The big skincare glossary: An A-Z of the ingredients you need to know

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Elizabeth Bennett and Jacqueline Kilikita
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Sort your acids, get to know your vitamins and brush up on everything in between with our handy skincare cheat sheet.

From alpha hydroxy acids to zinc, there are hundreds, if not thousands, of skincare ingredients promising your best complexion ever. But how can you possibly know what they all do? And are they even right for you? 

It can be all too overwhelming differentiating your niancinamide from your phytic acid - not to mention how and when to use them in your skincare routine. 

Now that we’ve got a little more time than usual, Stylist got to work decoding the most popular ingredients and their skin-boosting benefits…

A is for AHA 

What are AHAs?

Alpha hydroxy acids are a group of chemical compounds found naturally in fruits, milk, and sugar cane. The most common AHAs found in skincare products are glycolic acid (derived from sugar cane), lactic acid (found in sour milk) and citric acid (from lemons, oranges and other fruits).

How do AHAs benefit the skin?

While the term acid might seem intimidating, AHAs are a great gentle form of exfoliation that work on the surface of the skin by sleughing off dead skin cells to improve skin texture and tone. 

They have a myriad of benefits including diminishing the look of lines and wrinkles, improving skin’s firmness and reducing signs of sun damage such as dark spots.

Product pick: Pixi Glow Tonic, £18,

B is for BHA 

BHA Exfoliant

What are BHAs?

Beta hydroxy acid, known most commonly in skincare as salicylic acid, is a liquid, chemical exfoliant that helps shed dead skin cells.

How do BHAs benefit the skin?

Particularly beneficial for acne-prone or oily skin, salicylic acid penetrates the pore lining and exfoliates inside the pore to help reduce blackheads, whiteheads and to fade blemish scars.

Product pick: Paula’s Choice 2% BHA Liquid Exfoliant, £28,

This targeted treatment from wallet-friendly skincare experts Paula’s Choice 2% BHA contains soothing green tea and 2% salicylic acid. Apply directly on the affected areas for visible improvement or sparingly all over to maintain visible clarity. 

C is for Charcoal

What is charcoal?

Used in health and beauty treatments since Egyptian times, this black carbon and ash residue has impressive detoxifying abilities when used on the skin.

How does it benefit the skin?

Charcoal, specifically activated charcoal, can absorb up to 200 times its weight in impurities – making it a great choice for those suffering with blocked pores, congestion or acne.

Product pick: Glamglow Supermud Clearing Treatment, £44,

A hardworking mask that uses activated charcoal to attract toxins and dirt from the skin to leave your complexion both clearer and smoother. 

D is for DHA

What is it?

Dihydroxyacetone is an ingredient derived from sugar used in self-tanning products to change the colour of the skin.

How does DHA benefit the skin?

DHA reacts with amino acids found in the upper layers of skin to create the appearance of a tan. Dihydroxyacetone does not protect the skin from harmful UV rays.

Product pick: Isle of Paradise Medium Self Tanning Drops, £16.95,

For a natural and streak-free glow, mix a few drops of this with your normal moisturiser.

E is for Emollients 

What are emollients?

Supple lubricating ingredients that prevent water loss. Examples include plant oils, mineral oil, shea butter, cocoa butter, squalane and petrolatum.

How do they benefit the skin?

Emollients help nourish dry skin and improve skin’s softness by providing a barrier on the surface and locking in moisture.

Product pick: Kiehl’s Ultra Facial Moisturizer, £17.50,

A lightweight and easily absorbed moisturiser that uses squalane to hydrate skin all day long.

F is for Ferulic Acid 

What is it?

Ferulic acid is an organic compound found in plant cell walls used in skincare for its antioxidant properties.

How does ferulic acid benefit the skin?

Antioxidants have been shown to help combat ageing by diminishing the impact of skin-damaging free radicals. Additionally, ferulic acid can be used to improve the efficacy of vitamins C and E.

Product pick: Dr Dennis Gross Skincare Ferulic and Retinol Wrinkle Recovery Overnight Serum, £89,

A hat-trick of anti-ageing ingredients including cell-energising niacinamide, age-defying retinol and free radical-fighting ferulic acid.

G is for Glycerin

What is it?

Glycerin, also known as glycerol, is a type of lipid (fat) found naturally in the body. It can either be derived from a sugar fermentation process but is more frequently manufactured synthetically.

