Sermorelin vs Thymalin

A detailed comparison to help you understand the differences and choose the right peptide for your research goals.

Sermorelin

Sermorelin is a synthetic analog of GHRH consisting of the first 29 amino acids of the natural hormone. It was previously FDA-approved for GH deficiency diagnosis and treatment in children.

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Thymalin

Thymalin is a polypeptide preparation derived from calf thymus. Developed in Russia, it has been used for decades to support immune function and has shown potential anti-aging effects in long-term studies.

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Side-by-Side Comparison

AspectSermorelinThymalin
MechanismBinds to GHRH receptors in the pituitary gland to stimulate natural GH production and release. Maintains the body's natural feedback mechanisms for GH regulation.Regulates the ratio of T-cell subpopulations, stimulates cellular immunity, and enhances phagocytosis. Also affects neuroendocrine regulation and may influence melatonin production.
Typical DosageTypical dosing: 200-500mcg administered once daily, usually before bed. Some protocols use twice daily dosing.Clinical protocols: 5-20mg daily intramuscularly for 3-10 days. Often cycled 1-2 times per year for maintenance.
AdministrationSubcutaneous injection, preferably at bedtime to work with natural GH release patterns. Can be combined with GHRPs for synergistic effects.Intramuscular injection. Usually administered in short courses rather than continuously. Often combined with Epithalamin for anti-aging protocols.
Side EffectsGenerally well-tolerated. May cause injection site reactions, headache, flushing, or dizziness. Less side effects than direct GH administration.Generally well-tolerated. May cause injection site reactions or temporary flu-like symptoms as immune function is modulated.
Best For

What They Have in Common

Both Sermorelin and Thymalin are commonly used for:

Key Differences

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