Ever since he was diagnosed with type 1 diabetes in college, not a day has gone by when Scott Ruderman hasn’t injected insulin into his body. It’s an expensive daily ritual, but he has little choice. “After a few days without it, I’d die,” the 33-year-old said.

A few years ago, when he and his partner were visiting family in Canada, they walked by a pharmacy that offered the drug at a fraction of the cost that he was used to paying. “We went inside and the pharmacist brought out all the different vials from all the different companies,” he said. “I was like: Oh my God. I’m actually feeling accepted in another country that’s not mine.”

The vial he purchased, which would be a two-and-a-half-week supply, cost C$19, compared with the $300-400 he was used to paying in the US. “I was happy,” he recalled, “but […]