During sleep the epidermal (skin) stem produces cells that replace the aged ones. This generally occurs late at night - early morning, when we are at rest and our bodies not disturbed. It's one of the reasons our skin can appear more attractive in the morning.

Known as the lipid barrier, this is your body's first line of defence against environmental aggressors and microorganisms. Your skin cycle changes throughout the day in order to protect and defend against various different elements – for example, in the morning your skin is more sensitive.

Throughout the day, your skin's water content differs. Water loss (trans-epidermal water loss) is at its peak in the evening and at night, and makes the skin more permeable to topical treatments. That is why this is the best time for applying product and allowing it to work its magic.

Sebum is produced by your glands to lubricate the skin and hair, making them waterproof. When too much builds up and sits on your skin, it can cause blocked pores and result in acne. Sebum excretion is at its highest around midday and lowest upon waking or late in the evening.