Thymosin Alpha-1 vs Follistatin

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

Thymosin Alpha-1

Thymosin Alpha-1 is a peptide naturally produced by the thymus gland that plays a crucial role in immune system modulation. It is approved in over 35 countries for various conditions including hepatitis B and C.

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Follistatin

Follistatin is a glycoprotein that inhibits myostatin, the protein responsible for limiting muscle growth. By blocking myostatin, follistatin can theoretically allow for increased muscle development beyond natural limits.

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Side-by-Side Comparison

AspectThymosin Alpha-1Follistatin
MechanismEnhances T-cell function and maturation, stimulates dendritic cell activity, and modulates cytokine production. Promotes the differentiation of stem cells into mature T lymphocytes.Binds to and neutralizes myostatin and activin, both of which are negative regulators of muscle mass. This removes the natural brake on muscle growth, allowing for enhanced hypertrophy.
Typical DosageClinical dosing typically ranges from 1.6mg to 6.4mg administered subcutaneously 2-3 times weekly. Research protocols may vary.Research protocols typically use 100-300mcg daily, though optimal dosing is not well established. Gene therapy approaches have also been studied.
AdministrationSubcutaneous injection. Often used in cycles or as part of comprehensive immune support protocols.Subcutaneous injection. Different isoforms exist (FS344, FS315) with varying properties. Requires careful sourcing due to complexity.
Side EffectsGenerally well-tolerated. Rare side effects include injection site reactions, mild flu-like symptoms, and temporary fatigue.Limited human data. Theoretical concerns about effects on other organs where activin signaling is important.
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Key Differences

Unique to Thymosin Alpha-1:

Unique to Follistatin:

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