Thymalin vs MK-677 (Ibutamoren)
A detailed comparison to help you understand the differences and choose the right peptide for your research goals.
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.
Full details →MK-677 (Ibutamoren)
MK-677, also known as Ibutamoren, is an orally active growth hormone secretagogue. Unlike peptides, it can be taken orally and has a long half-life, providing 24-hour GH elevation.
Full details →Side-by-Side Comparison
| Aspect | Thymalin | MK-677 (Ibutamoren) |
|---|---|---|
| Mechanism | Regulates the ratio of T-cell subpopulations, stimulates cellular immunity, and enhances phagocytosis. Also affects neuroendocrine regulation and may influence melatonin production. | Acts as a potent, selective agonist of the ghrelin receptor (GHS-R1a). Increases GH and IGF-1 levels without affecting cortisol. Mimics ghrelin's GH-releasing effects. |
| Typical Dosage | Clinical protocols: 5-20mg daily intramuscularly for 3-10 days. Often cycled 1-2 times per year for maintenance. | Typical dosing: 10-25mg taken orally once daily. Often taken at night due to sleep benefits and appetite increase. |
| Administration | Intramuscular injection. Usually administered in short courses rather than continuously. Often combined with Epithalamin for anti-aging protocols. | Oral administration (capsule or liquid). Can be taken with or without food. Long half-life allows once-daily dosing. |
| Side Effects | Generally well-tolerated. May cause injection site reactions or temporary flu-like symptoms as immune function is modulated. | Increased appetite and water retention are most common. May cause lethargy, vivid dreams, and mild numbness. Can affect blood glucose and insulin sensitivity. |
| Best For |
What They Have in Common
Both Thymalin and MK-677 (Ibutamoren) are commonly used for: