Work out what’s in your beauty products with our handy guide.

Collagen is a hydrating ingredient. Applied to the surface of your skin, it's a great moisturiser, but it doesn't stimulate your skin's underlying natural collagen production.

Glycolic acid is a sugar cane derivative, shown to be highly effective at resurfacing and renewing the skin by chemically dissolving dead cells and lifting them off the skin's surface.

Hydroxy acids are fantastic for exfoliating. They come in several different strengths: mild microfoliants for sensitive skin; scrubs that force dead skin cells to be lifted; peels containing the enzymes bromalein and papain, which dissolve dead skin cells and are ideal for twenty-something skin; and exfoliants, such as glycolic and salicylic acid.

Peptides are amino acids linked together. In other words, they're the super ingredients that boost collagen production to keep skin youthful and supple.

Salicylic acid is a beta-hydroxy acid, found in aspirin and natural sources such as willow bark and sweet birch. Proven to be as effective as glycolic acid in the long term, but less aggressive and drying. Ideal for fighting spots.