Canagliflozin: what it does and who it helps

Canagliflozin (brand name Invokana) is an SGLT2 inhibitor used mainly for type 2 diabetes. It lowers blood sugar by letting your kidneys remove more glucose in the urine. Besides glucose control, it can help lower blood pressure, cause modest weight loss, and protect the heart and kidneys in many people. That's why doctors prescribe it not just for A1c numbers but for overall health in people at risk of heart or kidney problems.

How to take canagliflozin

Typical dosing is 100 mg once daily, taken before your first meal. If more glucose lowering is needed and your kidney function is good, your doctor may increase the dose to 300 mg once daily. You must have a prescription and baseline blood work before starting—especially an eGFR to check kidney function. Canagliflozin is not a safe choice for everyone. If you have type 1 diabetes, active ketoacidosis, or severely reduced kidney function, your provider will likely choose a different therapy.

Practical tips: take it in the morning before breakfast, keep taking other diabetes meds unless your prescriber tells you otherwise, and carry a list of all your medicines in case of emergencies. If you have surgery scheduled, your doctor may ask you to stop canagliflozin about 3 days before the procedure to lower the risk of ketoacidosis.

What to watch for and when to call your doctor

Canagliflozin has a few side effects you should know about. The most common are genital yeast infections and urinary tract infections. These happen because there’s more sugar in the urine. Drink enough water and watch for itching, discharge, or painful urination.

Less common but serious issues include dehydration, low blood pressure, and diabetic ketoacidosis (DKA) that can occur with normal blood sugar (called euglycemic DKA). If you feel faint, dizzy, very thirsty, have fast breathing, belly pain, or unusual tiredness, seek care right away. Some large studies flagged a higher rate of leg and foot amputations—if you have peripheral artery disease, foot ulcers, or numbness, talk to your doctor before starting canagliflozin and check your feet daily.

Also expect your provider to monitor kidney function, blood pressure, and electrolytes. If you use a diuretic, insulin, or sulfonylurea, your risk of low blood pressure or low blood sugar may rise, so doses may need adjusting. Pregnant or breastfeeding people should avoid this drug unless a specialist advises otherwise.

Bottom line: canagliflozin can help lower A1c and protect the heart and kidneys for many people with type 2 diabetes. But it comes with specific risks and monitoring needs. Talk to your prescriber about kidney tests, foot checks, and what symptoms to watch. If anything feels off after starting the drug, call your clinic—early action prevents most problems.