Comparison

TirzepatideRetatrutide

Both peptides are from Eli Lilly — Tirzepatide is the dual GLP-1/GIP agonist (approved), Retatrutide is the triple GLP-1/GIP/glucagon agonist (Phase 3). The comparison is between the established standard and its successor.

Spec	A Tirzepatide	B Retatrutide
Mechanism	GLP-1 + GIP dual	GLP-1 + GIP + glucagon triple
Weight loss	22.5% / 72 weeks	24.2% / 48 weeks
Regulatory status	FDA approved (2022/2023)	Phase 3 (TRIUMPH-1, expected 2026-2027)
Additional effect	GIP — thermogenesis, lipid metabolism	Glucagon — energy expenditure, hepatic lipolysis
Side effects	GI (nausea, vomiting), known	GI + higher heart rate from glucagon component

Choose A when

Tirzepatide

For research with an approved compound and accessible clinical protocols.

See full profile

Choose B when

Retatrutide

For exploring the newest generation of metabolic peptides and the triple mechanism.

See full profile

Verdict

Retatrutide is stronger on absolute weight loss but Tirzepatide is fully approved — for production protocols, that matters.

Other comparisons

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Semaglutide vs Tirzepatide

Semaglutide vs Retatrutide

BPC-157 vs TB-500

Ipamorelin vs CJC-1295

Last reviewed: 6 May 2026by PeptidLabs Editorial

Comparison

TirzepatideRetatrutide

Spec	A Tirzepatide	B Retatrutide
Mechanism	GLP-1 + GIP dual	GLP-1 + GIP + glucagon triple
Weight loss	22.5% / 72 weeks	24.2% / 48 weeks
Regulatory status	FDA approved (2022/2023)	Phase 3 (TRIUMPH-1, expected 2026-2027)
Additional effect	GIP — thermogenesis, lipid metabolism	Glucagon — energy expenditure, hepatic lipolysis
Side effects	GI (nausea, vomiting), known	GI + higher heart rate from glucagon component

Choose A when

Tirzepatide

For research with an approved compound and accessible clinical protocols.

See full profile

Choose B when

Retatrutide

For exploring the newest generation of metabolic peptides and the triple mechanism.

See full profile

Verdict

Retatrutide is stronger on absolute weight loss but Tirzepatide is fully approved — for production protocols, that matters.

Other comparisons

Keep exploring

Semaglutide vs Tirzepatide

Semaglutide vs Retatrutide

BPC-157 vs TB-500

Ipamorelin vs CJC-1295

Last reviewed: 6 May 2026by PeptidLabs Editorial