Alethro
AlethroDrug indexMetformin
Diabetes

Metformin costs $0–$15/month.

Metformin costs $0–$10/month for most insured patients in 2026, with no prior authorization required and cash prices as low as $4/month at Walmart and Costplus — the most commonly prescribed first-line type 2 diabetes medication.

Estimates only. Verify with your pharmacy and insurer before filling. Not medical, financial, or insurance advice.

Cost calculatorEstimates only · verify before filling
Step 1 of 3Drug

What are you filling?

Nothing stored. Result page is a shareable URL — no signup.
$18
Manufacturer list
No mfr program
$0–$15
Typical with insurance
Tier 1
Most formularies
Where to fill

Metformin prices by source

Manufacturer list (cash, no insurance)
Published list price · 30-day supply
$18
Costplus Drug Company
Mark Cuban's Cost Plus Drugs · cash price
$6
Walmart $4 generic list
Walmart pharmacy · 30-day supply
$4
GoodRx
Coupon-based pricing varies by pharmacy and ZIP
~$6

Sources: manufacturer published pricing · Costplus Drug Co. catalog · Walmart $4 list · GoodRx public pricing.

Commercial insurance

Your cost by plan

Tier from each carrier’s 2026 formulary — source documents linked on each plan card below. Use the calculator above for a personalized estimate based on your deductible state.

Blue Cross Blue Shield Employer PPO
Illinois Blue Choice PPO
Tier 1No PA
$0–$15/mo
See formulary
Blue Cross Blue Shield Employer HMO
Texas Blue Advantage HMO
Tier 1No PA
$0–$15/mo
See formulary
Aetna HDHP / HSA
Choice POS II HSA
Tier 1No PA
$0–$15/mo
See formulary
UnitedHealthcare Employer PPO
Choice Plus PPO
Tier 1No PA
$0–$15/mo
See formulary
Kaiser Permanente Employer HMO
Signature HMO
Tier 1No PA
$0–$15/mo
See formulary
Cigna Employer PPO
Open Access Plus
Tier 1No PA
$0–$15/mo
See formulary
Anthem Marketplace Silver
Silver 4500/40 Marketplace
Tier 1No PA
$0–$15/mo
See formulary
Blue Shield of California Employer HMO
Access+ HMO
Tier 1No PA
$0–$15/mo
See formulary
Anthem BCBS New York Employer HMO
Pathway HMO
Tier 1No PA
$0–$15/mo
Carrier page
Florida Blue Marketplace HMO
myBlue HMO
Tier 1No PA
$0–$15/mo
Carrier page
BCBS Michigan Employer PPO
Community Blue PPO
Tier 1No PA
$0–$15/mo
See formulary
Independence Blue Cross Employer PPO
Personal Choice PPO
Tier 1No PA
$0–$15/mo
See formulary
Humana Employer PPO
ChoiceCare PPO (Commercial)
Tier 1No PA
$0–$15/mo
Carrier page
Ambetter (Centene) Marketplace Silver
Balanced Silver
Tier 1No PA
$0–$15/mo
See formulary
Oscar Health Marketplace Bronze
Bronze Classic
Tier 1No PA
$0–$15/mo
Carrier page
Kaiser Permanente Employer HMO
Mid-Atlantic HMO (MD/VA/DC)
Tier 1No PA
$0–$15/mo
Carrier page
CareFirst BCBS Employer HMO
BlueChoice HMO (DC/MD/VA)
Tier 1No PA
$0–$15/mo
See formulary
FAQ

Metformin cost questions

How much does metformin cost with insurance?
Most commercially insured patients pay $0–$10/month for metformin. As a Tier 1 generic on every plan's formulary, copays are minimal. Some plans even waive the copay entirely for first-line diabetes medications.
What is the cheapest pharmacy for metformin?
Walmart's $4 generic list covers metformin at $4 for a 30-day supply (immediate-release). Costplus Drug Company sells it at similar low prices. Extended-release metformin (Glucophage XR generic) is slightly more expensive but still under $20/month.
Is metformin available as a generic?
Metformin IS the generic name. Brand names like Glucophage are rarely prescribed today since the generic is so cheap. Extended-release versions (Glucophage XR) also have generic equivalents at low cost.
How does metformin compare to newer diabetes drugs?
Metformin remains the first-line treatment for type 2 diabetes per ADA guidelines. Newer drugs like Jardiance, Farxiga (SGLT2), Ozempic, and Trulicity (GLP-1) are typically added when metformin alone isn't sufficient. Costs for newer drugs are dramatically higher ($300–$1,000/month vs $4 for metformin).
Does Medicare cover metformin?
Yes — metformin is on every Medicare Part D plan's formulary at Tier 1 with minimal or zero copays. It's typically one of the cheapest medications a Medicare beneficiary will fill.
What are common metformin side effects?
Most common side effects are gastrointestinal (nausea, diarrhea, stomach upset), typically improving over the first few weeks. Extended-release forms cause fewer GI issues. Rare but serious: lactic acidosis (associated with kidney function decline). Discuss any concerns with your prescriber.
Can I get metformin without insurance?
Yes — at $4/month from Walmart's generic list, Costplus prices, or GoodRx-discounted retail, metformin is affordable without insurance for nearly anyone. It's one of the most accessible prescription medications in the US.
Why is metformin first-line for diabetes?
Metformin has decades of safety data, proven cardiovascular benefits, doesn't cause hypoglycemia or weight gain, and costs almost nothing. It's the only oral diabetes medication with longstanding evidence of reduced mortality, making it the universal starting point per major guidelines.
Data sources

Source URLs for Metformin have not yet been manually verified. Estimates above are modeled from public pricing patterns and manufacturer-published list prices.

  • • Manufacturer published pricing pages
  • • NADAC National Average Drug Acquisition Cost
  • • Carrier-published formulary tiers (where known)
  • • Cost Plus Drugs / mail-order public pricing
  • • FDA Orange Book (generic availability)