Your skin regenerates between midnight and 12pm. But since many Hongkongers don't go to bed until 1am, it's important to use these hours to give your skin a boost. 'When you sleep, and right up until just before lunch, these are peak times for skin renewal, it's when the body detoxes,' says Elemis' international trainer Emer Gillen. 'There are three levels of detox. The first is internal, which involves drinking water, eating a balanced diet and sticking to natural and organic ingredients where possible. The second is cellular, so it's important to ensure the skin is clean so the active ingredients in your skincare can do their job, providing a clear pathway for maximum impact on the skin. This is also why it's so important to have a night cream that's richer than the day cream. The last level is external which involves body brushing and exfoliation. 'It's not just what's happening on the surface of your skin, but what's going on in your lifestyle that will have an impact on your skin's ability to regenerate, detoxify and oxygenate. At night, we don't have external pollution factors and we're in a more controlled environment. When you're more relaxed your skin is more open to absorbing nutrients. This is how sleep promotes absorption of nutrients by the skin. The average time for skin to regenerate is 28 days. In this time new skin and cells grow but as we get older this process slows down, so we need to stimulate this regeneration process.'