GHK-Cu side effects and what's normal

The most common thing patients report with GHK-Cu is a sting when they inject. It is expected, and there are things that help.

Common and usually temporary

• Stinging or burning during and just after the injection. GHK-Cu is more acidic than the other peptides, and that is what causes it. It does not mean your vial is bad or that you are allergic. See "How do I store, handle, and inject GHK-Cu?" for the five things that help.
• Redness, itching, or a small lump where you injected. Common with any peptide. Rotating sites is the fix.
• A welt, redness or burning at the spot that is still there a day or two later. This is common with GHK-Cu and fades on its own over a few days. It is not a sign that something is wrong.

Less common

An allergic reaction, as with any peptide. This is rare.

Contact us if

• A side effect is severe, persistent, or getting worse instead of better. At the injection site, that means a welt or redness that is growing, spreading or warm to the touch, or one that is not fading after 3 days
• The sting is bad enough that you are considering stopping — there is a protocol for it and we would rather help you than lose you
• Anything feels wrong enough that you are unsure about your next dose
• You notice signs of an allergic reaction such as a rash, hives, or swelling. For trouble breathing or swelling of the face, lips or tongue, seek emergency care first, then let us know. This is different from the expected sting.