Best Vitamin C serums under £20

best vitamin C serums under £20

Vitamin C is part of the skincare ‘holy trinity’, alongside retinol and sunscreen, and it’s one of the best researched active ingredients for skin health. Here’s my guide to the best Vitamin C serums under £20 – the easiest way to get some of the good stuff into your skincare routine.

This article includes reviews of 25 reasonably-priced products, including the newest serum launch by Marks & Spencer, two companies that have recently expanded into the UK market, and a couple of Korean cult beauty treats. It also covers different types of Vitamin C, and serums for different skin types and goals.

This comprehensive look at the best cheap Vitamin C serums in the UK is divided into six main sections:

  • Why use a Vitamin C serum? – reasons & benefits
  • Ascorbic acid Vitamin C serums under £20
  • Tetrahexyldecyl Ascorbate serums under £20
  • 3-0-Ethyl Ascorbic Acid serums under £20
  • Ascorbyl glucoside serums under £20
  • Sodium ascorbyl phosphate serums under £20
  • Mixed Vitamin C serums under £20

If you’re wondering what all the fuss is about, or which type of Vitamin C is best for you, read on.

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Why use a Vitamin C serum?

There are multiple benefits to be gained from using Vitamin C serums. For starters, it’s a powerful antioxidant, protecting your skin from free radicals, helping prevent sun damage (combined with sunscreen), reducing the effects of irritation and pollution.

Vitamin C makes existing sun damage and uneven blotches of pigment less visible on the skin’s surface, including red or brown blotches left behind after spots. This contributes to a ‘brightening’ effect. Research also suggests some types of Vitamin C boost collagen levels in the skin, preventing premature ageing.

Many companies charge a fortune for their serums, and the quality doesn’t always match the price. Fortunately there are several great cheap Vitamin C serums under £20, and under £10. Changes in the beauty market in recent years have made it more affordable, even on a low budget.

How long does Vitamin C serum take to work?

The good news it that you can get an antioxidant effect to boost your sunscreen’s sun protection right from the very first time that you use it.

If you’re hoping to reduce hyperpigmentation like sun spots and post-acne marks, it takes 4-6 weeks for most skin to turn over a layer of cells. Full effects take up to 12 weeks, combined with broad spectrum high SPF sunscreen.

Collagen boosting benefits come after several weeks or months of diligent use. This effect has been mainly studied with relatively high concentrations of the ascorbic acid version of Vitamin C.

Does Vitamin C serum smell strange?

Yes, most ascorbic acid based Vitamin C serums have a natural smell, especially the C-E-ferulic ones. Some people describe it as the smell of old copper pennies. The scent fades away soon after application, but can take some getting used to.

For this reason, many beauty companies add fragrance to their products, but not everyone can tolerate perfume in their skincare. There’s a tendency to add citrus smells too, as we associate Vitamin C with oranges, but orange oil and other citrus may cause sun sensitivity. I prefer to go fragrance free, but have included some fragranced products here as many people prefer them.

Ascorbic acid Vitamin C serums under £20

Ascorbic acid, also called L-ascorbic acid, is the pure form of Vitamin C. It’s generally found in 10-20% concentrations in effective serums, and has various pros and cons.

Pros of ascorbic acid serums

  • The best researched form of Vitamin C.
  • The strongest type of Vitamin C.
  • Widest range of proven benefits for skin health.

Cons of ascorbic acid serums

  • Unstable – easily broken down by light, heat and contact with air.
  • Most people find it tingles when they start using it.
  • Can cause rashes, sensitivity and acne flare-ups.
  • Some people can’t tolerate it at all.
  • Should not be used at the same time of day as potentially irritating ingredients such as retinol/retinoids, strong AHA or BHA exfoliants etc.
  • Using ascorbic acid and niacinamide at the same time may irritate some people.

And now, on to look at some of my favourite sub-£20 ascorbic acid Vitamin C serum finds and picks. Here are the first four, and they’re also the strongest.

NEW! Dermatica Vitamin C 15%: Fresh Batch Ascorbic Acid | £15.50

Dermatica best vitamin C serums 15% ascorbic acid

A brand that makes science-led skincare, Dermatica is now offering a 15% Vitamin C serum that’s made fresh every month. You can buy it as a one-off to try it, and there’s also the option to subscribe and save 20% on the standard price.