How does it benefit the skin?

A skin-replenishing ingredient, glycerin helps retain correct moisture levels and improve the appearance and texture of skin. Normally found as a base ingredient in both face and body moisturisers.

Product pick: Glossier Priming Moisturiser, £18,

This light-feeling moisturiser plumps the skin and creates a dewy canvas ideal for applying make-up.

 H is for Hyaluronic Acid 

What is it?

Hyaluronic acid is a polysaccharide molecule that is naturally found in the body. One of the chief components of connective tissue, it plays an important role in retaining moisture. Impressively, one molecule can hold up to 1000 times its own weight in water.

How does it benefit the skin?

Hyaluronic acid boosts the skin’s hydration levels which in turn makes skin more plump, firm and glowing.

Product pick: The Inkey List Hyaluronic Acid, £5.99,

A purse-friendly option when it comes to the hydrating hero. The 2% concentrated acid leaves skin looking smoother, hydrated and brighter.

I is for Iris

What is it?

Iris is a flowering extracted plauded for its anti-ageing abilities. It comes in two forms: Florentina extract and orris root.

How does iris benefit the skin?

A good natural alternative to chemical anti-ageing ingredients, iris is packed with antioxidants that protect the skin by neutralizing skin damaging free radicals.

Product pick: Decléor Aromessence Iris Concentrate£40.50,

An award-winning facial oil that harnesses the power of iris to increase cell turnover and reduce fine lines. 

J is for Jojoba Oil   

What is it?

A fragrance-free oil extracted from the plant of the same name. A rich source of numerous fatty acids, jojoba oil is unique in the fact it is almost identical in texture to the sebum in our skin.

How does it benefit the skin?

Jojoba oil is a great, non-greasy option for nourishing dry skin.

Product pick: MV Organic Pure Jojoba Oil, £32,

Supremely versatile and ideal for sensitive skin, this pure jojoba oil can be used as a make-up remover, cleanser or moisturiser.

K is for Vitamin K

What is vitamin K?

Alternatively known as phytonadione, the body needs this fat-soluble vitamin to assist with blood clotting.

How does it benefit the skin?

Vitamin K has been proven to accelerate skin healing and is used in products to help calm redness and irritation along with improving the appearance of dark circles.

Product pick: Goldfaden MD Bright Eyes£48,

This refreshing eye serum uses vitamin K to diminish visibility of dark circles alongside a cocktail of naturally derived ingredients - including seaweed extract, bran extract and jojoba oil - to improve hydration and brightness. 

L is for L-Ascorbic Acid

What is it?

L-ascorbic acid, otherwise referred to as vitamin C, is a potent antioxidant that fights free radicals and brightens skin tone.

How does L-ascorbic acid benefit the skin?

An all-round hero ingredient, it helps prevent signs of ageing by shielding skin from pollution as well as improving tone and firmness.

Product pick: Sunday Riley C.E.O. Rapid Flash Brightening Serum, £70,

This concentrated high-performance serum tackles the five signs of ageing - dullness, sensitivity, wrinkles, dehydration, uneven tone and premature fine lines - at swift speed. 

M is for Mandelic Acid

What is it?

Mandelic acid is a lesser-known AHA that is much gentler on the skin than its cousins glycolic and lactic.

How does mandelic acid benefit the skin?

It accelerates cell turnover by dissolving the bonds that hold skin cells together, improving overall texture and enhancing glow.

Product pick: DCL Multi-Action Penta Peel, £58,

A cocktail of five acids including mandelic work to banish dead skin cells to reveal a smoother, more radiant complexion in just five minutes. 

N is for Niacinamide

What is it?

Niacinamide is a form of vitamin B3, otherwise known as nicotinic acid. It is a water-soluble ingredient that is essential for skin hydration and repair.

How does niacinamide benefit the skin?

According to consultant dermatologist and British Skin Foundation spokesperson, Dr Anjali Mahto, niacinamide can “help reduce inflammation and pigmentation marks left behind by acne”. 

But that’s not all, as it strengthens the skin’s barrier function, increases hydration, regulates sebum production and provides protection against the environment.

