The science bit
Hyaluronic acid is naturally found in the dermis of the skin. It is essential for the volume and elasticity of the skin. As we age, the natural hyaluronic acid content of our skin decreases.
At the same time other skin changes occur as part of the ageing process, such as;
Oil production and the water content of our skin decreases, causing dryness and dehydration.
The skin also loses fat, leaving the skin less plump and lacking volume. The number of blood vessels supplying the outer layers of our skin also reduces resulting in dull, tired skin.
Natural ageing combined with external factors such as pollution, smoking and gravity means that our skin loses volume and elasticity which leads to the formation of lines and wrinkles.