"0.3% retinol is enough to give a good effect but also enough not to put the skin at risk or irritate the skin," continued Abi. "There are creams out there formulated at 1% and 2% but in my experience consumers don’t always use retinol properly. I liken the choice of retinol to buying medication for a cold or flu. If I go to the pharmacy and see a bottle of medicine and then spot the same medication in 'max strength', I'm going for the 'max strength' version. The moment we put very high retinol in front of people and tell them to use it once or twice a week, they tend not to follow that advice, especially if they see a result, and that puts skin at risk of irritation and also damage from the environment through UV exposure ."