Semaglutide vs Tirzepatide vs Retatrutide: Cost Per Month (Plain-English 2026 Guide)

Which is cheaper per month — semaglutide, tirzepatide, or retatrutide? Compare cost per month at brand pharmacies, compounded telehealth, and research peptide vendors with live WPA dosing data.

The 3 Drugs in Plain Words

Semaglutide is a single GLP-1 receptor agonist sold as Ozempic (diabetes) and Wegovy (weight loss). Tirzepatide is a dual GLP-1 + GIP receptor agonist sold as Mounjaro and Zepbound. Retatrutide is a triple agonist (GLP-1 + GIP + glucagon receptor) still in clinical trials with no FDA-approved brand name yet.

The Big Price Picture (Monthly Cost Ladder)

  • Semaglutide (GLP-1) — at the WPA community most common dose of 0.25 mg / week (369 calculations): brand pharmacy $950–$1,350 / month; compounded $165–$349 / month; research peptide $35–$90 / month.
  • Tirzepatide (GLP-1 + GIP) — at the WPA community most common dose of 2.5 mg / week (1,887 calculations): brand pharmacy $1,000–$1,450 / month; compounded $199–$449 / month; research peptide $50–$130 / month.
  • Retatrutide (GLP-1 + GIP + Glucagon (triple agonist)) — at the WPA community most common dose of 2 mg / week (1,853 calculations): brand pharmacy Not available; compounded Not available; research peptide $80–$220 / month.

Brand pharmacy = US cash list price. Compounded = telehealth subscription pricing. Research = computed from current WPA-tracked vendor median price-per-mg multiplied by monthly mg at the WPA community most common dose.

Brand Pharmacy Cost

At a US pharmacy with no insurance, the brand-name pens are the most expensive way to get any of these drugs. Ozempic runs about $998 per month, Wegovy about $1,349, Mounjaro about $1,069, and Zepbound about $1,086 at cash list price. Retatrutide has no brand-name pen because it has not been FDA-approved.

Compounded Telehealth Cost

Compounded means a US pharmacy mixes the active ingredient itself rather than dispensing the brand pen. Compounded semaglutide usually runs $165–$349 per month and compounded tirzepatide $199–$449 per month, depending on dose tier and provider. Retatrutide is not legally compounded for human use.

Research-Peptide Cost

The research-peptide market sells these compounds as freeze-dried powder in glass vials, sold for laboratory research only. Per milligram this is by far the cheapest channel, which is why monthly cost can be 10x to 30x lower than brand pharmacy at the same milligram dose.

The Dose Question: Real-World vs Clinical-Trial Dose

  • Semaglutide: WPA community real dose 0.25 mg / week vs STEP-1 (NEJM 2021) maintenance dose 2.4 mg / week (real-world researchers start at roughly 10% of the trial dose).
  • Tirzepatide: WPA community real dose 2.5 mg / week vs SURMOUNT-1 (NEJM 2022) maintenance dose 15 mg / week (real-world researchers start at roughly 17% of the trial dose).
  • Retatrutide: WPA community real dose 2 mg / week vs Phase-2 obesity trial (NEJM 2023) maintenance dose 12 mg / week (real-world researchers start at roughly 17% of the trial dose).

How Often & For How Long

All three compounds are once-weekly in the published label, and the WPA community largely follows that — about 84% of cadence entries across the three compounds are once-weekly. A minority split the same total weekly milligrams across 2–3 smaller injections.

  • Semaglutide — 88% weekly, 11% split into more frequent injections (n=363). Of the 11% who split, the most common pattern is Daily (7x/week) at 7%.
  • Tirzepatide — 91% weekly, 9% split into more frequent injections (n=1,244). Of the 9% who split, the most common pattern is Daily (7x/week) at 6%.
  • Retatrutide — 82% weekly, 17% split into more frequent injections (n=4,439). Of the 17% who split, the most common pattern is 2x/week at 8%.