This is a well-made, well packaged option with lots of nice extras in the formula, including glycerin, ceramides, hyaluronic acid, ferulic acid, panthenol and more. NB: you get 12.5ml per bottle, so it’s fairly small but it spreads easily and a little goes a long way.

Buy here: Dermatica

Geek & Gorgeous C-Glow 30ml | £11.95

This is my HOTTEST recent find from a company new to the UK, and in my opinion it’s a real bargain. The water-light serum contains 15% ascorbic acid, and additional antioxidants ferulic acid and Vitamin E to stabilise it and increase effectiveness. The formula is quite similar to a certain (overpriced!) cult beauty product that costs £165 a bottle, and will work in the same way. Made fresh every week.

The light texture means it can be layered under all kinds of different products, and if you keep it in the fridge it should last up to three months. The real genius move is that Geek & Gorgeous also sell an empty 10ml sized mini bottle, so you can decant a week’s worth into it and stick it in your bathroom cabinet, or travel bag. The serum shouldn’t oxidise or go off in this timeframe, plus it means you’re opening the main bottle in the fridge less frequently too.

Buy here >> Geek & Gorgeous UK

GoW Vitamin C Serum 23% + Ferulic Acid 30ml | £10.00

A very, very strong serum that contains 23% Vitamin C, ferulic acid, soothing B5 (panthenol) and hydrating hyaluronic acid. It’s fragrance free, easy to apply and suitable for vegans. I’ve used this on and off for a long time, and have to admit that it’s too strong for me on its own – I ended up mixing it half and half with a simple hydrating serum to make it less concentrated.

If you’re a very experienced user of Vitamin C you might like this one, but it’s not for newbies. It’s definitely good value for money though! Be sure to start slowly and work your way up to regular use. The packaging is in an airless pump bottle, which is excellent for helping to keep the serum ingredients fresher for longer.

Buy here >> Victoria Health

Bondi Sands Gold’N Hour Vitamin C Serum 30ml | £9.99

This serum has 10% ascorbic acid, plus gentle exfoliant caviar lime, hydrating glycerin, soothing licorice extract and antioxidant kakadu plum. It has a nice spreadable consistency and you only need two or three drops to cover the whole face.

I think it ships from Australia, which could affect freshness, so be sure to buy from a busy retailer so you don’t get old product. There have also been reports of some of their bottles being too loosely sealed, and leaking. Be sure to keep the bottle tightly closed between uses, and store it in the fridge. All in all, this is a really nice formula for under £10, and it also has no perfume in it.

Buy here >> Boots, Sephora UK

Now, on to three more ascorbic acid products, if you’re looking for other pure Vitamin C serums under £20:

The Ordinary 8% Ascorbic Acid + Alpha Arbutin 30ml | RRP £10.80

This is an anhydrous solution, i.e. made without water, so it has quite an unusual almost-oily texture which not everyone will get on with. There are only three ingredients in it: propanediol, ascorbic acid, and alpha-arbutin. Propanediol isn’t an oil, but does have moisturising properties and can leave a dewy finish on the skin.

The ascorbic acid is more stable in a waterless solution so should last longer after you open the bottle, but the 8% level is going to be slightly lower in terms of effectiveness (10% to 20% is the commonly recommended amount, but as low 5% can still work). That might be useful if you’re looking for something less strong though. Alpha arbutin helps to reduce the look of dark spots and uneven skin tone.

Buy here >> The Ordinary Beauty Bay, Cult Beauty

Purito Pure Vitamin C Serum 60ml | RRP £18.00

This Korean skincare serum contains 5% ascorbic acid, and might be a nice place to start if you’re trying this ingredient out for the first time. At this level you should get immediate antioxidant protection and a slower general brightening effect, although it’s probably not going lighten any major dark spots quickly or increase collagen. You also get a massive 60ml in the bottle, so it’s great value if you can use it all up before it naturally goes off (takes up to three months).

The light serum also contains multiple beneficial ingredients including sodium hyaluronate, anti-wrinkle adenosine, antioxidant hydroxyacetophenone and a small amount of niacinamide. It’s a good all-rounder if you like a quick routine in the mornings and want an easy one-and-done. Fragrance free and cruelty free.

Buy here >> Sephora UK, Amazon UK

The Ordinary 100% L-Ascorbic Acid Powder 20g | £5.70

I’m on the fence about mentioning do-it-yourself vitamin C products – especially ascorbic acid powder – because it’s easy to get the amounts wrong and hurt your skin. I don’t use this stuff myself, but I know other people who do, so I thought I should give you the option.

