Serum is not strictly required, but we recommend using a **sterile, water-based serum that is suitable for microneedling** to help the pen glide smoothly over the skin. Please avoid thick creams, oils, acids, retinol, or other irritating products during microneedling. Serum is not included with this M9 set and should be purchased separately.  

Currently, the M9 delivers the best results. The M8 is compatible with a wider range of needles. You can view the treatment results for each needle on the M8.