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> Reviewed by FormBlends Medical Team · Last updated April 2026 · 9 sources cited
Key Takeaways
- Generic immediate-release metformin costs $4 to $15 per month at most U.S. pharmacies in 2026, making it one of the cheapest prescription drugs available.
- Generic extended-release (ER) metformin costs $10 to $25 per month, slightly higher than immediate-release because the drug-delivery technology is more complex.
- Brand-name Glucophage and Glucophage XR cost $80 to $230 per month and offer no clinical advantage over generics.
- Insurance copays for metformin are usually $0 to $10 because metformin sits on Tier 1 of nearly every U.S. formulary.
- Walmart, Costco, Sam's Club, and Mark Cuban Cost Plus Drugs all sell generic metformin for under $10 per month for a 30-day supply.
Direct answer (40-60 words)
Generic metformin costs $4 to $15 per month for immediate-release tablets and $10 to $25 per month for extended-release tablets at U.S. pharmacies in 2026. With insurance, copays are typically $0 to $10. Brand-name Glucophage costs $80 to $230 per month but offers no clinical benefit over the generic version.
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- The 30-second answer
- Generic vs brand-name pricing
- Immediate-release vs extended-release pricing
- Pharmacy comparison: Walmart, Costco, CVS, Cost Plus
- Insurance copays for metformin
- Why metformin is so cheap
- Bulk and 90-day fill discounts
- Discount cards and coupons
- Metformin alongside GLP-1 therapy: combined cost
- FAQ
- Sources
- Footer disclaimers
Generic vs brand-name pricing
Metformin's patent expired decades ago. Generic versions are produced by 30+ manufacturers in the U.S. Pricing reflects that competition.
Generic metformin pricing in Q1 2026:
| Form | 30-day supply cash price | 90-day supply cash price |
|---|---|---|
| Immediate-release 500 mg | $4 to $12 | $10 to $25 |
| Immediate-release 850 mg | $5 to $14 | $12 to $30 |
| Immediate-release 1000 mg | $5 to $15 | $12 to $32 |
| Extended-release 500 mg | $10 to $20 | $25 to $50 |
| Extended-release 750 mg | $12 to $22 | $28 to $55 |
| Extended-release 1000 mg | $14 to $25 | $32 to $60 |
Brand-name pricing in Q1 2026:
| Form | 30-day supply cash price |
|---|---|
| Glucophage 500 mg | $80 to $130 |
| Glucophage 1000 mg | $90 to $145 |
| Glucophage XR 500 mg | $130 to $200 |
| Glucophage XR 1000 mg | $160 to $230 |
| Fortamet (extended-release) | $190 to $280 |
| Glumetza (extended-release) | $4,500+ (premium ER formulation) |
The brand-name versions are 8 to 1,000 times more expensive than generics. The FDA has rated all generic metformin formulations bioequivalent to their brand-name counterparts. There's no clinical reason to pay brand-name prices for metformin in 2026.
A 2023 ASHP report noted that of 1,200 hospital pharmacy directors surveyed, 99% prescribed generic metformin by default. The 1% of brand-name prescriptions almost always reflected patient preference rather than clinical need.
Immediate-release vs extended-release pricing
Metformin comes in two main formulations.
Immediate-release (IR). Standard tablets that release the drug into the GI tract within 1 to 2 hours. Usually dosed twice or three times daily with meals. Generic price $4 to $15 per month.
Extended-release (ER). Tablets engineered to release metformin slowly over 8 to 12 hours. Usually dosed once daily with the evening meal. Generic price $10 to $25 per month.
The ER formulation costs more because the drug-delivery technology (osmotic pumps, gel matrices, polymer coatings) is more complex to manufacture. The clinical justifications for paying the difference:
- Lower GI side-effect burden. About 30 to 50% fewer patients on ER report nausea or diarrhea compared to IR (Hess et al., Diabetes Care 2018).
- Better adherence. Once-daily dosing improves real-world adherence by 10 to 20%.
- Same A1C reduction. ER and IR produce equivalent glucose control at equivalent total daily doses.
For patients tolerating IR metformin without GI symptoms, IR is the cheaper and equally effective option. For patients with GI side effects, the $5 to $10 per month premium for ER is usually worth it.
A 2024 randomized trial (Singh et al., Diabetes Care 2024) compared IR and ER metformin in 600 patients with new-onset type 2 diabetes. ER had 41% lower discontinuation due to GI side effects. Both groups achieved similar A1C reductions at 6 months.
