Which is better, semaglutide or retatrutide?
Semaglutide wins because it is the only one of the two that is lawful to prescribe and the only one with outcome data beyond weight: SELECT and SUSTAIN-6 showed fewer cardiovascular events, and its label covers obesity, diabetes, cardiovascular risk, MASH, and kidney disease. Retatrutide's phase 2 weight loss is larger, but the trial was small and short, safety beyond one year is unknown, and it is a WADA section S0 substance. Revisit if phase 3 (TRIUMPH) leads to approval. [1] [2] [4] [7] [8] [9] [11]
How do semaglutide and retatrutide compare?
| Dimension | SemaglutideFavored | Retatrutide |
|---|---|---|
| Mechanism [4] [8] | Selective GLP-1 receptor agonist. | Triple GIP, GLP-1, and glucagon receptor agonist. |
| Weight loss in the pivotal trial [1] [4] | 14.9% vs 2.4% placebo at 68 weeks with 2.4 mg weekly in STEP 1 (1,961 adults). | 24.2% vs 2.1% placebo at 48 weeks with 12 mg weekly in the phase 2 trial (338 adults); 83% lost at least 15%. |
| Note: Not a direct comparison. Trial size, duration, and population differ. | ||
| Cardiovascular outcomes [2] [3] [4] | SELECT: hazard ratio 0.80 for major adverse cardiovascular events in 17,604 adults with obesity and cardiovascular disease. SUSTAIN-6: hazard ratio 0.74 in type 2 diabetes. | No cardiovascular outcomes trial has reported. Heart rate rises more than with GLP-1 only agonists. |
| Type 2 diabetes evidence [3] [5] [6] [8] | Approved (Ozempic, Rybelsus); SUSTAIN program plus cardiovascular and kidney indications. | Phase 2 (281 adults, 36 weeks) and phase 3 TRANSCEND-T2D-1 (537 adults, 40 weeks) show HbA1c and weight reductions; no approval. |
| Regulatory status [8] [9] [10] | FDA approved (Ozempic 2017, Rybelsus 2019, Wegovy 2021). Shortage-based compounding ended in spring 2025. | Not approved anywhere; not compoundable under 503A or 503B; lawful only inside a registered clinical trial. |
| WADA status [11] | Not on the WADA Prohibited List. | Prohibited at all times under section S0 (non-approved substances). |
| Route and dosing [4] [8] | Subcutaneous injection once weekly (Wegovy 0.25 mg escalating to 2.4 mg) or oral tablet once daily (Rybelsus). | Subcutaneous injection once weekly in trials only, escalated to 1, 4, 8, or 12 mg. No approved dose. |
| Side effects [1] [4] [8] | Nausea 44%, diarrhea 32%, vomiting 24%, constipation 24% in STEP 1; boxed thyroid C-cell warning; gallbladder and pancreatitis warnings. | Dose-related gastrointestinal effects partly reduced by a lower starting dose; larger heart rate increase; skin sensitivity; no long-term safety data. |
| Typical cost [8] [9] | Wegovy list price about 1,349 USD per month; manufacturer cash pricing roughly 349 to 499 USD; 0 to 25 USD with commercial coverage and a savings card. | No lawful price; trial participants receive it free. Online listings are unapproved and unverified. |
Evidence grade and regulatory status
Pulled from each peptide’s own record, so it stays in step with the peptide pages.
| Attribute | Semaglutide | Retatrutide |
|---|---|---|
| Class | GLP-1 receptor agonist (31 amino acid analog of human GLP-1, acylated for once weekly dosing) | Investigational triple agonist of the GIP, GLP-1, and glucagon receptors (single acylated peptide, once weekly) |
| What it is | FDA approved GLP-1 agonist with about 15% average weight loss in a 68 week RCT and proven cardiovascular benefit. | Investigational triple agonist, nicknamed reta or GLP-3, with 24.2% weight loss at 48 weeks in phase 2 and 28.3% in a phase 3 topline; not FDA approved. |
| Evidence | Evidence: Human RCT evidence | Evidence: Human RCT evidence |
| FDA status | Regulatory: FDA approved | Regulatory: Not eligible for compounding |
| Compounding | FDA approved products (Ozempic 2017, Rybelsus 2019, Wegovy 2021). FDA removed semaglutide from the drug shortage list on February 21, 2025; compounding by 503A pharmacies had to stop by April 22, 2025 and by 503B outsourcing facilities by May 22, 2025, except for a documented patient specific clinical need. FDA has warned about unapproved compounded and counterfeit GLP-1 products and salt forms (semaglutide sodium, semaglutide acetate) that are not the approved active ingredient. On April 30, 2026 FDA proposed not to include semaglutide on the 503B bulks list; that proposal was not final as of September 2026. Adding a vitamin such as B12 or niacinamide does not by itself make a compounded GLP-1 different from the approved drug. Under FDA's April 1, 2026 policy update, such a combination may be treated as essentially a copy when the strengths are within 10% of approved products and the route is the same, unless a prescriber documents a real difference for the individual patient. A September 2026 FDA warning letter applied this to semaglutide and tirzepatide vitamin combinations, said high production volume suggested the claimed differences were a pretext, and questioned significant-difference statements picked from preset menus on prescribing platforms. | Not FDA approved and not approved by any other regulator as of the last verification date. Because retatrutide is not a component of an approved drug, has no USP monograph, and is not on the 503A bulks list, it cannot lawfully be compounded by 503A pharmacies or 503B outsourcing facilities. FDA has warned that unapproved GLP-1 class products sold online, including investigational molecules, are not evaluated for safety, quality, or dose. Any product sold as retatrutide outside a clinical trial is unlawful for human use. |
| WADA | WADA: Not WADA prohibited | WADA: WADA prohibited |
| Routes | Subcutaneous injection once weekly (Ozempic, Wegovy), Oral tablet once daily (Wegovy tablets, Ozempic tablets, Rybelsus) | Subcutaneous injection once weekly (clinical trials only) |
| Typical cost | Manufacturer list price is 1,349.02 USD per month for Wegovy and 1,027.51 USD for Ozempic (checked 2026-09-22), falling to 675 USD for both on January 1, 2027. Manufacturer self-pay prices run 149 to 499 USD per month by product and dose, with the Wegovy pen at 349 USD. With commercial insurance the manufacturer savings offer can bring a covered prescription to 25 USD per month, and eligible Medicare Part D enrollees pay 50 USD per month for Wegovy under the Medicare GLP-1 Bridge (July 2026 to December 2027). A 2024 study found compounded semaglutide at a median 231 USD for the first month during the shortage; compounding is now limited to patient specific needs. | Not available through licensed channels. Products sold as research chemicals are not lawful for human use and are not verified for identity or purity. |
| Last verified |
Has semaglutide been tested directly against retatrutide?