Product pick: La Roche-Posay Effaclar Duo+, £17,

The ultimate non-comedogenic moisturiser for those with acne-prone skin, this harnesses niacinamide to reduce the appearance of spots and includes salicylic acid to unclog pores. It absorbs in seconds and leaves skin feeling matte and fresh for hours on end. 

O is for Oatmeal

What is it?

Oatmeal is made of oat grains, which are natural grains grown for their seeds. While they’re best known as breakfast, they have numerous skin benefits, too.

How does it benefit the skin?

“Oats are very gentle and good for sensitive skin types,” explains Kate Protopapas, skin expert and founder of Isla Apothecary. Thanks to their high lipid content, they are extremely moisturising, which makes them a brilliant ingredient for those with eczema or dermatitis-prone skin.

Product pick: Aveeno Cream with Natural Collodial Oatmeal, £7.49,

Star ingredient oatmeal soothes and intensely moisturises parched skin prone to itching and inflammation for up to 24 hours. 

P is for Probiotics

What are probiotics?

Just like ingestible probiotics, which aid in gut health, topical probiotics are ‘good bacteria’. Most beauty brands harness the lactobacillus type, which has usually been deactivated.

How do they benefit the skin?

According to the experts, probiotics have the ability to calm inflammation in the skin, speed up the repair of the skin’s barrier (banishing irritation and dryness) and defend the skin from environmental aggressors, such as pollution.

Some studies have even found that probiotic lactobaccilus has been effective in treating acne, as they feed the good bacteria and starve the bad ones.

Product pick: Gallinee Youthful Serum,  £45,

Filled to bursting with probiotics and prebiotics (the nutrients that feed the good bacteria), this serum takes taut, dull skin and makes it bouncy and radiant. After a week, our skin looked much clearer, too.

Q is for Quercetin 

What is it?

Quercetin is a natural compound found in fruits, vegetables and other types of food but it also has a myriad of skincare benefits.

How does it benefit the skin?

Quercetin is essentially a flavonoid, which means it has brilliant anti-inflammatory properties, reducing redness and puffiness. 

It also has antioxidant benefits and when applied topically, it can help shield the skin against free radicals such as pollution and UV, which can lead to fine lines and pigmentation. 

Product pick: De Mamiel Atmosphériques Exhale Daily Hydrating Nectar SPF30, £83,

Not a fan of unctuous moisturisers? Give this featherlight spritz a go, instead. It combines quercetin for environmental protection, SPF 30 for added defence against UV, and prickly pear seed oil, which is naturally packed with intensely moisturising vitamin E. Simply spray on after cleansing.

R is for Retinol

What is it?

Retinols belong to a class of compounds known as retinoids,” says Dr Mahto. “These agents are derived from vitamin A.”

How does retinol benefit the skin?

According to Dr Mahto, retinoids have repeatedly been shown in clinical trials to improve skin cell turnover and reduce the breakdown of collagen, resulting in bouncier skin.

Used as part of a nightly skincare routine, they are also very helpful in reducing fine lines, pigmentation, acne and marks left behind by spots, as they encourage skin cells to renew themselves at a lightning speed. 

Retinol is available in varying strengths and use should be gradually built up to avoid any skin irritation. If you’re a retinol novice, apply it to clean, dry skin two to three evenings a week and give your face a break with a retinol-free moisturiser in between, to keep redness, dryness and sensitivity at bay. 

Product pick: Beauty Pie Super Retinol Ceramide Boost Face Serum, £13.70 for members,

A little of this goes a very long way to blur pigmentation, fine lines and discolouration left behind by acne. Rather cleverly, the retinol is suspended in cell-building ceramides, refining lactic acid and hydration powerhouse hyaluronic acid, which makes this a brilliant option for those with sensitive skin.

S is for Sodium Bicarbonate

What is it?

Otherwise known as baking powder, this powdery white substance is a chemical compound made from both sodium ions and bicarbonate ions. It reacts on contact with water to make an effervescent fizz. 

How does sodium bicarbonate benefit the skin?

Sodium bicarbonate is widely used in carbonated clay masks. When activated, it forms a frothy foam that almost works like an exfoliator to chip away at deep-set grime and unblock congested pores. 

Product pick: Biore Baking Soda Blemish Cleansing Foam, £3.95,

Biore’s foaming cleanser blitzes blackheads and mops up excess oil to leave skin clean and refreshed, not tight or dry.