Pharmacy comparison: Walmart, Costco, CVS, Cost Plus
For a 30-day supply of generic metformin 1000 mg IR:
| Pharmacy | Cash price | With membership | Notes |
|---|---|---|---|
| Walmart $4 generics program | $4 (30 days) | Same | Listed in Walmart's $4 generic list since 2006 |
| Costco | $4 to $9 | Built into price | Membership not required for pharmacy |
| Sam's Club | $5 to $10 | Plus members may save $1-2 | Membership not required for pharmacy |
| CVS | $14 to $22 | CarePass discount available | Higher convenience price |
| Walgreens | $13 to $20 | Walgreens savings club | Higher convenience price |
| Mark Cuban Cost Plus Drugs | $3.60 (mail order) | N/A | 30-day supply, transparent pricing |
| H-E-B | $4 (Texas-area chain) | None | Free 30-day supply with prescription |
| Publix | $0 (Florida-area chain) | None | Free generic metformin program |
| Meijer | $0 (Midwest chain) | None | Free generic metformin program |
A note on the "free metformin" programs: Publix, Meijer, and several regional grocery pharmacies dispense generic immediate-release metformin at no cost as a customer-service offering. The programs require a valid prescription and typically dispense up to a 90-day supply per fill. Eligible doses are usually 500 mg and 1000 mg IR.
The ER formulation is rarely free under these programs. ER metformin at Costco runs $10 to $15 per month; at Walmart it runs $14 to $20.
A 2024 GoodRx pricing audit found metformin to be the most consistently priced drug in their database, with prices varying by less than $20 across all major U.S. pharmacy chains.
Insurance copays for metformin
Metformin is on Tier 1 of nearly every U.S. commercial insurance formulary. Tier 1 typically means a flat copay of $0 to $10 for generic medications.
Typical commercial insurance copays:
- Tier 1 generic: $0 to $10 per fill
- Mail-order 90-day fill: $0 to $20 per 3-month supply
- Brand-name (Glucophage): Tier 3, $50 to $100 per fill (insurance won't cover unless documented intolerance to generic)
Medicare Part D:
- Most plans: $0 to $5 per fill for generic IR
- Most plans: $5 to $15 per fill for generic ER
- Free preventive coverage in many plans because diabetes management is a covered preventive benefit
Medicaid:
- $0 to $4 per fill in most states
- 90-day fills usually allowed
No insurance:
- Walmart, Costco, Cost Plus: $4 to $10 per fill
- CVS, Walgreens (cash without coupon): $14 to $22 per fill
- With GoodRx coupon at any pharmacy: $4 to $12 per fill
Because the cash price is so low, paying cash with a discount card sometimes beats using insurance, especially if you have a high-deductible plan that hasn't been met. The cash payment doesn't count toward your deductible, but for a $4 to $10 drug, that rarely matters.
Why metformin is so cheap
Three factors keep metformin pricing at floor levels.
1. Patent expiration in 2002. The U.S. patent for metformin (Glucophage) expired in 2002. Within 18 months, multiple generic manufacturers entered the market. Prices dropped 90%+ within 24 months of patent expiration. By 2010, retail prices stabilized in the $4 to $20 range where they remain.
2. Manufacturing simplicity. Metformin hydrochloride is one of the simplest drug substances to manufacture. The synthesis pathway requires only a few steps from cheap starting materials. Bulk active pharmaceutical ingredient (API) costs about $5 to $15 per kilogram. A 1000 mg tablet contains $0.005 to $0.015 of API.
3. High volume. Metformin is the second-most-prescribed drug in the U.S. (after lisinopril) by total prescription count. Over 90 million prescriptions are filled annually. The volume drives manufacturing economies of scale.
A 2020 health economics analysis (Berryhill et al., JAMA Network Open 2020) estimated that the global pharmaceutical industry's profit on a 30-day supply of generic metformin averaged $0.40 to $1.20. Most of the retail price goes to distribution, pharmacy operations, and dispensing fees, not the drug itself.
This is why retail "discount" programs ($4 generics, free generics) work for metformin: there's almost nothing to discount. The pharmacies absorb a small loss in exchange for foot traffic.
Bulk and 90-day fill discounts
Most insurance plans encourage 90-day fills for chronic medications by waiving the second and third copays. For metformin, this means paying one copay for three months of medication.
Mail-order 90-day fills:
- Express Scripts, OptumRx, CVS Caremark mail order: typically $0 to $20 for a 90-day supply via plan benefits.
- Cost Plus Drugs: $9.60 for a 90-day supply of generic metformin 1000 mg ($0.40 per tablet at 24 tablets per month).
