In one 26-week study, those on Invokana lost about 6 to 8 pounds, while those in the placebo group lost only about a pound.
But the drug has side effects, including infections of the urinary tract, penis, and vagina. This leads some experts to have less enthusiasm for the new medicine.
It will also cost a lot more than other diabetes drugs. The wholesale cost for Invokana is $8.77 a pill, according to Katie Mahony, a spokeswoman for Janssen. Retail cost for the 100-milligram starting dose, without co-pays or coverage, is about $10 a pill, or $300 a month.
The popular diabetes drug metformin can cost as little as 25 cents a pill.
"It's another way to control diabetes without injections," says Anthony McCall, MD. He is the James M. Moss Professor of Medicine at the University of Virginia School of Medicine in Charlottesville. He was not involved in the development of the new drug.
A new pill is welcome, McCall says, for some of the estimated 24 million Americans with type 2 diabetes, especially as an alternative to injecting insulin.
"People do have strong feelings about injectable medications," he says. However, he and other experts say they don't expect Invokana to replace other drugs, but rather to offer another option.