500mg · 30-count · Diabetes · Brand: Glucophage XR · Generic available
| Pharmacy | Cash Price | Per-30-Day Equiv. |
|---|---|---|
| Walmart Cheapest | $4.00 | $4.00 |
| Costco | $4.20 | $4.20 |
| Kroger | $5.00 | $5.00 |
| Target | $6.49 | $6.49 |
| Rite Aid | $17.50 | $17.50 |
| CVS | $18.99 | $18.99 |
| Walgreens | $19.50 | $19.50 |
The generic form of Metformin ER (Metformin HCl ER) contains the same active ingredient and is bioequivalent to the brand. Ask your pharmacist to dispense the generic — it works the same way at a fraction of the cost.
Tip: In most states, pharmacists can substitute a generic unless your prescriber writes "dispense as written" (DAW).
Metformin ER is used to manage blood sugar levels in people with type 2 diabetes. It is sold under the brand name Glucophage XR and is available as the generic Metformin HCl ER. A standard supply is 30 500mg.
Pharmacy pricing is not regulated in the United States, so retailers set their own cash prices. Large retailers like Walmart and Costco typically offer lower prices on generics because they use prescriptions as a traffic driver. Chain pharmacies like CVS and Walgreens tend to charge significantly more.
Diabetes medications can vary widely in price. Generic versions are available for most first-line treatments. Walmart's $4 program covers several common diabetes generics.
Metformin ER belongs to a class of medications called biguanides — this is the extended-release form of metformin, designed to be taken less frequently and to reduce the gastrointestinal side effects some patients experience with the immediate-release version. Extended-release and immediate-release metformin are not automatically interchangeable at the pharmacy; if you were prescribed one form, your pharmacist needs a prescription written for that specific form to fill it correctly.
Shop around. The cheapest pharmacy (Walmart at $4.00) charges significantly less than the most expensive option ($19.50). A quick call can save you real money.
Ask for the generic. If your doctor prescribed the brand-name Glucophage XR, ask your pharmacist whether the generic Metformin HCl ER is available. In most states, pharmacists can substitute a generic unless the prescriber writes 'dispense as written.'
Use a discount card. Services like GoodRx, SingleCare, and WellRx can sometimes negotiate prices lower than retail cash. The estimated GoodRx low for Metformin ER is around $3.80.
Because Metformin ER is a generic medication, manufacturer-sponsored copay savings cards — the kind commonly offered for newer, brand-name drugs — generally aren't available for it. Glucophage XR's manufacturer typically doesn't offer a savings card once generic competition exists, though it's worth checking their site directly if your prescriber specifically writes for the brand product. For most patients filling the generic, the discount-card and pharmacy membership options described above are the more realistic way to lower cost.
Coverage depends on your specific plan and formulary. Most diabetes medications are covered under standard health insurance, typically in Tier 1 or Tier 2. If your copay is higher than the cash price above, it may be cheaper to pay out of pocket — ask your pharmacist to compare. Extended-release metformin is widely covered and rarely subject to prior authorization, though some plans place a quantity limit on the higher-strength tablets.
Prices represent estimated retail cash prices for Metformin ER 500mg (30-count) as of 2026. Actual prices may vary. RxCostCheck does not collect or sell your health data. Learn more →
How much does Metformin ER cost without insurance?
Without insurance, Metformin ER 500mg (30-count) ranges from $4.00 at Walmart to $19.50. With a GoodRx discount card, the price can be as low as $3.80.
Where is the cheapest place to fill Metformin ER?
Walmart typically offers the lowest cash price at $4.00 for 30 500mg.
Is there a generic for Metformin ER?
Yes — the generic Metformin HCl ER is available and bioequivalent to Glucophage XR. Ask your pharmacist to dispense the generic to save money.
What if my insurance doesn't cover Metformin ER at all?
Ask your prescriber whether a covered therapeutic alternative in the same drug class exists, or ask your pharmacist about a formulary exception or medical-necessity appeal — some plans will cover an otherwise-excluded drug once that documentation is on file. In the meantime, the cash and discount-card pricing shown above is usually the fastest fallback.
Does a 90-day supply of Metformin ER cost less than three 30-day fills?
Often, yes — many pharmacies and insurance plans price a 90-day fill at a lower effective per-dose cost than separate 30-day fills, and some mail-order pharmacy benefits are built specifically around 90-day supplies. Ask your pharmacist or insurer whether a 90-day option is available for this medication before assuming the count shown above is your only choice.
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