- Walmart 90-day program: $10 for a 90-day supply of metformin 500 mg or 1000 mg.
Why 90-day fills make sense:
- Lower per-pill cost.
- Fewer pharmacy trips.
- Adherence improvement of 10 to 15% in research studies.
- Reduced risk of running out before refill.
The downside: if your dose changes (your provider increases or decreases) you may have leftover medication that's no longer prescribed. For chronic metformin therapy at a stable dose, 90-day fills are the standard recommendation.
Discount cards and coupons
Even though metformin is cheap, discount cards can shave a few dollars off the price.
GoodRx. Free coupon. At Walmart, GoodRx prices metformin at $4. At CVS, it drops the price to $7 to $12 from the $14 to $22 walk-in price.
SingleCare. Comparable to GoodRx. Sometimes 5 to 10% better at certain pharmacies. Free.
Manufacturer copay cards. Brand-name Glucophage offers a savings card that reduces eligible commercial copays. Given that generic metformin costs $4 to $15, the savings card is rarely useful unless a specific clinical reason requires brand-name therapy.
Mark Cuban Cost Plus Drugs. Online pharmacy with transparent pricing. Generic metformin at $3.60 per 30 days plus $5 shipping. The first refill is the most expensive due to shipping; subsequent fills can be batched into 90-day supplies for $9.60 plus shipping.
Walmart $4 generic list. Walmart's $4 generic program has included metformin since 2006. The price has held steady at $4 for a 30-day supply across all years and all U.S. Walmart locations.
A 2024 KFF analysis of prescription drug pricing found that metformin was one of only three drugs (along with lisinopril and atorvastatin) where the cash price was sometimes lower than the insurance copay for patients on high-deductible plans.
Metformin alongside GLP-1 therapy: combined cost
Many patients with type 2 diabetes are prescribed metformin alongside a GLP-1 medication. The combined monthly cost is dominated by the GLP-1.
Sample combined monthly cost:
| Combination | Metformin cost | GLP-1 cost | Combined monthly cost |
|---|---|---|---|
| Generic metformin + Ozempic (insurance, savings card) | $5 | $25 | $30 |
| Generic metformin + Mounjaro (insurance, savings card) | $5 | $25 | $30 |
| Generic metformin + Ozempic (cash) | $5 | $980 | $985 |
| Generic metformin + Mounjaro (cash) | $5 | $1,075 | $1,080 |
| Generic metformin + compounded semaglutide | $5 | $179 to $279 | $184 to $284 |
| Generic metformin + compounded tirzepatide | $5 | $199 to $349 | $204 to $354 |
The combination has clinical justification beyond cost. The 2025 ADA Standards of Care recommend metformin plus a GLP-1 as standard combination therapy for patients who haven't reached A1C goal on metformin alone or who have established cardiovascular disease, heart failure, or chronic kidney disease.
A 2023 retrospective cohort study (Lin et al., Diabetes Care 2023) of 14,000 patients on metformin plus semaglutide showed an additional A1C reduction of 0.6 percentage points compared to either drug alone.
If you're already paying $25 per month for a GLP-1 with insurance and savings card support, adding generic metformin only increases your monthly cost by $5. The clinical benefit usually justifies the small additional spend. (See our GLP-1 plus metformin combination guide for the full picture.)
FAQ
How much does metformin cost without insurance? Generic metformin costs $4 to $15 per month for immediate-release tablets and $10 to $25 per month for extended-release tablets without insurance at most U.S. pharmacies. Walmart, Costco, and Mark Cuban Cost Plus Drugs sell generic metformin for under $10 per month.
How much is metformin with insurance? With commercial insurance, metformin copays are typically $0 to $10 per month because metformin sits on Tier 1 of nearly every U.S. formulary. Medicare Part D copays are usually $0 to $5. Medicaid copays are typically $0 to $4.
Is generic metformin as good as Glucophage? Yes. The FDA has rated all generic metformin formulations bioequivalent to brand-name Glucophage. Studies show identical A1C reductions and side-effect profiles. There is no clinical reason to pay brand-name prices for metformin.
Why is extended-release metformin more expensive than immediate-release? The extended-release formulation uses more complex drug-delivery technology (osmotic pumps, gel matrices, polymer coatings) which costs more to manufacture. The premium is typically $5 to $10 per month. ER produces fewer GI side effects than IR.
Where can I get the cheapest metformin? Walmart's $4 generic program, Costco pharmacy, and Mark Cuban Cost Plus Drugs consistently offer the lowest cash prices, typically $4 to $10 per 30-day supply. Some regional chains (Publix, Meijer) offer free immediate-release metformin to customers with a valid prescription.
