Retatrutide in Mexico 2026: scientific guide to the triple GLP-1/GIP/GCG agonist

EXOMA Scientific Team · Publicado el 24 de mayo de 2026 · Actualizado el 18 de septiembre de 2026

Comprehensive evidence-based guide to Retatrutide (LY-3437943): triple mechanism, phase 2 clinical trials (NEJM 2023), comparison vs Tirzepatide and Semaglutide, typical research doses, reconstitution and availability in Mexico with

TL;DR

Retatrutide (Retatrutide, LY-3437943) is a synthetic polypeptide in clinical research developed by Eli Lilly that acts as simultaneous triple agonist of the GLP-1, GIP, and glucagon (GCG) receptors. In the phase 2 trial published in NEJM 2023 (Jastreboff et al., doi:10.1056/NEJMoa2301972) it reported a mean weight reduction of up to 24.2% of baseline body weight at 48 weeks with the 12 mg weekly dose, surpassing the published results of Tirzepatide and Semaglutide in comparable studies. EXOMA Peptides offers 8 presentations (5–60 mg) with HPLC purity and COA per batch, exclusively for research use.

Index

1. ¿Qué es Retatrutida?
2. Mecanismo molecular: el agonismo triple
3. Evidencia clínica publicada (fase 1 y fase 2)
4. Retatrutida vs Tirzepatide vs Semaglutida
5. Typical research doses and titration
6. Reconstitution and storage
7. Presentaciones disponibles in Mexico
8. Marco regulatorio y advertencia
9. FAQ
10. References

1. What is Retatrutide?

Retatrutide is the proposed international nonproprietary name (INN) for the experimental compound LY-3437943 from Eli Lilly. Structurally it is a modified 39-amino-acid polypeptide derived from the glucagon sequence, with a fatty-acid side chain (C20-diacid) attached to lysine 17 via a γGlu-2xOEG spacer. This lipid modification allows binding to serum albumin, which extends the plasma half-life to approximately 6 days, supporting weekly administration.

Retatrutide's clinical program covers multiple research indications: obesity (TRIUMPH-1, NCT05929066), type 2 diabetes (NCT04881760), cardiovascular disease (TRIUMPH-3, NCT05882045) and chronic kidney disease.

2. Molecular mechanism: the triple agonism

The most significant difference of Retatrutide compared to other incretins is the simultaneous activation of three G protein-coupled receptors:

• GLP-1R (Glucagon-Like Peptide-1 Receptor): it mediates central satiety, delayed gastric emptying and potentiation of glucose-dependent insulin secretion.
• GIP-R (Glucose-dependent Insulinotropic Polypeptide Receptor): contributes to the postprandial insulinotropic response and modulates adipocyte sensitivity to insulin.
• GCG-R (Glucagon Receptor): it increases basal energy expenditure, promotes hepatic lipolysis and increases fatty acid oxidation.

The addition of GCG agonism —absent in Tirzepatide and Semaglutide— is the molecular basis of the increased weight-loss efficacy observed in clinical trials. The functional activity ratio reported for LY-3437943 is approximately 1 (GCG): 1 (GIP): 5 (GLP-1).

3. Published clinical evidence

Phase 1 (NCT04143802)

The first-in-human trial demonstrated a pharmacokinetic profile compatible with weekly dosing, with t½ ≈ 6 days and dose-proportional exposure. No serious adverse events attributable to the drug.

Phase 2 — Obesity (NCT04881760)

Main reference: Jastreboff AM, Kaplan LM, Frías JP, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. N Engl J Med. 2023;389(6):514-526. doi:10.1056/NEJMoa2301972

• N = 338 adults with BMI ≥30 kg/m² (or ≥27 with comorbidity)
• Arms: placebo, 1 mg, 4 mg (with slow or fast titration), 8 mg and 12 mg weekly
• Duration: 48 weeks
• Primary outcome: mean weight reduction at 48 weeks: −24.2% in the 12 mg arm (vs −2.1% in placebo)
• >90% of participants in the 12 mg arm achieved ≥15% weight reduction
• >50% achieved ≥25% weight reduction

Phase 2 — Type 2 diabetes (NCT04867785)

Reference: Rosenstock J, Frias J, Jastreboff AM, et al. Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes. Lancet. 2023;402(10401):529-544. doi:10.1016/S0140-6736(23)01053-X

HbA1c reduction of up to −2.16% absolute at 36 weeks with the 12 mg dose, combined with weight reduction of up to −16.94%.

