Metformin alternatives

Can't take metformin or it stopped working? That happens. People stop metformin because of stomach side effects, low kidney function, or because blood sugar needs extra help. Good news: there are several clear alternatives. Below I explain the main options, how they differ, and what to ask your provider so you can make a smart choice quickly.

Main drug classes and what they do

SGLT2 inhibitors (eg, empagliflozin, canagliflozin): These lower blood sugar by letting the kidneys remove extra glucose in urine. Big benefits: weight loss in many people and heart and kidney benefits shown in studies. Watch for genital infections, dehydration, and discuss kidney function with your doctor.

GLP-1 receptor agonists (eg, liraglutide, semaglutide): These are injectable (some now come as weekly doses) that slow digestion, reduce appetite, and cut A1c effectively. Many people lose weight on these. Side effects tend to be nausea at first; they can be more costly and need a conversation about injection use.

DPP-4 inhibitors (eg, sitagliptin): These are pills that modestly lower A1c and have few side effects. They’re weight neutral and don’t usually cause low blood sugar. They’re a gentler option if you need something simple and well tolerated.

Sulfonylureas (eg, glimepiride, glyburide): These older pills are effective and cheap but can cause low blood sugar (hypoglycemia) and sometimes weight gain. They still have a role when cost is a key factor and monitoring is possible.

Thiazolidinediones (eg, pioglitazone): These improve insulin sensitivity and work well for some people. Downsides include fluid retention, possible weight gain, and concern in those with heart failure. Your doctor will weigh benefits vs risks carefully.

Alpha-glucosidase inhibitors (acarbose, miglitol): These slow carbohydrate absorption in the gut and can help with post-meal blood sugar spikes. Common side effects are gas and bloating. They can be helpful if digestive tolerance is okay.

Insulin: When A1c is high or other meds aren’t enough, insulin remains the most powerful option to lower blood sugar quickly. Modern insulin regimens can be flexible; they require learning about dosing and monitoring.

How to pick the right option

Start by checking a few facts: current A1c, eGFR (kidney function), weight goals, heart or kidney disease, budget, and how you feel about injections. If you have heart disease or kidney risk, ask about SGLT2s or GLP-1s. If cost or simplicity matters, DPP-4s or sulfonylureas may fit. If metformin is stopped because of low eGFR, doctors often avoid it when eGFR is under about 30 mL/min/1.73 m2.

Talk to your clinician about side effects, monitoring needs, and insurance coverage. If changing meds, expect follow-up labs and a plan to adjust dose based on response. Small checks—weight, blood sugar logs, and symptoms—help you and your provider pick the best path fast.

Have specific concerns or a current medication list? Share them with your clinician — the right choice depends on your health, not just the drug name.