Why split? Splitting the same weekly milligrams across two or three smaller injections lowers the peak concentration and raises the trough. Some users hypothesise that the lower peak reduces peak-driven side effects (nausea, GI distress) and that holding total weekly exposure constant while flattening the curve translates to more consistent effect. This is not established science — ask a clinician before changing your protocol.

Reconstitute one vial with bacteriostatic water using the WPA peptide calculator, then pick a fixed day each week or a 2–3 day split schedule, and track how many weeks one vial lasts. A 10 mg vial of semaglutide at 0.25 mg/week lasts about 40 weeks; a 20 mg vial of retatrutide at 2 mg/week lasts about 10 weeks. Cost per month is just the vial price ÷ months covered.

Frequently Asked Questions

How much does semaglutide cost per month?

Semaglutide cost per month ranges from about $35 on the research-peptide side to about $1,350 at a US brand pharmacy. Brand pens (Ozempic or Wegovy) cost about $950 to $1,350 a month at a US pharmacy. Compounded shots from a telehealth clinic cost about $165 to $349 a month. Research kits from a peptide shop cost about $4 to $41 a month at the most common starter dose (0.25 mg a week), based on live World Peptide Association vendor pricing.

How much does tirzepatide cost per month?

Tirzepatide cost per month ranges from about $50 on the research-peptide side to about $1,450 at a US brand pharmacy. Brand pens (Mounjaro or Zepbound) cost about $1,000 to $1,450 a month. Compounded shots cost about $199 to $449 a month. Research kits cost about $17 to $155 a month at the most common starter dose (2.5 mg a week), based on live World Peptide Association vendor pricing.

How much does retatrutide cost per month?

Retatrutide cost per month is roughly $80 to $220 on the research-peptide side and not available through any other US channel. There is no brand pen yet — it is still being tested in clinical trials. Compounding it is not legal in the US. Research kits cost about $22 to $138 a month at the most common starter dose (2 mg a week), based on live World Peptide Association vendor pricing.

Which is cheaper, semaglutide or tirzepatide?

Which is cheaper, semaglutide or tirzepatide, depends on the channel — but in every channel semaglutide comes out cheaper per month at the most common starter dose. At a US brand pharmacy, semaglutide (Ozempic/Wegovy) runs roughly $70 to $100 less per month than tirzepatide (Mounjaro/Zepbound). At a compounded telehealth clinic, semaglutide is about $30 to $100 cheaper per month than tirzepatide on the same dose tier. On the research-peptide side, semaglutide is about $4 to $41 a month versus about $17 to $155 a month for tirzepatide. The gap closes (and sometimes flips) once you titrate up — tirzepatide milligrams go further per kilogram of body-weight effect in trials.

Why is tirzepatide more expensive than semaglutide?

Tirzepatide is more expensive than semaglutide because it is a newer molecule, it is dual-agonist (it activates two receptors instead of one), and Eli Lilly has not faced generic or post-shortage compounding pressure at the same scale as semaglutide. Brand-pharmacy list prices for Mounjaro and Zepbound run roughly $70 to $100 more per month than Ozempic. Tirzepatide is also dosed in larger milligram amounts than semaglutide (2.5 mg/week to start vs 0.25 mg/week), so on a per-milligram basis a research kit costs more to fill a month.

What is the price difference between semaglutide and tirzepatide per month?

The price difference between semaglutide and tirzepatide per month at the US brand pharmacy is roughly $70 to $100 — Wegovy is about $1,349/month while Zepbound is about $1,086/month for the lowest tier, but tirzepatide pens generally trend higher than semaglutide pens at matched dose tiers. On the compounded side, tirzepatide runs about $30 to $100 more per month than semaglutide. On the research-peptide side at the WPA most-common dose, semaglutide is about $4 to $41 a month and tirzepatide is about $17 to $155 a month.

Is retatrutide more expensive than tirzepatide?

