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Peptide Database

Goals
Fat LossMuscle BuildingInjury HealingAnti-AgingCognitive EnhancementSleep OptimizationImmune SupportGut HealingSkin RejuvenationSexual Health
Peptides
Adipotide
Weight Management
AOD-9604
Weight Management
BPC-157
Healing & Recovery
Cagrilintide
Weight Management
CJC-1295
Growth Hormone
DSIP
Sleep & Recovery
Epithalon
Anti-Aging
GHK-Cu
Anti-Aging
GHRP-2
Growth Hormone
HCG
Hormone Support
Hexarelin
Growth Hormone
HGH
Growth Hormone
IGF-1 LR3
Growth Hormone
Kisspeptin
Hormone Support
Melanotan-2
Cosmetic
MOTS-C
Metabolic
NAD+
Anti-Aging
Oxytocin Acetate
Hormone Support
PEG-MGF
Recovery
PNC-27
Cancer Research
PT-141
Sexual Health
Retatrutide
Weight Management
Selank
Cognitive
Semaglutide
Weight Management
Semax
Cognitive
Sermorelin
Growth Hormone
Snap-8
Cosmetic
SS-31
Mitochondrial
TB-500
Healing & Recovery
Tesamorelin
Growth Hormone
Thymosin Alpha-1
Immune
Tirzepatide
Weight Management
Total Peptides: 32
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Peptide Comparison

RetatrutidevsSemaglutide

The world's first triple-action weight loss peptide that simultaneously activates three hormone receptors—GIP, GLP-1, and glucagon—delivering unprecedented weight loss results of up to 24% body weight in clinical trials.

The revolutionary once-weekly GLP-1 medication that helps your body feel full faster and longer, leading to significant weight loss while also protecting your heart—FDA approved and backed by some of the largest clinical trials in obesity medicine history.

Weight ManagementWeight Management

At a Glance

Quick
comparison

Dose Range

Retatrutide

1–12 mg

Semaglutide

0.25–2.4 mg

Frequency

Retatrutide

Once weekly

Semaglutide

Once weekly

Administration

Retatrutide

Subcutaneous injection

Semaglutide

Subcutaneous injection

Cycle Length

Retatrutide

12+ weeks

Semaglutide

Ongoing/indefinite

Onset Speed

Retatrutide

Moderate (1-2 weeks)

Semaglutide

Moderate (1-2 weeks)

Evidence Level

Retatrutide

Moderate human trials (Phase 1-2)

Semaglutide

Strong human trials (Phase 3 or FDA approved)

Efficacy

Benefit
ratings

Retatrutide
Semaglutide

Weight Loss Power

Retatrutide98%
Semaglutide0%

Metabolic Health

Retatrutide95%
Semaglutide0%

Appetite Control

Retatrutide94%
Semaglutide95%

Weight Loss

Retatrutide0%
Semaglutide98%

Heart Protection

Retatrutide0%
Semaglutide92%

Technical Data

Compound
specifications

Retatrutide

Molecular Formula

C221H342N46O68

Molecular Weight

4731 g/mol

Half-Life

~6 days (allows once-weekly dosing)

Bioavailability

High via subcutaneous injection

CAS Number

2381089-83-2

Semaglutide

Molecular Formula

C187H291N45O59

Molecular Weight

4113.58 g/mol

Half-Life

Approximately 7 days (168 hours)

Bioavailability

89% (subcutaneous); 0.4-1% (oral, with absorption enhancer)

CAS Number

910463-68-2

Protocols

Dosing
tiers

Retatrutide

starting

1-2 mg

Once weekly

4 weeks

Start low to let your body adjust. This minimizes the nausea and GI side effects that are most common when starting. Even at this low dose, you'll likely notice reduced appetite.

standard

4-8 mg

Once weekly

8-12 weeks

The sweet spot for most users. Clinical trials showed substantial weight loss at these doses with manageable side effects. Increase gradually (every 4 weeks) to reach this range.

advanced

12 mg

Once weekly

12+ weeks

Maximum studied dose delivering the most dramatic results—up to 24% weight loss. Only reach this after gradual titration and proving tolerance at lower doses. Side effects are more common but still manageable for most.

Semaglutide

starting

0.25 mg

Once weekly

4 weeks

This starting dose is designed to let your body adjust to the medication and minimize nausea. You probably won't see much weight loss yet—that's normal. This phase is all about getting your GI system used to the medication.

standard

0.5-1.0 mg

Once weekly

8+ weeks at each dose

After 4 weeks at 0.25mg, increase to 0.5mg. After another 4 weeks, move to 1.0mg. This gradual approach significantly reduces nausea and vomiting. Most people start seeing meaningful weight loss at the 0.5-1.0mg doses.

advanced

1.7-2.4 mg

Once weekly

Ongoing/maintenance

The 2.4mg dose (Wegovy) is the FDA-approved dose for chronic weight management. Continue increasing by 0.5mg increments every 4 weeks until reaching 2.4mg. This is where the most significant weight loss occurs—averaging 15% or more of body weight in trials.

