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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

TabimorelinvsMK-677 (Ibutamoren)

An investigational oral growth hormone secretagogue that stimulates GH release through ghrelin receptor activation, though development was discontinued due to drug interaction concerns.

The oral growth hormone secretagogue that tricks your body into producing more GH — no needles required.

Growth HormoneGrowth Hormone

At a Glance

Quick
comparison

Dose Range

Tabimorelin

100–500 mg

MK-677 (Ibutamoren)

10–25 mg

Frequency

Tabimorelin

Once daily

MK-677 (Ibutamoren)

Once daily

Administration

Tabimorelin

Oral (capsule or solution)

MK-677 (Ibutamoren)

Oral (capsule or liquid)

Cycle Length

Tabimorelin

4-6 weeks

MK-677 (Ibutamoren)

8-12 weeks

Onset Speed

Tabimorelin

Moderate (1-2 weeks)

MK-677 (Ibutamoren)

Moderate (1-2 weeks)

Evidence Level

Tabimorelin

Moderate human trials (Phase 1-2)

MK-677 (Ibutamoren)

Moderate human trials (Phase 1-2)

Efficacy

Benefit
ratings

Tabimorelin
MK-677 (Ibutamoren)

Growth Hormone Stimulation

Tabimorelin85%
MK-677 (Ibutamoren)0%

Convenience & Compliance

Tabimorelin90%
MK-677 (Ibutamoren)0%

Selectivity & Safety Profile

Tabimorelin75%
MK-677 (Ibutamoren)0%

Muscle and body composition

Tabimorelin0%
MK-677 (Ibutamoren)85%

Recovery and athletic performance

Tabimorelin0%
MK-677 (Ibutamoren)80%

Sleep quality and metabolic health

Tabimorelin0%
MK-677 (Ibutamoren)75%

Technical Data

Compound
specifications

Tabimorelin

Molecular Formula

C32H40N4O3

Molecular Weight

528.7 g/mol

Half-Life

Several hours (exact human half-life not published; dose-dependent pharmacokinetics)

Bioavailability

Orally active with dose-dependent bioavailability (increases at higher doses)

CAS Number

193079-69-5

MK-677 (Ibutamoren)

Molecular Formula

C27H36N4O5S

Molecular Weight

528.7 g/mol

Half-Life

4-6 hours (IGF-1 elevation persists ~24 hours)

Bioavailability

High oral bioavailability

CAS Number

159634-47-6

Applications

Best
suited for

Tabimorelin

+Stimulates growth hormone release from the pituitary gland through ghrelin receptor activation

+Orally active—no injections required, making it convenient for daily use

+Dose-dependent growth hormone and IGF-1 elevation at therapeutic doses

+Does not significantly raise ACTH, cortisol, or prolactin at most doses, showing better selectivity than some competing GH-releasing peptides

+Well-tolerated in short-term human studies with generally mild adverse effects

MK-677 (Ibutamoren)

Older Adults (60+) Seeking Body Composition Improvements

MK-677 was designed for aging populations. It restores GH and IGF-1 to youthful levels, increases lean mass, and improves physical function in people over 60. A 2-year clinical trial showed a 1.1 kg gain in fat-free mass with only modest fat gain—ideal for maintaining strength in older age.

Athletes and Fitness Enthusiasts Wanting Recovery Support

Oral dosing makes MK-677 convenient for athletes. It enhances muscle protein synthesis, speeds recovery after intense training, and supports lean mass building without the hassle of injections.

People with Chronic Wasting or Protein Deficiency

Clinical trials show MK-677 helps treat protein-energy wasting in kidney disease and other conditions. It stimulates appetite (a feature in these populations) and preserves muscle tissue—making it useful for those losing mass despite good nutrition.

Safety Profile

Side
effects

Tabimorelin

Common

  • Headache
  • Nausea
  • Appetite stimulation
  • Dizziness
  • Dry mouth

Serious

  • Drug-drug interactions via CYP3A4 inhibition

MK-677 (Ibutamoren)

Common

  • Increased appetite
  • Mild water retention or edema
  • Elevated fasting glucose

Uncommon

  • Joint or muscle pain
  • Carpal tunnel syndrome or nerve compression symptoms
  • Mild nausea or digestive upset

Serious

  • Glucose dysregulation and diabetes risk

Research Status

Safety
& evidence

Tabimorelin

Evidence Level

Moderate human trials (Phase 1-2)

FDA Status

Research compound

Safety Overview

Tabimorelin is an oral GHS-R agonist with preclinical and early clinical data indicating dose-dependent appetite stimulation (potentially problematic for weight-conscious users) and transient blood glucose elevation due to GH's insulin-antagonistic effects. No human safety database exists beyond Phase 1/2 studies—efficacy and long-term safety profile in humans remain incompletely characterized. Potential risks include carpal tunnel syndrome (documented with chronic GH therapy), arthralgias, and theoretical tumor growth acceleration, though these are extrapolated from GH physiology rather than directly observed in limited human exposure.

Contraindications

  • xActive or history of carcinomas (ghrelin receptor agonists may stimulate growth of certain tumors)
  • xConcurrent use of potent CYP3A4 substrates due to risk of dangerous drug-drug interactions
  • xUntreated thyroid dysfunction
  • xUncontrolled diabetes

MK-677 (Ibutamoren)

Evidence Level

Moderate human trials (Phase 1-2)

FDA Status

Research compound

Safety Overview

MK-677 has been studied in hundreds of humans over 2+ years and is generally well tolerated. Most side effects are mild and manageable, especially with lower starting doses. The lack of injection requirement makes it safer than injectable GH in terms of infection risk and sterility concerns. However, it is not FDA approved and should be viewed as a research compound.

Contraindications

  • xUncontrolled diabetes or severe glucose dysregulation
  • xActive cancer or high cancer risk requiring caution with IGF-1 elevation
  • xPregnancy or breastfeeding

Decision Guide

Which is
right for you?

Choose Tabimorelin if...

  • Stimulating growth hormone production in healthy individuals
  • Exploring GH secretagogue mechanisms in research settings
  • Patients preferring oral administration over injections

Choose MK-677 (Ibutamoren) if...

  • Building lean muscle mass and strength
  • Improving overall body composition in aging adults
  • Enhancing athletic recovery and performance
  • Supporting metabolic health and fat loss
Tabimorelin vs MK-677 (Ibutamoren) — Peptide Comparison | Peptide Initiative