Enriched Grapefruit Treatment The Angel En Provence Grapefruit Straighten Treatment is specifically designed chemically-stressed hair! Containing Grapefruit extract and Vitamin C, this treatment helps to restore hair strands by adding deep nourishment. Leaving hair feeling softer, straighter and with an added glow. How to use: Apply after shampoo, leave in for 5-10 minutes. Rinse thoroughly.