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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

RetatrutidevsTirzepatide

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 dual-action powerhouse that targets both GIP and GLP-1 receptors, delivering the most dramatic weight loss results ever seen in a medication—averaging over 20% body weight reduction while also crushing blood sugar levels in people with diabetes.

Weight ManagementWeight Management

At a Glance

Quick
comparison

Dose Range

Retatrutide

1–12 mg

Tirzepatide

2.5–15 mg

Frequency

Retatrutide

Once weekly

Tirzepatide

Once weekly

Administration

Retatrutide

Subcutaneous injection

Tirzepatide

Subcutaneous injection

Cycle Length

Retatrutide

12+ weeks

Tirzepatide

Ongoing/indefinite

Onset Speed

Retatrutide

Moderate (1-2 weeks)

Tirzepatide

Moderate (1-2 weeks)

Evidence Level

Retatrutide

Moderate human trials (Phase 1-2)

Tirzepatide

Strong human trials (Phase 3 or FDA approved)

Efficacy

Benefit
ratings

Retatrutide
Tirzepatide

Weight Loss Power

Retatrutide98%
Tirzepatide0%

Metabolic Health

Retatrutide95%
Tirzepatide0%

Appetite Control

Retatrutide94%
Tirzepatide97%

Weight Loss

Retatrutide0%
Tirzepatide99%

Blood Sugar Control

Retatrutide0%
Tirzepatide96%

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

Tirzepatide

Molecular Formula

C225H348N48O68

Molecular Weight

4813.45 g/mol

Half-Life

Approximately 5 days (120 hours)

Bioavailability

~80% (subcutaneous)

CAS Number

2023788-19-2

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.

Tirzepatide

starting

2.5 mg

Once weekly

4 weeks

This introductory dose helps your body adjust to the medication and minimizes GI side effects. Don't expect much weight loss yet—this phase is all about building tolerance. Think of it as your body's training wheels period.

standard

5-10 mg

Once weekly

4+ weeks at each dose

After 4 weeks at 2.5mg, increase to 5mg. Stay here for at least 4 weeks, then move to 7.5mg, then 10mg. This gradual climb reduces side effects while ramping up the weight loss. Most people start seeing serious results at 5-10mg doses.

advanced

12.5-15 mg

Once weekly

Ongoing/maintenance

The 15mg dose delivers maximum weight loss—averaging over 20% of body weight in trials. Continue increasing by 2.5mg every 4 weeks until reaching 15mg or your optimal maintenance dose. This is where the jaw-dropping results happen.

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.

Tirzepatide

People Who Want Maximum Weight Loss Results

If you're serious about losing significant weight, tirzepatide delivers results that were previously only achievable through bariatric surgery. Clinical trials showed average weight loss exceeding 20% of body weight—that's 50+ pounds for someone starting at 250 pounds. No other medication comes close.

Those Who Haven't Succeeded with Semaglutide

Thanks to its dual GIP/GLP-1 mechanism, tirzepatide often works better for people who had limited results with GLP-1-only drugs like semaglutide. The added GIP activation provides extra metabolic benefits that can break through plateaus and deliver superior weight loss.

People with Type 2 Diabetes Needing Aggressive Control

Head-to-head trials proved tirzepatide beats semaglutide for blood sugar control. The average HbA1c reduction of over 2 percentage points means many people can dramatically reduce or eliminate other diabetes medications. It's a genuine game-changer for metabolic health.

Individuals Looking to Transform Their Relationship with Food

Tirzepatide doesn't just reduce hunger—it fundamentally changes how food appeals to you. Users describe feeling free from constant food thoughts, finding it easy to stop eating when satisfied, and losing interest in formerly irresistible treats. It's not willpower—it's biochemistry working for you.

Safety Profile

Side
effects

Retatrutide

Common

  • Nausea
  • Diarrhea
  • Constipation
  • Decreased appetite

Uncommon

  • Increased heart rate
  • Injection site reactions

Serious

  • Pancreatitis
  • Gallbladder problems

Tirzepatide

Common

  • Nausea
  • Diarrhea
  • Decreased Appetite
  • Vomiting

Uncommon

  • Gallbladder Problems
  • Hair Thinning (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

Tirzepatide

Evidence Level

Strong human trials (Phase 3 or FDA approved)

FDA Status

FDA approved for this use

Safety Overview

Tirzepatide has been extensively studied in the SURPASS (diabetes) and SURMOUNT (obesity) trial programs, involving thousands of participants over multiple years. The FDA approved it after thorough safety review. While GI side effects are common (especially during dose increases), they're typically mild to moderate and improve over time. Serious adverse events are rare. The SURPASS-CVOT trial is ongoing to evaluate long-term cardiovascular outcomes.

Contraindications

  • xPersonal or family history of medullary thyroid carcinoma (MTC)
  • xMultiple Endocrine Neoplasia syndrome type 2 (MEN2)
  • xHistory of serious allergic reaction to tirzepatide or any GLP-1/GIP medication
  • 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 Tirzepatide if...

  • Maximum weight loss results
  • Long-term obesity management
  • Type 2 diabetes control
  • Metabolic health improvement
Retatrutide vs Tirzepatide — Peptide Comparison | Peptide Initiative