The Serum
What is GHK-Cu?
GHK-Cu (Copper Tripeptide-1) is a small peptide made of three amino acids bound to copper. It is one of the most celebrated ingredients in modern skincare, used in skincare to help improve the look of firmness and elasticity.
What is PAL-150?
PAL-150 is the peptide complex in our serum: Palmitoyl Tripeptide-1 and Palmitoyl Tetrapeptide-7. These signal peptides are widely used to help improve the look of fine lines and firmness.
Why is the serum blue?
The natural blue tint comes from copper peptide. Color may vary from pale blue to slightly deeper or greenish tones between batches. This is normal for copper peptide formulas.
What size is the bottle?
Each bottle contains 2 fl oz. The Gift Set includes two full-size bottles.
Is it cruelty free and vegan?
Yes. The SIIS Copper Peptide GHK-Cu Collagen Support / Elasticity Serum is cruelty free, vegan and paraben free, and it is made in USA with globally sourced ingredients.
Where can I see the full ingredient list?
On the product page and on The Science page, as well as on the packaging.
Using SIIS
How do I use it?
Apply a small amount to clean face and neck twice a day, morning and night. Follow with moisturizer, and with broad-spectrum sunscreen during the day.
Can I use it with other products?
Yes, it layers beneath moisturizer and makeup. Many people prefer not to apply copper peptides in the same step as strong exfoliating acids or pure vitamin C; alternate them morning and night instead.
Is it suitable for sensitive skin?
Skin is personal. We recommend a patch test on a small area before first use. Discontinue use if irritation occurs.
Can I use it while pregnant or nursing?
Please consult your physician before use if you are pregnant, nursing or under medical care.
How should I store it?
Store in a cool, dry place away from direct sunlight, with the dropper closed tightly.
Orders
What does pre-order mean?
Our first production run is being finished. You can order now and we will ship your serum by December 1, 2026. If we cannot meet that date, we will tell you and you may cancel for a full refund.
How long does shipping take?
SIIS is open for pre-order, shipping is free within the United States, and pre-orders ship by December 1, 2026. Once we are shipping, orders are dispatched within 1–3 business days and standard delivery takes 3–7 business days. See Shipping & Returns for details, including what happens if we are delayed.
Can I return my order?
Yes, under the conditions described on our Shipping & Returns page.
Is SIIS available on Amazon?
We are preparing an Amazon listing. When it is live, you will find a link on our product page.
Is checkout secure?
Yes. Payments are processed by Stripe; SIIS never sees or stores your full card number.
How do I contact you?
Email info@siispeptides.com or use our contact form.
These statements have not been evaluated by the Food and Drug Administration. This cosmetic product is not intended to diagnose, treat, cure, or prevent any disease. For external use only. Discontinue use if irritation occurs.