Which peptide causes the most weight loss?

In clinical trials, retatrutide (24.2%) has shown the greatest weight loss, followed by tirzepatide (22.5%) and semaglutide (14.9%). However, retatrutide is investigational, while semaglutide and tirzepatide are FDA-approved. The clinical evidence base for these GLP-1 class drugs is far more extensive than for research peptides.

What is body recomposition?

Body recomposition refers to the simultaneous reduction of body fat and preservation (or gain) of lean muscle mass. This requires compounds that partition calories toward muscle and away from fat storage, often combining lipolytic and anabolic peptides in research protocols.

Are fat loss peptides permanent?

Clinical data from GLP-1 agonist trials shows that weight regain occurs after discontinuation in most patients. The STEP 1 extension trial showed two-thirds of weight loss was regained within one year of stopping semaglutide. This suggests these compounds manage weight rather than permanently resetting body composition.

Fat Loss & Body Recomp

Fat loss research peptides work through three primary mechanisms: appetite suppression (GLP-1 agonists), direct lipolysis (GH-pathway compounds), and increased energy expenditure (metabolic modulators). The recent revolution in GLP-1 receptor agonists has produced the most clinically validated weight loss compounds in history, while research peptides targeting GH secretion and mitochondrial function offer complementary approaches. Body recomposition, the simultaneous pursuit of fat loss and lean mass preservation, requires compounds that can shift the caloric partition toward muscle and away from adipose tissue.

Key Peptides for Fat Loss & Body Recomp.

FDA Approved

5/5

Semaglutide.

GLP-1 receptor agonist with the most extensive clinical evidence for weight management. Approved as Wegovy for chronic weight management with 14.9% mean body weight loss in STEP 1. Works primarily through central appetite suppression and delayed gastric emptying.

FDA Approved

5/5

Tirzepatide.

Dual GIP/GLP-1 agonist producing the highest weight loss of any approved pharmaceutical: 22.5% in SURMOUNT-1. The dual mechanism provides complementary metabolic benefits beyond what GLP-1 alone achieves.

Investigational

4/5

Retatrutide.

Investigational triple agonist (GIP/GLP-1/Glucagon) that has shown 24.2% weight loss in Phase 2. The glucagon component adds energy expenditure and hepatic fat oxidation to the appetite-suppressive effects of GIP/GLP-1.

Category 1

3/5

AOD-9604.

Modified fragment of growth hormone (176-191) that retains the lipolytic activity of GH without its growth-promoting or diabetogenic effects. AOD-9604 stimulates lipolysis and inhibits lipogenesis through a GH-receptor-independent mechanism.

FDA Approved

5/5

Tesamorelin.

FDA-approved GHRH analog that specifically targets visceral adipose tissue reduction. Preserves the natural GH pulsatile release pattern, producing selective visceral fat loss that is difficult to achieve through caloric restriction alone.

Category 1

3/5

MOTS-C.

Mitochondrial-derived peptide that activates AMPK, the master metabolic sensor, mimicking exercise signaling at the cellular level. Enhances glucose uptake, fatty acid oxidation, and metabolic flexibility without directly affecting appetite.

Research

3/5

5-Amino-1MQ.

NNMT inhibitor that increases cellular energy expenditure by restoring NAD+ availability. Works through a unique mechanism distinct from both GLP-1 agonism and GH-pathway approaches, potentially complementing either.

◆ Recommended Stack: The Recomp Stack

CJC-1295/Ipamorelin + AOD-9604 + MOTS-C. Combines GH optimization for lean mass preservation, targeted lipolysis through the GH fragment, and AMPK-driven metabolic enhancement for a comprehensive body recomposition research framework.

View Full Protocol →

Fat Loss & Body Recomp.

Key Peptides for Fat Loss & Body Recomp.

Semaglutide.

Tirzepatide.

Retatrutide.

AOD-9604.

Tesamorelin.

MOTS-C.

5-Amino-1MQ.

◆ Recommended Stack: The Recomp Stack

Frequently Asked Questions.