Anyone over the age of 30 will know that a retinol-based skincare product is a must-have in the fight against fine lines and visible signs of ageing. However, as many of us with reactive or sensitive complexions will have discovered, not every retinol formula will deliver the miracles we expected. From redness to flaking and dryness, I've experienced all of the worst side effects of using the hero ingredient, which is why I need to be careful when I try a new product.