No published trial has compared semaglutide and retatrutide directly. The dimensions above come from separate studies and labels, and cross-trial comparisons are less reliable than a direct trial.
What do semaglutide and retatrutide cost?
| Dimension | Semaglutide | Retatrutide |
|---|---|---|
| Typical cost | $149 to $1,349 per month | Not available through licensed channels. Products sold as research chemicals are not lawful for human use and are not verified for identity or purity. |
| Price detail | Semaglutide price by channel | Retatrutide price by channel |
Where a price index exists, the range is the cash price per month across branded, compounded, and telehealth channels, without insurance. The cost pages give each channel separately with its sources. Otherwise the typical cost from the peptide record is shown. Legal access depends on your state: see peptide legality by state.
Frequently asked questions
Is retatrutide stronger than semaglutide for weight loss?
The trial numbers say yes: 24.2% at 48 weeks for retatrutide 12 mg versus 14.9% at 68 weeks for semaglutide 2.4 mg. But those come from a 338 person phase 2 trial and a 1,961 person phase 3 trial that were never compared directly. Phase 3 retatrutide results are needed before the gap can be stated with confidence. [1] [4]
Can I be prescribed retatrutide?
No. It is investigational, not approved by FDA or any other regulator, and cannot be compounded because it is not a component of an approved drug and is not on any bulks list. Semaglutide is available by prescription as Ozempic, Wegovy, or Rybelsus. [8] [9] [10]
Which is safer?
Semaglutide has the safety record: an approved label, trials in tens of thousands of people, and cardiovascular outcomes trials showing benefit. Retatrutide's safety is known only from about a year of data in a few hundred people, and its glucagon activity raises heart rate more than semaglutide does. [2] [4] [8]
Is retatrutide banned in sport?
Yes. WADA section S0 prohibits any substance with no current approval from a government health authority, which covers retatrutide at all times. Semaglutide is not prohibited. [11]
Will retatrutide replace semaglutide?
Unknown. Retatrutide's phase 3 program (TRIUMPH) covers obesity, sleep apnea, and knee osteoarthritis, and it will need FDA review before any comparison of approved products is possible. Semaglutide's advantages today are its cardiovascular, MASH, and kidney indications and its oral form. [7] [8]
Conditions studied
From the blog
- Retatrutide before and after: weight loss by dose and week in the trials
What retatrutide trials measured: 24.2% mean weight loss at 48 weeks in phase 2, up to 28.3% at 80 weeks in phase 3, and what happened to fat, waist size, and blood sugar.
- Retatrutide: where the phase 3 program stands
Five phase 3 readouts, one peer-reviewed paper, and no approval yet. What the retatrutide trials have shown, what is still pending, and why no one can lawfully sell it today.
Sources
Numbered citations above point to these primary sources. PubMed entries link to the indexed abstract.
- [1]Wilding JPH et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med 2021 (STEP 1)PubMed 33567185, 2021
- [2]Lincoff AM et al. Semaglutide and cardiovascular outcomes in obesity without diabetes. N Engl J Med 2023 (SELECT)PubMed 37952131, 2023
- [3]Marso SP et al. Semaglutide and cardiovascular outcomes in patients with type 2 diabetes. N Engl J Med 2016 (SUSTAIN-6)PubMed 27633186, 2016
- [4]Jastreboff AM et al. Triple-hormone-receptor agonist retatrutide for obesity: a phase 2 trial. N Engl J Med 2023PubMed 37366315, 2023
- [5]Rosenstock J et al. Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a phase 2 trial. Lancet 2023PubMed 37385280, 2023
- [6]Efficacy and safety of retatrutide in people with type 2 diabetes (TRANSCEND-T2D-1): a phase 3 trial. Lancet 2026PubMed 42250575, 2026
- [7]Retatrutide for the treatment of obesity, obstructive sleep apnea and knee osteoarthritis: rationale and design of the TRIUMPH registrational clinical trials. Diabetes Obes Metab 2026PubMed 41090431, 2026
- [8]FDA prescribing information for Wegovy (semaglutide) injection, via DailyMedFDA, 2025
- [9]FDA: concerns with unapproved GLP-1 drugs used for weight lossFDA, 2025
- [10]FDA: Bulk drug substances used in compounding under section 503A of the FD&C ActFDA, 2026
- [11]WADA Prohibited List, section S0 non-approved substancesWADA, 2026
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