Canagliflozin: What It Is and Why People Take It
Canagliflozin (brand name Invokana) is an SGLT2 blocker used mainly for type 2 diabetes. It lowers blood sugar by helping the kidneys remove extra glucose in urine. Many people use it when metformin alone doesn’t reach targets or when they need added heart and kidney protection that some studies have shown.
How it works, who should consider it, and dosing basics
Canagliflozin reduces blood sugar without causing much low blood sugar by itself. The usual start is 100 mg once a day before your first meal. If more control is needed and your kidneys work well, a doctor may raise it to 300 mg. Your kidney function (eGFR) matters: doctors check it before starting and during treatment. If eGFR is low, canagliflozin might not be appropriate for glucose control.
This drug can be helpful if you also have high cardiovascular risk or early kidney disease — talk with your clinician about whether the benefits apply to you. Don’t use it in type 1 diabetes, and avoid during pregnancy or breastfeeding.
Common side effects and safety checks
Expect a few predictable side effects: more urination, thirst, and higher risk of genital yeast infections. Some people get urinary tract infections. Less common but important problems include dehydration, low blood pressure (especially if you take diuretics), and a rare form of diabetic ketoacidosis that can happen even with normal blood sugar — know the signs: nausea, belly pain, fast breathing, confusion.
The CANVAS trial flagged a higher rate of lower-limb amputations with canagliflozin in some patients. That risk seems small but real; if you have peripheral artery disease, ulcers, or poor circulation, discuss this with your doctor and check feet regularly. Also tell your prescriber about other medicines (diuretics, insulin, sulfonylureas) because dose changes or extra monitoring may be needed.
Before starting, get a baseline kidney test, blood pressure check, and a review of foot health. If you become faint, dizzy, or have sudden leg pain, seek care quickly.
Safe buying tips and practical advice
Can you buy canagliflozin online? Yes, but do it safely. Always use a licensed pharmacy and get a prescription from a real clinician. Look for clear contact info, pharmacist access, and positive reviews. Avoid sites that sell without a prescription or offer suspiciously low prices. Keep your medication in a cool, dry place and follow storage directions on the package.
Practical tips: take it before breakfast, stay hydrated, check your blood sugar and weight regularly, and schedule kidney tests as advised. If you plan surgery or will be fasting, tell your care team — temporary stopping may be needed to reduce risks.
If you have questions about whether canagliflozin fits your care plan, bring a list of medications and health issues to your next visit. A short conversation with your clinician clears up most worries and helps you use the drug safely.
