Early in Tuesday night’s presidential debate, President Donald Trump claimed he had drastically lowered the price of insulin, a lifesaving drug taken in some form by more than 7 million Americans with diabetes.

“Insulin, it was destroying families, destroying people. The cost,” the president said. “I’m getting it for so cheap, it’s like water.”

That came as a shock to the Americans who shell out hundreds of dollars a month on insulin, a number of whom posted triple-digit pharmacy bills to social media after the president’s assertion.

“I looked at my husband and slapped my leg and said, ‘Can you believe that!’ ”said Tiffany Garrioch, 36, a public health nurse and educator in Minnesota with Type 1 diabetes. “To hear the president say it costs as much as water makes us look like we’re crybabies or liars.”

Insulin costs her $36.76 a day, she said. In 2008, it was $9.81.

Insulin prices have ballooned over two decades, including during the Trump administration. A subset of people enrolled in Medicare drug plans that cap payments at $35 a month are insulated from those costs. Otherwise a patient with diabetes can spend hundreds of dollars on a monthly insulin supply.

A few decades ago, people could pay about $20 per month for insulin, said Jeremy Greene, a primary care physician and medical historian at Johns Hopkins University. “Insulin prices have been a travesty of American pharmaceutical policy.”

About 1 in 4 patients with diabetes report underusing insulin because of financial pressure, which “effectively means that they are trying to make their insulin stretch, or having difficulty buying groceries or paying utility bills,” physician Jing Luo said.

Switching to cheaper but less effective forms of insulin, or rationing it, can be devastating. “The consequence of the untenable price of insulin can be measured in body counts,” Greene said.

Three companies — Eli Lilly, Novo Nordisk and Sanofi — dominate the market. Insulin sold by Novo Nordisk, under the brand name NovoLog, was priced at $40 per vial in 2001 and rose to $289 in 2018, as the Washington Post reported last year. Eli Lilly’s Humalog insulin was $275 a vial as of last year, up from $21 when it entered the market in 1996. Sanofi’s Lantus was up to $270 a vial last year from $35 when it debuted in 2001. A box of Lantus exceeds $1,000 in the U.S., Luo pointed out, “yet that same box lists under $100 at any Canadian pharmacy without a prescription.”

The three drugmakers have reduced the cost of insulin for some patients who have lost jobs, health insurance or both as a result of the pandemic. But attempts to encourage the industry to rein in insulin prices have been largely unsuccessful, Greene said.

This year, the Food and Drug Administration approved a generic biologic form of a long-lasting insulin drug, which can be purchased for about a third of the price of the brand-name equivalent. This was progress — but “not progress attributable to Trump,” Greene said.