TB4-FRAG vs YK-11

A side-by-side comparison from PeptideSciences101, the open peptide reference.

Overview

TB4-FRAG and YK-11 are both performance & growth peptides, but they differ in mechanism, dosing, and regulatory status.

This page compares TB4-FRAG and YK-11 across their primary use, typical dosing, reported benefits and side effects, and U.S. regulatory status. For the full monograph on either compound — mechanism of action, clinical research, and references — follow the article links.

Side-by-side comparison

TB4-FRAGYK-11
CategoryPerformance & GrowthPerformance & Growth
Regulatory status (US)Research use onlyResearch use only
Typical dosage2-5 mgResearch protocols
Frequencyweeklyvaries
Reported benefitsSimilar to TB-500, potentially faster actionMuscle growth beyond genetic limits
Reported side effectsSimilar to TB-500Limited human studies

Key differences

Primary use. TB4-FRAG is categorised under Performance & Growth, while YK-11 falls under Performance & Growth. Because they target a similar goal, they are common alternatives to weigh against each other.

Regulatory status. TB4-FRAG: not FDA-approved; treated as a research compound. YK-11: not FDA-approved; treated as a research compound.

Dosing. TB4-FRAG is typically dosed at 2-5 mg (weekly). YK-11 is typically dosed at Research protocols (varies).

Can you stack them?

Some protocols combine peptides, but stacking TB4-FRAG and YK-11 has not been validated for safety or efficacy in controlled trials. Combining compounds can change their effects and risks. Nothing here is medical advice — consult a qualified healthcare provider before starting or combining any protocol.

Frequently asked questions

What is the difference between TB4-FRAG and YK-11?
TB4-FRAG and YK-11 are both performance & growth peptides, but they differ in mechanism, dosing, and regulatory status. TB4-FRAG is not FDA-approved; generally classified as a research compound, whereas YK-11 is not FDA-approved; generally classified as a research compound.
What is TB4-FRAG used for?
TB-500 fragment.
What is YK-11 used for?
Myostatin inhibitor.
Can you take TB4-FRAG and YK-11 together?
Some users combine peptides within a single protocol, but stacking TB4-FRAG and YK-11 has not been established as safe or effective in controlled trials. Neither this comparison nor PeptideSciences101 is medical advice — consult a qualified healthcare provider before combining any compounds.
Is TB4-FRAG or YK-11 FDA-approved?
TB4-FRAG is not FDA-approved; generally classified as a research compound. YK-11 is not FDA-approved; generally classified as a research compound.

Read the full articles

  • TB4-FRAG — full monograph: mechanism, research, dosing & references
  • YK-11 — full monograph: mechanism, research, dosing & references

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