop, insulin enters the bloodstream, where it signals cells to absorb these sugars, so that the nutrients can then be used for energy. If they didn’t take insulin, people with diabetes would experience high blood sugar, or hyperglycemia, after eating.

The newer insulins work faster and are easier to use, but the older ones tend to be more affordable.“[Insulin’s] job is to prevent the rise in sugar after a meal or after stress,” said Doctor. People with type 1 diabetes, whose bodies may make no insulin, “have a finer margin of error, where if they take too much [insulin], they can cause severe low glucose,” Wyne told Live Science. In contrast, people with type 2 diabetes make some insulin in their bodies but not enough (and usually less as they age). Diabetes used to be a death sentence. But it became a treatable, chronic condition after two Canadian scientists extracted active insulin from an animal pancreas in 1921. They treated their first patient in 1922 and later sold their patented technique to the University of Toronto for $1, saying that their goal was not profit but rather public health.

Old vs. new

Before the newer insulins came onto the market, people with diabetes would get their insulins in a vial and deliver them with a syringe, injecting either a regular (also known as short-acting or “R”) insulin before a meal and “neutral protamine Hagedorn” (of NPH, an intermediate-acting insulin) once or twice a day. Regular insulin had to be taken about 30 minutes before a meal, so people had to know when they were eating, Wyne said. People with diabetes could also get a vial that had a mixture of regular and NPH insulin, which decreased daily injections, she said. Wyne remembers insulin prices started creeping up with the 1996 introduction of the short-acting insulin Humalog, made by Eli Lilly. Because it worked within 15 minutes, Humalog allowed people to inject insulin right as they sat down to eat. Humalog was the first analogue (meaning it’s lab grown) insulin that came onto the market. It initially sold for $21 a vial, about a month’s supply, Wyne said. Over the next 20 years, that price increased more than 30 times, and five injector pens.

If people are unsure how to convert from the newer brands and pens to the traditional vial and syringe, “you might not do it right,” Wyne said. “How are you going to get a hold of your doctor and get the information on how to make the conversion?” Given how complicated it is, the doctor will likely ask patients to schedule a visit, but people without insurance often can’t afford to do that, Wyne said. So, Wyne and her colleagues are now trying to guess who might be losing their insurance, either because these patients are aging off their parents’ insurance plans or because they’re in a precarious situation. “Obviously, we don’t know who is going to lose their insurance,” she said. “But we need to be aware that they need the information in case that happens.”Wyne encouraged people with diabetes to alert their doctors if a change in insurance coverage is expected. Likewise, by educating patients about how to use vials and syringes, telling them how to take advantage of price-checking services such as GoodRx, and advising against the dangerous practice of rationing, doctors could save lives, Wyne said.