T is for Turmeric

What is it?

Turmeric is a bright orange-yellow powder typically used for flavouring food. Skin experts argue that it also has its place in skincare, which explains those bright, DIY face masks that keep flooding your Instagram feed.

How does turmeric benefit the skin?

According to Protopapas, turmeric is a good option for those with acne-prone skin as it is both an anti-inflammatory and anti-bacterial ingredient. DIY beauty-lovers can whip up their very own face mask with turmeric, honey and dead sea salt, but if that isn’t your thing…

Product pick: Isla Apothecary Refine + Radiate Beautifying Face Mask, £16.50,

Turmeric root powder in this all-vegan mask neutralises bad bacteria and leaves skin radiant. Isla Apothecary’s products are all made in small batches, which adds to their potency and freshness.

V is for Vitamin B5

What is it?

“Vitamin B5 is a very effective humectant,” explains facialist Kate Kerr. “This means it attracts and binds water to the skin.” 

How does vitamin B5 benefit the skin?

“It’s brilliant at improving skin hydration,” Kerr says. “It is also important in maintaining a strong barrier function, which, in turn, improves skin protection. It’s good for easily irritated skin types as it reduces itchiness, pain and discomfort.”

Product pick: Medik8 Hydra B5, £40,

If your face feels taut and uncomfortable after cleansing, treat it to a hit of this fast-absorbing serum. A double whammy of B5 and hyaluronic acid quench thirsty cells, repair damage and make skin plump.

W is for White Tea Leaf Extract

What is it?

White tea extract is a liquid substance derived from new buds and leaves of the tea plant, otherwise known as the Camellia Sinensis.

How does white tea leaf extract benefit the skin?

Studies show that it has a very high concentration of antioxidants. When applied topically, it provides great defence against free radicals such as pollution, which makes it perfect for city dwellers exposed to a daily onslaught of pollution, cigarette smoke and iron particles from train tracks (to name but a few environmental aggressors).

Product pick: Origins A Perfect World SPF 40 Moisturiser With White Tea, £35,

SPF 40 and antioxidant white tea extract in this creamy moisturiser work in tandem to block free radicals such as pollution and UV, which have been proven to lead to dullness, dehydration and fine lines.

X is for Xanthan Gum

What is it?

Xanthan gum is a polysaccharide, a substance derived from sugar. It is usually used as a thickening agent or as a substance which suspends preservatives in skincare products. Pick up any skincare product you own and you’re bound to see it on the back of the ingredients list.

How does xanthan gum benefit the skin?

There are less skincare benefits of xanthan gum and more for skincare products. As a thickening agent, it has the ability to alter the texture, notably making serums, moisturisers and cleansers more unctuous in consistency. 

Product pick: REN Evercalm Gentle Cleansing Gel, £22,

This clever gel cleanser transforms into a light and airy whip on contact with damp skin, dislodging everything from make-up to grime without ever making your face feeling taut or uncomfortable.

Y is for Yeast Extract

What is it?

Yeast extract is derived from yeast, which are microorganisms that fall under the fungus umbrella. But don’t let that put you off…

How does yeast extract benefit the skin?

According to research, yeast extract contains a high concentration of antioxidants, which reduce oxidative stress on the skin. It has also been proven to reduce sensitivity and to keep moisture on lockdown in dry, dehydrated skin. 

Product pick: Laura Mercier Repair Creme £79,

The yeast extract in this satin-like formula helps to plump and restore the skin as well as reduce the appearance of fine lines and wrinkles. Additionally, the peptide complex and deep sea water helps cell renewal, encouraging a healthy glow.

Z is for Zinc 

What is it?

Zinc is a silvery, white-toned metal. You’ll probably be most familiar with it in supplement form, but according to experts, it’s also a key mineral for healthy, functioning skin when applied topically. 

How does zinc benefit the skin?

Dr Mahto says acne or blemish-prone skin can benefit from products containing zinc. Why? It has the ability to regulate sebum production, preventing clogged pores, and to repair damaged skin.

Product pick: Alpha-H Clear Skin Blemish Control Gel, £12,

A trio of deeply exfoliating salicylic acid, skin-refining niacinamide and oil-neutralizing zinc make this our pick of all spot treatments. It zaps redness and brings inflammation down in a matter of minutes.

Main image: Bernard Osei