Alpha-Hydroxy Acids, often called fruit acids. AHAs are now appearing in an ever wider range of products, and are derived from natural ingredients, including grapes, apples, olives and milk. They act to speed up exfoliation by dissolving the ‘intercellular glue’ (which bonds dead, flaking cells to the skin’s surface), uncovering the smooth skin beneath. When first launched they were touted as the wonder anti-ageing ingredient for the nineties. But it has since emerged that they should be treated with caution as they can prove too harsh for fragile, sensitive and delicate skins; at any sign of irritation or lingering redness, discontinue use.

Antioxidants, found mostly in moisturisers, make-up and sun preparations. These are vitamins - betacarotene (the precursor of vitamin A), C and E - that help combat damage from free radical attack, which is triggered by exposure to sun, pollution and cigarette smoke. (According to research from Estée Lauder’s laboratories, smoking is at least as damaging to skin as the sun.) Free radicals act like ‘cellular terrorists’, attacking collagen, cell membranes and the skin’s lipid layer, while antioxidants ‘mop up’ free radicals in the skin. Experts are still divided over the effectiveness of antioxidants when mixed into moisturisers, although beauties have long sworn by the benefits of breaking open a vitamin E capsule and smearing it on the skin. But for anyone who’s exposed to sun/smoke/pollution (and that means all of us), they would seem to be worthwhile insurance.

Beta-Hydroxy Acids: These natural acids are close relations to AHAs and work in much the same way, speeding up cell turnover. The best known is salicylic acid (from willow bark). The same cautions apply: BHAs are acknowledged irritants, and anyone who experiences irritation should stop using them straight away.

Ceramides, mostly used in skin creams. These lipids, found in the skin’s intercellular cement, help stabilise skin structure by retaining moisture. They are therefore primarily of benefit to older, dry or damaged skins and are not necessary for healthy, young skins.

Collagen/Elastin are vital elements in the skin’s supporting structure, required for skin elasticity and smoothness; over time, production slows, leading to sags and bags. Collagen-containing creams and masks may be useful as surface moisturisers.

Enzymes, mostly found in moisturisers and masks. Enzyme exfoliants are a relatively new type of naturally derived ‘anti-ageing’ ingredient (often from papaya); they gently and thoroughly rid the surface layer of dead cells without harming living cells or irritating the skin.

Humectants are ingredients which attract moisture from the air to the surface of the skin, and are valuable ingredients in moisturisers or facial sprays for dry skins. Humectants include glycerine, sorbitol, squalene and urea.

Liposomes are high-tech skincare ‘rockets’ which can be launched into the epidermis and deliver their moisturising cargo deeper than would otherwise be possible, so helping to fill in the gaps between the intercellular cement. Afterwards the skin should feel - and look - intensively moisturised.

Nanospheres, a fancy term for small, rounded particles, which are ‘second generation’ liposomes.

Natural Moisturising Factors: Hyaluronic acid, sodium PCA and linolenic acid are all naturally present in the skin and come under the umbrella of NMFs. When applied in a cosmetic cream, they act as a natural, light moisturiser.

Oxygen is now in some skincare formulations. Oxygen delivered to the skin’s surface is supposed to improve cellular activity and turnover. But the best way to provide your skin with oxygen remains a brisk walk, or other physical activity (including sex).

Panthenol/Pro-Vitamin B5 is derived from vitamin B. Gentle and non-irritating, it can have a cosmetic and temporary ‘skin-plumping’ effect, is highly conditioning and is also an ingredient in hair products.

pH is a term often seen on packaging denoting acid balance. Your skin is naturally slightly acid, with a pH between 4.5 and 5.5. The correct balance can be disturbed by the use of soaps (most of which are strongly alkaline) and some cosmetics which are not acid-balanced. This is particularly the case if your skin is sensitive, excessively dry or oily, or is prone to acne.