Strengthen the hair with the K18 Molecular Hair Repair Oil, a silicone-free hair oil to help leave the hair smoother and more manageable. Very highly rated product, RRP £65. The hair oil uses a blend of natural oils, including sunflower and avocado, and squalane and hemisqualane to nourish the surface while smoothing frizz and flyaways for smoother, softer hair without weighing down the strands.