Retatrutide is more expensive than tirzepatide on the research-peptide side at the most common starter dose: retatrutide is about $22 to $138 a month versus about $17 to $155 a month for tirzepatide. That is because retatrutide is the newest of the three, vial pricing per milligram is higher, and the typical weekly milligram amount is also higher. Retatrutide has no brand pharmacy or legal compounded option, so the brand-vs-brand comparison does not exist.

Tirzepatide vs Ozempic cost — what's the actual difference?

Tirzepatide vs Ozempic cost at US brand pharmacies: Mounjaro (tirzepatide for diabetes) is about $1,069/month cash list, while Ozempic (semaglutide for diabetes) is about $998/month — roughly $70/month more for tirzepatide. The weight-loss brands are further apart on absolute dollars: Wegovy (semaglutide) is about $1,349/month and Zepbound (tirzepatide) is about $1,086/month, but tirzepatide tends to scale higher than semaglutide as you titrate up the dose ladder. Insurance, manufacturer savings cards, and direct-from-Lilly vial programs can shift either number substantially.

What is the difference between semaglutide, tirzepatide, and retatrutide?

Semaglutide turns on one hunger switch in the body (GLP-1). Tirzepatide turns on two (GLP-1 + GIP). Retatrutide turns on three (GLP-1 + GIP + glucagon). More switches often means more weight loss in trials. It can also mean a higher price.

Why is the WPA community dose so much lower than the clinical-trial dose?

Trials push the dose up to the highest amount people can handle. That helps the trial measure the biggest effect. Most people in the real world start much lower and only go up if they need to. A lower dose also costs less each month. That is why our cost numbers use the most common dose, not the trial dose.

Is compounded semaglutide or tirzepatide legal?

Yes, US pharmacies sell compounded shots through telehealth clinics. The rules can change when the FDA changes its drug shortage list. Check the FDA page and your state pharmacy board before you sign up. Retatrutide cannot be compounded.

Can I just compare the price tags directly?

No. Each option comes in a different size. To be fair, you need to compare cost per month at the same dose. The live cards in section 10 do that math for you using today's vendor prices.

Sources & Citations

  1. Novo Nordisk — Ozempic US list price page — retrieved 2026-05-09
  2. Novo Nordisk — Wegovy US list price page — retrieved 2026-05-09
  3. Eli Lilly — Mounjaro list price page — retrieved 2026-05-09
  4. Eli Lilly — Zepbound list price page — retrieved 2026-05-09
  5. Wilding et al., Once-Weekly Semaglutide for Weight Loss (STEP-1), NEJM 2021 — retrieved 2026-05-09
  6. Jastreboff et al., Tirzepatide for Obesity (SURMOUNT-1), NEJM 2022 — retrieved 2026-05-09
  7. Jastreboff et al., Triple-Hormone-Receptor Agonist Retatrutide for Obesity, NEJM 2023 — retrieved 2026-05-09
  8. FDA — Compounded GLP-1 drugs status page — retrieved 2026-05-09
  9. GoodRx — Ozempic average retail / cash price — retrieved 2026-05-09
  10. GoodRx — Mounjaro average retail / cash price — retrieved 2026-05-09
  11. GoodRx — Zepbound average retail / cash price — retrieved 2026-05-09
  12. LillyDirect — direct-from-manufacturer Zepbound vial pricing — retrieved 2026-05-09
  13. Noom Med — compounded GLP-1 telehealth pricing — retrieved 2026-05-09
  14. Henry Meds — compounded semaglutide / tirzepatide telehealth pricing — retrieved 2026-05-09
  15. Mochi Health — compounded GLP-1 telehealth pricing — retrieved 2026-05-09
  16. Ro — Zepbound and compounded GLP-1 telehealth pricing — retrieved 2026-05-09
  17. WPA live community dose, vial, BAC, and cadence statistics — refreshed every page load via /api/learn/sema-tirz-reta-cost/live-stats — retrieved live