Hectorite A natural mineral, derived from bentonite clay.

Hexahydroxystearate/hexastearate/hexarosinate Synthetic ingredients derived from Stearic acid; used in small quantities in lipsticks, blushers, eyeliners, etc.

Hexyl laurate See Lauric acid under ‘L‘ – here; a mild and gentle emollient which is non-irritating and gives a velvety feel to skin.

Hexyl cinnamal A fragrance ingredient that is a mixture of Heyxyl alcohol and Cinnamic acid; cinnamates can be allergenic.

Hexyldecanol See Cetyl alcohol under ‘C‘ – here. Used as an emollient and an exfoliant, too.

Hexyldecyl laurate Mostly used for its skin conditioning powers; see Lauric acid under ‘L‘ – here.

Hexylene glycol A synthetic solvent which can in some cases cause irritation to skin, eyes and mucous membranes.

Hyaluronic acid A natural moisturiser which is found in high concentrations in the skin (and can be derived from animal or non-animal sources, ie from bacterial fermentation). It’s incredibly widely used.

Hydrogenated castor oil Hydrogenation is the process of adding natural hydrogen gas, under pressure, to oils – which solidifies them. It can be useful in the manufacture of natural cosmetics because it takes the place of chemicals that do the same job – although there are still discussions going on as to whether it should be allowed for Soil Association organically-certified cosmetics. (Hydrogenation is not allowed for organic foodstuffs, because of potential health risks; however, we only ingest a small amount of cosmetics – even lipsticks – so the debate is whether that’s relevant when it comes to skincare, bodycare and make-up.) So Hydrogenated castor oil is simply castor oil that’s been solidified in this way.

Hydrogenated coco glycerides See above – this is basically an ingredient of coconut oil that has been solidified.

Hydrogenated coconut oil See above.

Hydrogenated cottonseed oil See above.

Hydrogenated palm glycerides See above – in this case, the source is Palm oil.

Hydrogenated palm glycerides citrate See above.

Hydrogenated palm kernel glycerides See above.

Hydrogenated palm oil See above.

Hydrogenated vegetable oil See above.

Hydrogenated polyisobutene In this case, a synthetic ingredient (rather than a natural oil), which is again used as a moisturiser and skin conditioner.

Hydrolysed hibiscus esculentus extract See above – here from the Hibiscus plant.

Hydrolysed mucopolysaccharides This is a mixture of polysaccharides (sugars), derived from animal connective tissue – so a product with this ingredient would not be suitable for vegans, for instance. Useful for its water-binding properties.

Hydrolysed whole wheat protein An ingredient derived from wheat protein by the use of an acid or enzyme.

Hydroxycitronellal Generally used as a fragrance element, this synthetic ingredient is a known irritant.

Hydroxyisohexyl 3-cyclohexene carboxaldehyde An aldehydyic fragrance ingredient. (NB Coco Chanel was the first to popularise aldehydes in perfumery when Ernst Beaux created the legendary Chanel No. 5 for her – so these ingredients have been around since the 1920s.) Must be listed on ingredients labels – unlike so many thousands of fragrance ingredients – because it is a known irritant and sensitiser.

Hydrolysed wheat gluten See above for wheat protein.

Hydrolysed sweet almond protein See above – in this case, the ingredient is derived from sweet almond.

Hydroxyisohexyl 3-cyclohexene carboxaldehyde A synthetic aldehydic fragrance ingredient.

Hydroxyethylcellulose A modified cellulose ingredient (from plant cells, particularly wood pulp), used as a binding ingredient, stabiliser and thickener.

Hydroxypropyl methylcellulose Another cellulose-derived ingredient which, with foaming properties. In some cases it can be a mild skin and eye irritant, but it is also used as a food additive.

Hydroxypropyl starch phosphate Derived from starch, and used for its cleansing and thickening action in body washes, shampoos, wet wipes, etc.