A great serum can only do its job if your skin is ready to receive it. Start with clean, slightly damp skin, not soaking wet, but freshly cleansed and patted dry.
Use 2–3 drops for the face and neck. Warm the serum between your fingertips, then press it gently into the skin rather than rubbing. This technique helps the actives penetrate without unnecessary friction.
Wait 60 seconds before applying your next product. This gives the GHK-Cu time to absorb before you seal it in with cream or tallow.
Morning or night, the same principles apply. In the morning, always finish with SPF. At night, follow with your richest moisturiser for overnight repair.