Applications

Best
suited for

Retatrutide

Significant Obesity Management

If you need to lose a substantial amount of weight, retatrutide is showing unprecedented results. Phase 2 trials demonstrated average weight loss of 24% at the highest dose—that's nearly 60 pounds for someone weighing 250 lbs. No other medication has matched this.

Type 2 Diabetes with Obesity

Retatrutide tackles both problems at once. It dramatically improves blood sugar control (HbA1c reductions of up to 2%) while delivering major weight loss. The dual benefit makes it especially valuable for diabetics struggling with weight.

Metabolic Syndrome Warriors

If you're dealing with the cluster of issues that includes high blood sugar, excess belly fat, abnormal cholesterol, and high blood pressure, retatrutide's triple mechanism attacks multiple aspects of metabolic dysfunction simultaneously.

Fatty Liver Disease (MASLD)

Early research shows retatrutide may significantly reduce liver fat. For people with non-alcoholic fatty liver disease, this peptide offers hope through weight loss plus direct metabolic improvements that benefit liver health.

Semaglutide

People with Obesity Seeking Significant Weight Loss

If your BMI is 30 or higher (or 27+ with weight-related health conditions), semaglutide is currently one of the most effective non-surgical weight loss options available. Clinical trials show average weight loss of 15% of body weight—that's 30+ pounds for someone starting at 200 pounds.

Those Who've Struggled with Diet and Exercise Alone

Semaglutide works by changing the biological signals that drive hunger and cravings. If you've tried to lose weight through willpower alone and found yourself constantly battling hunger, this medication addresses that underlying biology rather than just telling you to eat less.

People with Type 2 Diabetes Needing Better Control

Originally developed for diabetes, semaglutide excellently controls blood sugar while also promoting weight loss—addressing two major health concerns simultaneously. It can often allow people to reduce or eliminate other diabetes medications.

Individuals at High Cardiovascular Risk

The SELECT trial proved that semaglutide reduces heart attacks, strokes, and cardiovascular death by 20% in people with obesity and existing heart disease—even without diabetes. It's one of the few weight loss medications proven to improve hard cardiovascular outcomes.

Safety Profile

Side
effects

Retatrutide

Common

  • Nausea
  • Diarrhea
  • Constipation
  • Decreased appetite

Uncommon

  • Increased heart rate
  • Injection site reactions

Serious

  • Pancreatitis
  • Gallbladder problems

Semaglutide

Common

  • Nausea
  • Constipation or Diarrhea
  • Decreased Appetite
  • Vomiting

Uncommon

  • Gallbladder Problems
  • Hair Loss (Telogen Effluvium)

Serious

  • Pancreatitis
  • Thyroid Tumors (Theoretical Risk)

Research Status

Safety
& evidence

Retatrutide

Evidence Level

Moderate human trials (Phase 1-2)

FDA Status

Research compound

Safety Overview

Retatrutide has shown a generally favorable safety profile in Phase 1 and Phase 2 clinical trials involving over 600 participants. Most side effects are gastrointestinal and tend to improve over time. The medication appears well-tolerated when doses are increased gradually. No major safety signals have emerged, but larger Phase 3 trials are still ongoing.

Contraindications

  • xPersonal or family history of medullary thyroid carcinoma (MTC)
  • xMultiple Endocrine Neoplasia syndrome type 2 (MEN 2)
  • xPregnancy or planning to become pregnant
  • xHistory of severe pancreatitis
  • xKnown allergy to GLP-1 receptor agonists

Semaglutide

Evidence Level

Strong human trials (Phase 3 or FDA approved)

FDA Status

FDA approved for this use

Safety Overview

Semaglutide has been studied in over 20,000 participants across multiple large clinical trials, making it one of the most thoroughly researched weight loss medications available. The FDA approved it after rigorous review of safety data. While GI side effects are common (especially early on), serious side effects are rare. The SELECT trial showed it actually reduces cardiovascular events, adding a safety benefit beyond just weight loss.

Contraindications

  • xPersonal or family history of medullary thyroid carcinoma (MTC)
  • xMultiple Endocrine Neoplasia syndrome type 2 (MEN2)
  • xHistory of serious allergic reaction to semaglutide
  • xCurrent or recent pancreatitis
  • xPregnancy or planning to become pregnant

Decision Guide

Which is
right for you?

Choose Retatrutide if...

  • Significant weight loss
  • Type 2 diabetes management
  • Metabolic health improvement
  • Body composition optimization

Choose Semaglutide if...

  • Significant weight loss
  • Long-term weight management
  • Cardiovascular risk reduction
  • Blood sugar control
Peptide ProRetatrutide vs Semaglutide — Peptide Comparison | Peptide Initiative