Other studies

• TRIUMPH-1 (NCT05929066): phase 3 in obesity, ongoing
• TRIUMPH-3 (NCT05882045): Phase 3 in cardiovascular disease, ongoing
• TRIUMPH-OUTCOMES (NCT05882045): long-term cardiovascular evaluation

4. Retatrutide vs Tirzepatide vs Semaglutide

The incremental contribution of GCG agonism is the differentiating factor and the source of the increase in weight efficacy. The activation of GCG increases basal energy expenditure, which allows a negative energy balance without an additive reduction of appetite.

5. Typical doses in research and titration

In the phase 2 trials, the titration protocols sought to mitigate gastrointestinal events:

• Slow titration: 0.5 → 1 → 2 → 4 → 8 → 12 mg, escalating every 4 weeks
• Rapid titration: 2 → 4 → 8 → 12 mg every 2 weeks

In in vitro and preclinical research models, the dose is adjusted according to the experimental system. Any reference is exclusively bibliographic, from the published clinical trials.

6. Reconstitution and storage

Standard reconstitution procedure (research use):

1. Disinfect the stopper of the lyophilized vial and of the vial of bacteriostatic water con alcohol isopropílico
2. Aspirar el volumen calculado de agua bacteriostática (BAC) con jeringa de insulina estéril (usa la calculator)
3. Inject slowly, resting the needle against the inner wall of the vial
4. Rotar suavemente hasta solución transparente — never shake
5. Almacenar refrigerado (2–8 °C) protegido de la luz

The lyophilized vial is stored refrigerated until the retest date indicated on the COA. Avoid freeze-thaw cycles.

7. Presentations available in Mexico

EXOMA Peptides offers 8 presentations of Retatrutide with HPLC-verified purity and COA per batch issued by Chromasys:

• Retatrutide 5 mg, 10 mg, 15 mg, 20 mg, 30 mg, 40 mg, 50 mg, 60 mg

Envío 1-4 días hábiles según zona a toda la República Mexicana. Costo fijo $200 MXN; gratuito en pedidos desde $2,000 MXN. Consulta el Retatrutide Hub for updated prices and availability by batch.

8. Regulatory framework and warning

Retatrutide (LY-3437943) is a molecule in phase 2/3 clinical investigation. All material marketed by EXOMA Peptides is exclusively for research use in vitro or in preclinical models.

9. Frequently asked questions

Check the validated FAQs on each Retatrutide presentation in the hub page.

10. Selected references

1. Jastreboff AM et al. N Engl J Med. 2023;389(6):514-526. doi:10.1056/NEJMoa2301972
2. Rosenstock J et al. Lancet. 2023;402(10401):529-544. doi:10.1016/S0140-6736(23)01053-X
3. Coskun T et al. Cell Metab. 2018;28(4):615-628. doi:10.1016/j.cmet.2018.07.010
4. Frías JP et al. N Engl J Med. 2021;385(6):503-515 (SURPASS-2). doi:10.1056/NEJMoa2107519
5. Wilding JPH et al. N Engl J Med. 2021;384(11):989-1002 (STEP-1). doi:10.1056/NEJMoa2032183
6. Jastreboff AM et al. N Engl J Med. 2022;387(3):205-216 (SURMOUNT-1). doi:10.1056/NEJMoa2206038
7. NCT04881760 — A Study of Retatrutide (LY3437943) in Participants Who Have Obesity or Are Overweight
8. NCT05929066 — TRIUMPH-1
9. NCT05882045 — TRIUMPH-3
10. Knerr PJ et al. J Med Chem. 2022. Design of the tri-agonist peptide LY-3437943.

Material for research use only. It does not constitute a clinical recommendation.

References

Material for research use only. The following primary sources support the scientific claims of this article:

1. Jastreboff AM, Kaplan LM, Frías JP, et al. Triple-hormone-receptor agonist retatrutide for obesity — a phase 2 trial. N Engl J Med. 2023;389(6):514-526. doi:10.1056/NEJMoa2301972. PMID 37366315.
2. Eli Lilly and Company. Retatrutide en TRIUMPH-4 (Fase 3; obesidad/sobrepeso con osteoartritis de rodilla): resultados topline. Comunicado de prensa; 11 dic 2025. (resultados preliminares, aún sin revisión por pares)

Products available at EXOMA

• Retatrutide