Another great budget option, you only need a pea-sized amount of The Inkey List Hyaluronic Acid (£6) to make a difference to your skin. It is quite versatile, so it can be added direct to cleansed skin before layering on the rest of your skin care or added into your own moisturiser. It contains three different molecular weights of HA, which means it reaches different depths within the skin to ensure your complexion is hydrated deep down.