FDA's records date metformin's first US approval, as Glucophage, to March 1995 [4], and the authors of its landmark trial called it a likely first-line choice for overweight people with type 2 diabetes [5]. Ozempic arrived in 2017 and became famous for something its label doesn't cover: weight loss. Because both show up in the same conversations, people ask whether metformin is a cheaper version of Ozempic. It isn't. They come from different drug classes and work in different places in the body.
Different classes of drug, working in different places
Metformin is a biguanide. Its label says it lowers blood sugar three ways: it decreases the liver's glucose production, decreases the gut's absorption of glucose and improves insulin sensitivity. It doesn't increase insulin secretion [1].
Ozempic contains semaglutide, which copies a gut hormone called GLP-1. Its label says it raises insulin and lowers glucagon when blood sugar is high, with a minor delay in stomach emptying after meals [2]. The same molecule in Wegovy acts on brain areas that regulate appetite, which is why it lowers weight [3].
| Metformin | Ozempic | |
|---|---|---|
| Drug class | Biguanide | GLP-1 receptor agonist (semaglutide) |
| How it lowers blood sugar | Less glucose from the liver, less absorbed from the gut, better insulin sensitivity | More insulin and less glucagon when glucose is high; slightly slower stomach emptying |
| Form | Tablet, immediate- or extended-release | Weekly injection pen |
| Approved for | Blood-sugar control in type 2 diabetes: adults, and children 10+ (immediate-release) | Blood-sugar control in adults with type 2 diabetes |
| Outcome labels | None | Lower heart-attack, stroke and heart-death risk with heart disease; lower kidney-failure and heart-death risk with chronic kidney disease |
| Weight | Not labeled; little change in its label trial | Not labeled for weight; weight usually falls |
| Boxed warning | Lactic acidosis | Thyroid C-cell tumors seen in rodents |
| Who shouldn't take it (examples) | Severe kidney impairment (eGFR below 30), metabolic acidosis | Personal or family history of medullary thyroid cancer or MEN 2 |
| Generic? | Yes | No, brand only |
From the current DailyMed labels: a representative generic metformin label (version 8, September 2026) and Ozempic injection (version 20, June 2026).
Both treat type 2 diabetes; only Ozempic has heart and kidney labels
Both labels cover improving blood-sugar control alongside diet and exercise in type 2 diabetes. Metformin's immediate-release tablets are also approved for children 10 and older [1]. Ozempic is for adults only.
Ozempic's label goes further. It's approved to reduce the risk of heart attack, stroke and cardiovascular death in adults with type 2 diabetes and established heart disease. Since January 2025 it's also approved to reduce the risk of kidney decline, kidney failure and cardiovascular death in adults with type 2 diabetes and chronic kidney disease [2]. Metformin's label has no outcome indication.
What the outcome trials showed
No outcome label doesn't mean no outcome evidence. Metformin's main outcome trial is older and smaller than Ozempic's, and the two were tested in different groups.
| Trial | Who was in it | What it found |
|---|---|---|
| UKPDS 34 (metformin), 1998 | 753 overweight adults with newly diagnosed type 2 diabetes, followed a median 10.7 years | Compared with a mainly diet-based policy: any diabetes endpoint down 32%, diabetes deaths down 42%, deaths from any cause down 36% [5] |
| DPP (metformin), 2002 | 3,234 adults with prediabetes, no diabetes | Metformin cut new diabetes by 31% against placebo; a lifestyle program cut it by 58% [6] |
| SUSTAIN-6 (Ozempic), 2016 | 3,297 adults with type 2 diabetes at high heart risk, 104 weeks | Heart attack, stroke or heart death: 6.6% vs 8.9% on placebo (hazard ratio 0.74) [7] |
| FLOW (Ozempic), 2024 | 3,533 adults with type 2 diabetes and chronic kidney disease, median 3.4 years | Major kidney events or kidney or heart death 24% lower than placebo (hazard ratio 0.76) [8] |
UKPDS 34 also ran a smaller trial in which adding metformin to sulfonylurea treatment was linked to more diabetes-related deaths; the authors' wider analysis did not confirm that risk. Novo Nordisk funded SUSTAIN-6 and FLOW.
