Retatrutide vs mazdutide: evidence, cost, and legality

Which is better, retatrutide or mazdutide?

On efficacy, retatrutide's phase 3 weight loss is roughly double mazdutide's at the doses tested so far, though no trial compares them and TRIUMPH-1 is reported only in a press release. On regulatory standing, mazdutide is ahead because China's regulator has approved it. For a US reader both are trial-only drugs, so the comparison matters mostly for following the pipeline. [1] [2] [3] [4] [5]

How do retatrutide and mazdutide compare?

Retatrutide and Mazdutide compared by dimension
Dimension	Retatrutide	Mazdutide
Mechanism [2] [6]	Triple agonist of the GIP, GLP-1, and glucagon receptors.	Dual agonist of the GLP-1 and glucagon receptors (oxyntomodulin analog).
Note: Both use glucagon receptor activity to raise energy expenditure; retatrutide adds GIP receptor activity.
Best weight loss evidence [1] [2] [3]	TRIUMPH-1 (2,339 adults, 80 weeks): 19.0%, 25.9%, and 28.3% at 4, 9, and 12 mg versus 2.2% on placebo (efficacy estimand), per manufacturer topline results.	GLORY-1 (610 Chinese adults, 48 weeks): 11.0% and 14.0% at 4 and 6 mg versus 0.3% gain on placebo. US phase 2 (179 adults, 32 weeks): up to 18.1% at 16 mg.
Type 2 diabetes evidence [7] [8] [9]	TRANSCEND-T2D-1 phase 3 (537 adults, 40 weeks) showed significant HbA1c and weight improvement; TRIUMPH-2 reported up to 20.8% weight loss in obesity with type 2 diabetes (topline).	DREAMS-2 phase 3 (731 adults, 28 weeks): HbA1c 0.24 to 0.30 points and weight 3.8% to 5.8% lower than dulaglutide 1.5 mg.
Tolerability [1] [2] [10]	TRIUMPH-1: nausea 28.6% to 42.4% versus 14.8% on placebo; discontinuation for adverse events 11.3% at 12 mg versus 4.9%.	GLORY-1: discontinuation for adverse events 1.5% or less; the diabetes phase 2 trial reported diarrhea in 36% and nausea in 23%.
Regulatory status [4] [5] [11]	Investigational; not approved by FDA or any other regulator, not eligible for compounding.	Approved in China (weight management June 2025, type 2 diabetes September 2025). Not FDA approved and not eligible for US compounding.
WADA status [4] [12]	Prohibited under section S0 (non-approved substances).	Not named on the list; with approval in China, section S0 may not apply. Athletes should confirm with their anti-doping organization.
Trial doses [1] [2] [3]	Once weekly 4, 9, or 12 mg in phase 3.	Once weekly 4 or 6 mg in GLORY-1; 3 to 16 mg in the US phase 2 trial.

Evidence grade and regulatory status

Pulled from each peptide’s own record, so it stays in step with the peptide pages.

Retatrutide and Mazdutide: grade, status, and cost
Attribute	Retatrutide	Mazdutide
Class	Investigational triple agonist of the GIP, GLP-1, and glucagon receptors (single acylated peptide, once weekly)	Dual agonist of the GLP-1 and glucagon receptors (oxyntomodulin analog, acylated, once weekly)
What it is	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.	GLP-1/glucagon dual agonist with 14% weight loss at 48 weeks in a Chinese phase 3 trial and 18% at 16 mg in a US phase 2; not FDA approved.
Evidence	Evidence: Human RCT evidence	Evidence: Human RCT evidence
FDA status	Regulatory: Not eligible for compounding	Regulatory: Not eligible for compounding
Compounding	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.	Not FDA approved as of the last verification date. Because mazdutide is not a component of an FDA approved drug, has no USP monograph, and is not on the 503A bulks list, it cannot lawfully be compounded or dispensed in the United States, and any product sold as mazdutide in the US is an unapproved drug. Its development and registration have centered on China, where the national drug regulator approved it for chronic weight management in adults (June 2025) and for type 2 diabetes (September 2025); those approvals do not make it legal to sell or compound in the US.
WADA	WADA: WADA prohibited	WADA: WADA status unclear
Routes	Subcutaneous injection once weekly (clinical trials only)	Subcutaneous injection once weekly
Typical cost	Not available through licensed channels. Products sold as research chemicals are not lawful for human use and are not verified for identity or purity.	Not available through licensed channels in the United States. Products sold as research chemicals are not lawful for human use and are not verified for identity or purity.
Last verified	Sep 23, 2026	Sep 27, 2026

Has retatrutide been tested directly against mazdutide?

No published trial has compared retatrutide and mazdutide directly. The dimensions above come from separate studies and labels, and cross-trial comparisons are less reliable than a direct trial.

What do retatrutide and mazdutide cost?

Typical cost of Retatrutide and Mazdutide
Dimension	Retatrutide	Mazdutide
Typical cost	Not available through licensed channels. Products sold as research chemicals are not lawful for human use and are not verified for identity or purity.	Not available through licensed channels in the United States. Products sold as research chemicals are not lawful for human use and are not verified for identity or purity.
Price detail	Retatrutide price by channel	Price index in progress

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

Which causes more weight loss, retatrutide or mazdutide?

Retatrutide in the trials reported so far: 28.3% at 12 mg over 80 weeks in TRIUMPH-1 versus 14.0% at 6 mg over 48 weeks for mazdutide in GLORY-1. There is no head-to-head trial, and higher mazdutide doses (up to 16 mg) are still in development. [1] [2] [3]

Is either one approved?

Mazdutide is approved in China for chronic weight management and type 2 diabetes. Retatrutide is not approved anywhere. Neither is FDA approved. [4] [5] [11]

Can I buy retatrutide or mazdutide legally in the US?

No. Neither is FDA approved or on the 503A bulks list, so neither can be lawfully compounded or sold for human use. Products labeled research use only are not verified for identity or purity. [5] [13]

Are they allowed in tested sport?

Retatrutide is prohibited under WADA section S0. Mazdutide's status is less clear because it is approved in China; athletes should ask their anti-doping organization before use. [12]

Conditions studied

Sources

Numbered citations above point to these primary sources. PubMed entries link to the indexed abstract.

Cite this page

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APA style: PeptideAgent. (2026, September 22). Retatrutide vs mazdutide: evidence, cost, and legality. https://peptideagent.ai/compare/retatrutide-vs-mazdutide
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Retatrutide vs mazdutide

The short answer