Top Diabetes Drug: Why Metformin Is the Most Popular Medication

• By Arjun Deshpande
• 16 Oct, 2025
• 0 Comments

When you hear people talk about the "go‑to" drug for diabetes, the name that pops up almost every time is Metformin. It isn’t a coincidence - this old‑school, inexpensive pill still dominates prescriptions worldwide, even after more than six decades on the market.

What makes a medication "most popular"?

Popularity isn’t just about sales numbers. It’s a mix of prescription volume, safety profile, cost, and how well a drug fits into everyday life. To understand why Metformin tops the chart, we first need to know the landscape of diabetes treatment.

Quick Snapshot of Diabetes Medication Classes

Diabetes drugs fall into several families, each targeting a different part of the glucose‑control puzzle. Below is a high‑level look at the five most common groups.

Meet the Champion: Metformin

Metformin is a biguanide oral medication that lowers blood glucose primarily by reducing liver glucose output and enhancing peripheral insulin sensitivity. It was first approved in the United States in 1995 and quickly became the first‑line therapy for type 2 diabetes.

• Prescribed to roughly 150million people worldwide (WHO estimate 2024).
• Cost per month often under $10 in generic form, making it the most affordable option.
• Low risk of hypoglycemia when used alone.
• Potential modest weight loss, which helps many patients stay motivated.
• Extensive safety data: decades of real‑world use with a well‑characterized side‑effect profile.

Because of these factors, most national guidelines - from the American Diabetes Association (ADA) to the World Health Organization (WHO) - place Metformin at the top of the treatment ladder.

Why Some Patients Can't Take Metformin

Even a superstar drug has its limits. Common reasons for intolerance include gastrointestinal upset (nausea, diarrhea) and, rarely, a serious condition called lactic acidosis. About 5‑10% of patients discontinue within the first few months.

Doctors often mitigate side effects by starting at a low dose (e.g., 500mg once daily) and using the extended‑release formulation, which reduces stomach irritation.

Alternatives When Metformin Isn’t Enough

If blood sugar remains above target despite the maximum tolerated Metformin dose, physicians consider add‑on therapies. The choice depends on factors like cardiovascular risk, kidney function, weight goals, and cost.

• Sulfonylureas are cheap but can cause hypoglycemia and weight gain.
• GLP‑1 receptor agonists (e.g., semaglutide) deliver strong glucose reduction and weight loss but are pricey and injectable.
• SGLT2 inhibitors (e.g., empagliflozin) protect the heart and kidneys, yet they increase risk of urinary tract infections.
• For patients with advanced disease, insulin remains the most reliable way to achieve tight control.

Prescription Trends: Numbers that Tell a Story

Data from the IQVIA National Prescription Audit (2023) show Metformin accounting for 31% of all diabetes prescriptions in the United States, far ahead of the next best - sulfonylureas at 12%.

Globally, a 2024 WHO report notes that in low‑ and middle‑income countries, Metformin captures over 45% of the diabetes drug market, largely because of its low price and inclusion on national essential‑medicine lists.

Safety & Monitoring: What Patients Should Know

Before starting Metformin, doctors check kidney function (eGFR). The drug is contraindicated if eGFR falls below 30mL/min/1.73m². Routine labs every 3‑6 months help catch any emerging issues.

Common side effects - mild stomach upset - often fade within a few weeks. If they persist, patients can switch to the extended‑release form or a different class altogether.

Future Outlook: Will Metformin Stay on Top?

Newer agents keep pushing the envelope on cardiovascular and renal benefits. However, none have combined Metformin’s affordability, decades‑long safety record, and ease of use.

Research is exploring Metformin for non‑diabetic uses - like aging, cancer prevention, and polycystic ovary syndrome - which may further cement its status as a versatile drug.

Key Takeaways

• Metformin remains the most prescribed diabetes medication worldwide due to cost, safety, and efficacy.
• Guidelines from major health bodies place it as first‑line therapy for type 2 diabetes.
• Side effects are usually mild; extended‑release versions improve tolerability.
• When Metformin alone isn’t enough, clinicians add sulfonylureas, GLP‑1RAs, SGLT2 inhibitors, or insulin based on individual risk profiles.
• Its dominance is likely to continue, even as newer, more expensive drugs enter the market.