No. Spectral DNC-N topical should not leave your hair oily or greasy. While it is a topical hair applicant, by nature you'll feel and see 'wet' look but should not feel greasy or oily as it's a water-based formula.
When applying, we do suggest spraying directly on the scalp, avoiding as much of the hair shaft as possible. We then recommend massaging the product into the scalp for 2-3 minutes until you feel that is has absorbed fully.