Follistatin vs AHK-Cu

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

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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AHK-Cu

AHK-Cu (Copper Tripeptide-3, Alanine-Histidine-Lysine Copper) is a copper peptide similar to GHK-Cu but with different properties. It's used for hair growth and skin rejuvenation applications.

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Side-by-Side Comparison

AspectFollistatinAHK-Cu
MechanismBinds 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.The copper-binding tripeptide stimulates collagen synthesis and may promote hair follicle enlargement. Works similarly to GHK-Cu but may have distinct receptor interactions.
Typical DosageResearch protocols typically use 100-300mcg daily, though optimal dosing is not well established. Gene therapy approaches have also been studied.Topical: 0.5-2% concentration in serums for skin or scalp applications. Often combined with other growth factors for hair formulations.
AdministrationSubcutaneous injection. Different isoforms exist (FS344, FS315) with varying properties. Requires careful sourcing due to complexity.Topical application to skin or scalp. Can be used with microneedling for enhanced penetration. May cause temporary blue-green tint at high concentrations.
Side EffectsLimited human data. Theoretical concerns about effects on other organs where activin signaling is important.Generally well-tolerated. May cause skin irritation in sensitive individuals. Temporary discoloration possible.
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Key Differences

Unique to Follistatin:

Unique to AHK-Cu:

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