This is designed to be mixed into water-based products, mainly serums. If you know what you’re doing, and follow all the safety instructions then this product might appeal. Never mix this directly into sun protection products: messing about with SPF can destabilise the formula.

Buy here >> The Ordinary, Cult Beauty, Beauty Bay

PG tips for use

A few important things to keep in mind:

  • Only buy ascorbic acid products that are freshly made, from reputable retailers with fast turnover of stock.
  • Keep it in the fridge if you can, tightly sealed.
  • If the serum turns dark yellow or brown it’s gone off – bin it.
  • Always do a patch test and build up use slowly.
  • Wash your hands thoroughly after applying to prevent staining.
  • Wear sunscreen over it in daytime.

Tetrahexyldecyl Ascorbate Vitamin C serums under £20

Also called THD ascorbate or ascorbyl tetraisopalmitate, tetrahexyldecyl ascorbate is a more stable form of Vitamin C that’s been modified to make it lipid-soluble. Usually found in more oily, moisturising products.

Concentrations of 0.1% to 2% give general antioxidant benefits, and 5%+ is used to target hyperpigmentation. Shown to protect/increase collagen in some studies.

Here are three serums that include this ingredient:

Best THD ascorbate vitamin C serums under £20

GoW C-Deep Vitamin C Serum 30ml | £19.50

Just squeaking in under the £20 mark, this GoW serum contains 3% Tetrahexyldecyl Ascorbate. The manufacturers claim it can get deeper into the skin, increasing levels of collagen production and also hydration. It could definitely help with surface brightening at this concentration. It’s a simple product, with a moisturising squalane base and antioxidant thiotaine.

Oil-based serums can take longer to sink in, so remember that if you tend to be in a rush in the morning. As it’s in a light oil it should be applied after any water-based products such as toners, serums or gel moisturisers. Squalane is generally considered relatively non-comedogenic, so it wont block most people’s pores, but consider patch testing if you’re acne-prone. Fragrance free.

Buy here >> Victoria Health

M&S Fresh Elements Glow Radiant Overnight Serum 30ml | RRP £15.00

This is spanking new for June 2023 from the latest range at Marks & Spencer. Contains a generous 10% ascorbyl tetraisopalmitate, plus glycolic acid for exfoliation. Also has antioxidant hydroxyacetophenone and Vitamin E, and a range of moisturising oils and waxes, including squalane.

If you’re looking for surface brightening then this is likely to give you the desired result, as long as you don’t have sensitive skin (it’s strong, and it also contains fragrance). Probably not suitable for anyone prone to acne or blackheads.

Buy here >> Marks & Spencer

Oleus Vitamin C Oil 50ml | RRP £14.00

This contains 1% active ingredient, for an everyday antioxidant protective effect. One for the natural beauty fans rather than the beauty geeks. The rest of the product is pure moisturising kiwi seed oil. It’s gentle and one for drier skin types. You get a lot of product – 50ml – for a relatively low price as well.

Buy here >> Holland & Barrett

3-0-Ethyl Ascorbic Acid Vitamin C serums under £20

This more stable form of Vitamin C, also called Ethyl Ascorbic Acid, is both water-soluble and oil-soluble. Thought to give the same benefits as ascorbic acid, although there is less research. Requires a less acidic environment than pure ascorbic acid, so may cause less sensitivity.

It doesn’t need to be used in large amounts due to its stability, so it’s often found in the range of 0.5% to 5% in skincare, but some serums contain more.

I have six low priced options for you, starting with the three of the strongest:

Minimalist Vitamin C + E + Ferulic 16% 20ml | £7.99

This is the new Vitamin C serum from Minimalist, who are new-ish to the UK. I haven’t managed to try it out yet but will update this article once I do. The name is confusing: it’s 15% 3-0-ethyl ascorbic acid plus a 1% mixture of Vitamin E and ferulic acid. It looks pretty strong.

You only get 20ml in the bottle, but the price per ml is still low. Unique formula contains C60, also called Carbon 60 or fullerenes – claimed to be a powerful antioxidant / anti-ageing ingredient, but there’s very little research to back this up. Watch this space. Fragrance free.

Buy here >> Sephora UK

No7 Radiance+ 15% Vitamin C Serum 25ml | RRP £19.95

Contains a generous amount amount of Vitamin C, and has plenty of ‘slip’ which makes it easy and pleasant to apply a thin layer. This serum also has sodium hyaluronate for hydration and skin-plumping, plus soothing allantoin. You only get 25ml though, so factor that in to your budget.

