Grapeseed oil can help promote hair growth in several ways. It nourishes brittle or damaged hair, treats dandruff and scalp issues, and repairs hair damaged from heat styling or chemicals. To use it, warm 2-3 tablespoons and massage into the scalp before washing hair. Alternatively, mix it with essential oils and apply it to freshly washed, towel-dried hair before rinsing after 30 minutes. Applying grapeseed oil 2-3 times per week can help restore hair condition.