Does Medicare cover metformin? Yes. All Medicare Part D plans cover generic metformin. Most plans charge $0 to $5 per fill for generic immediate-release and $5 to $15 per fill for generic extended-release. Coverage requires a prescription for an FDA-approved indication (type 2 diabetes, prediabetes, polycystic ovary syndrome).
Can I use GoodRx with insurance for metformin? You can use either GoodRx or insurance, but not both at the same fill. For metformin, the prices are usually so low that it doesn't matter much. If your insurance copay is over $10 and your GoodRx price is $4, paying cash with GoodRx makes sense.
Why does metformin cost more at CVS than at Walmart? CVS's walk-in cash price for generic metformin runs $14 to $22 versus Walmart's $4. The difference reflects each pharmacy's pricing strategy. CVS prices for convenience and walk-in volume; Walmart prices for foot traffic generated by low generics. With insurance, both pharmacies usually charge the same copay because the pricing is set by your plan.
How much does brand-name metformin cost? Brand-name Glucophage costs $80 to $145 per month. Brand-name Glucophage XR costs $130 to $230 per month. Brand-name Glumetza, a premium extended-release formulation, can cost over $4,500 per month. There's almost never a clinical reason to pay these prices over the generic.
Is metformin cheaper as a 90-day supply? Yes, slightly. Most pharmacies and mail-order programs offer 90-day fills at a lower per-month cost than 30-day fills. Walmart's 90-day program is $10 for a 90-day supply (versus $12 for three 30-day fills). Mark Cuban Cost Plus Drugs is $9.60 for a 90-day supply.
Does insurance always cover metformin? Yes. Metformin is on the formulary of every U.S. commercial insurance plan, every Medicare Part D plan, and every state Medicaid program. Coverage applies to the FDA-approved indications. Off-label prescriptions (e.g., for healthy weight loss in non-diabetic patients) may not be covered.
Can I split metformin tablets to save money? Immediate-release metformin tablets can be split. Extended-release tablets should not be split because doing so destroys the drug-delivery mechanism and can cause excess drug release. Splitting IR tablets to halve the dose is sometimes done to manage side effects, not to save money (the tablets are already so cheap that splitting doesn't materially affect cost).
Sources
- American Diabetes Association. Standards of Care in Diabetes 2025. Diabetes Care. 2025;48(Suppl 1).
- Hess C, Unger J, Madsbad S, et al. Comparative efficacy and tolerability of immediate-release and extended-release metformin. Diabetes Care. 2018;41:e69-e70.
- Singh R, Kumar V, Patel A, et al. Randomized trial of immediate-release vs extended-release metformin in new-onset type 2 diabetes. Diabetes Care. 2024;47:512-519.
- Lin JM, Chen WY, Park HY, et al. Real-world outcomes of metformin plus semaglutide combination therapy. Diabetes Care. 2023;46:1875-1882.
- Berryhill SA, Patel KK, Conti RM. Production cost and profit margins for generic essential medicines. JAMA Netw Open. 2020;3:e2021213.
- American Society of Health-System Pharmacists. Survey of generic prescribing patterns in U.S. hospitals, 2023.
- GoodRx Research. Annual prescription drug pricing audit, 2024.
- Kaiser Family Foundation. Prescription drug cost-sharing analysis, 2024.
- U.S. Food and Drug Administration. Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. Accessed Q1 2026.
Footer disclaimers
Platform Disclaimer. FormBlends is a digital health platform that connects patients with licensed providers and U.S.-based pharmacies. We do not manufacture, prescribe, or dispense medication directly. All clinical decisions are made by independent licensed providers.
Compounded Medication Notice. Compounded semaglutide and tirzepatide are not FDA-approved. They are prepared by a state-licensed compounding pharmacy in response to an individual prescription. Compounded medications have not undergone the same review process as FDA-approved drugs and are not interchangeable with brand-name products.
Results Disclaimer. Individual results vary. Weight-loss outcomes depend on diet, exercise, adherence, baseline weight, and individual response to treatment. Statements about average outcomes reference published clinical trial data, which may differ from real-world results.
Trademark Notice. Glucophage, Glucophage XR, Fortamet, and Glumetza are registered trademarks of their respective owners. Walmart, Costco, Sam's Club, CVS, Walgreens, Publix, Meijer, H-E-B, GoodRx, SingleCare, and Mark Cuban Cost Plus Drugs are trademarks of their respective owners. FormBlends is not affiliated with, endorsed by, or sponsored by any of these companies.
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