The comparison groups differ, so the numbers don't rank the drugs. UKPDS 34 compared metformin with a mostly diet-only policy decades ago. SUSTAIN-6 and FLOW added semaglutide to people's existing care, which often included metformin.
Weight: neither is a weight-loss drug on its label
Metformin is often described as weight-friendly. The trial printed on its label is more modest: across 29 weeks, the metformin group's average weight fell 1.4 pounds, slightly less than placebo's 2.4 [1]. In UKPDS 34, metformin was linked with less weight gain than insulin or sulfonylureas, which is a different claim from weight loss [5].
Ozempic does lower weight; its label says semaglutide reduces body weight [2]. But it isn't approved for that. The semaglutide product labeled for weight management is Wegovy, which goes to higher doses. If weight is the main goal, that's the comparison to read, along with Ozempic vs Wegovy.
Metformin also gets attention as a possible longevity drug. That use is off-label, and randomized evidence that it slows aging in healthy people doesn't exist yet. The evidence is in metformin and longevity.
Side effects and warnings
- Both: stomach effects are the most common, including diarrhea and nausea [1] [2].
- Metformin: a boxed warning for lactic acidosis, rare but sometimes fatal, with higher risk in kidney impairment and at 65 and older. It can also lower vitamin B12, and the label calls for periodic checks [1].
- Ozempic: a boxed warning for thyroid C-cell tumors seen in rodents, plus warnings that include pancreatitis and diabetic eye complications. SUSTAIN-6 found more retinopathy complications on semaglutide (hazard ratio 1.76) [2] [7].
- Low blood sugar: both labels flag a higher risk when the drug is combined with insulin or a sulfonylurea [1] [2].
If you're on metformin and feeling worn out, see does metformin make you tired.
Yes, they're often taken together
Ozempic's label says it has been studied alone and in combination with metformin, metformin plus a sulfonylurea, and other diabetes medicines [2]. In one of those trials, 94% of participants were taking metformin. SURPASS-2, the trial that set Mounjaro's tirzepatide against Ozempic's semaglutide, enrolled only people already on a stable metformin dose [9] [10].
So the real choice is rarely metformin or Ozempic. It's whether to add Ozempic, or another drug, to metformin when blood sugar stays high, or when heart or kidney protection matters. That's a decision for your prescriber, who weighs your A1C, kidney function, heart history and cost. For the comparison with Lilly's diabetes drug, see Ozempic vs Mounjaro.
Cost: metformin costs far less
Generic metformin tablets are inexpensive. When you get them through a telehealth program, most of what you pay covers the visit and the program, not the pill. Ozempic is brand-only, so its price is set by Novo Nordisk.
| Option | Monthly cost | What it covers |
|---|---|---|
| Metformin via Found | $161.86/mo | Prescription plus program |
| Ozempic pen, NovoCare self-pay | $199 for the first 2 fills, then $349 (0.25 to 1 mg) or $499 (2 mg) | Medication only; starter price for new patients through December 31, 2026 |
| Ozempic tablets, NovoCare self-pay | Starting at $149 (1.5 mg) | Medication only |
Metformin prices from each provider's own site; telehealth metformin range $25–$162. Ozempic prices from NovoCare, which says pricing will be updated after December 31, 2026.
Also offered by (no standing monthly price published): Metformin via HealthRx.
On NovoCare's regular pen price, a year of Ozempic at up to 1 mg comes to $4,188 by our arithmetic [11]. Insurance usually covers both drugs for type 2 diabetes, often at very different copays. Every Ozempic option is in Ozempic cost without insurance, getting metformin online is covered in metformin prescriptions online, and the monthly cost tool adds up program fees.