Start with identity
Record the complete product name and intended area. Many brands sell facial serums, scalp treatments and advanced versions with overlapping words. Then select the country and pack size. A search thumbnail is not a reliable substitute for the current product page.
For this directory, “The Ordinary” means the Multi-Peptide Serum for Hair Density. “Neurogan” means the GHK-Cu Hair & Scalp Serum reviewed here, not its facial serum or a different dual-peptide version. Those distinctions prevent a comparison from drifting between products.
Read the ingredients as facts
Look for named peptides and note scent ingredients, including aromatic oils. If a product gives a percentage, identify whether it refers to a single ingredient or a supplier blend. Avoid inferring an exact amount from the ingredient’s position in the list.
A long list is not proof of superior performance, and a short list is not proof of safety. Keep the ingredient facts separate from the brand’s mechanism story and from evidence about what the complete formulation has achieved.
Check the purchase you will actually make
Confirm whether the default selection is a one-time order or a subscription. Include delivery, taxes and the cost of obtaining the same formula again. Read the merchant’s rules for opened cosmetic returns rather than assuming a long returns window covers every circumstance.
Save a dated copy of the product name and ingredients with your receipt. If the formula changes later, this gives you a better reference than a memory of the packaging. Our review dates refer to source checks, not to personal use of the products.
Sources & further reading
Product pages establish brand claims and label facts. They do not independently validate efficacy. Sources checked 14 September 2026.
- The Ordinary: Multi-Peptide Serum for Hair Density — official product and ingredients
- Divi: Scalp Serum — official product and ingredients
- Neurogan Health: GHK-Cu Hair & Scalp Serum — official product and ingredients