It does contain perfume, and has a light orange-y fragrance, which may bother some people with sensitive skin. It’s very, very popular, and is regularly on offer at Boots.

Buy here >> Boots

Superdrug Vitamin C Super Booster 30ml | RRP £10.99

Contains 10% 3-0-ethyl ascorbic acid plus 0.1% ferulic acid and another antioxidant called hydroxyacetophenone. It’s a relatively simple serum, with the active ingredients purely focused on antioxidant action.

Don’t confuse this with Superdrug’s standard ‘Vitamin C Booster serum’ because they contain different active ingredients. Contains fragrance.

Buy here >> Superdrug

Here are the next three 3-O-Ethyl Ascorbic Acid vitamin C serums under £20:

Superdrug Optimum Vitamin C Serum 30ml | RRP £14.99

Another Superdrug 10% 3-O-Ethyl Ascorbic Acid serum, this one also contains niacinamide, Vitamin E and sodium hyaluronate, plus a number of emollient (moisturising) ingredients. It’s slightly more expensive than the serum above, but it offers a wider range of benefits and is in more robust packaging.

The Optimum range is marketed towards the mature skin age group, but can be used by anyone of any age with dry, slightly dry or normal skin. Contains fragrance.

Buy here >> Superdrug

PG Tip: Superdrug’s Optimum products are often included in special offers, and at the moment this serum is half price (£7.49).

Glow Hub The Scar Slayer Serum 30ml | RRP £14.00

The packaging is wrong in pictures because it mentions L-ascorbic acid, and this actually contains 3-0-ethyl ascorbic acid (probably due to a recent reformulation and will hopefully be corrected soon). The percentage is probably around 2% to 3% although Glow Hub are a bit coy about it.

That’s enough to have an effect though, without being too harsh. Also contains a decent amount of tranexamic acid, soothing lactobacillus ferment, and antioxidant tocopheryl acetate (Vitamin E). The formula should work for most people to target pigmentation, mild scarring and dark spots left over from breakouts. It’s fragrance free and vegan.

Buy here >> Sephora UK, ASOS

PG Tip: There’s a 15ml mini RRP £9.00 at Sephora in case you’d like a trial size to test it out.

Skin&Lab Vitamin C Brightening Serum 30ml | £18.40 approx

This light, hydrating Korean skincare serum doesn’t contain much vitamin C, but it’s still in the effective concentration range, about 1.5% (most 3-0-ethyl ascorbic acid is 0.5% – 5% in skincare).

Also contains lots and lots of other soothing, plumping and antioxidant ingredients that are beneficial to the skin. Good all-rounder ingredients list for normal, oily and combination skin types. Fragrance free and cruelty free.

Buy here >> YesStyle, Amazon UK

Ascorbyl glucoside Vitamin C serums under £20

Many serums contain ascorbyl glucoside, a water soluble derivative of ascorbic acid. A concentration of 0.5% can have antioxidant benefits, and 2% to 5%+ is needed to improve pigmentation.

Pros of ascorbyl glucoside

  • Relatively gentle, stable form of Vitamin C.
  • Can be safely combined with niacinamide.
  • Formulas don’t need to be strongly acidic to work.
  • Gets into the skin easily.

Cons of ascorbyl glucoside

  • Not as strong as ascorbic acid.
  • Not as well researched as ascorbic acid.
  • More for brightening than collagen building.

Now let’s look at three affordable and popular ascorbyl glucoside serums:

The Inkey List 15% Vitamin C + EGF Serum | £15.99

A lightweight unfragranced serum containing 15% ascorbyl glucoside and 1% plant-based Oligopeptide-1, also known as Epidermal Growth Factor. It’s a fairly gentle, non-greasy serum – I like using this during the Summer under sunscreen. Has a lovely texture and layers well with other products, making it hugely popular.

The jury is still out on the effectiveness of the peptide, but the company recommend allowing about 10 minutes for it to sink in and let the skin respond. Regularly included in offers, so watch out for those. Vegan and fragrance free.

Buy here >> Sephora UK, Cult Beauty, The Inkey List

The Ordinary Ascorbyl Glucoside Solution 12% 30ml | RRP £12.70

A popular water-based serum with one active ingredient and no other whistles and bells. It works well for brightening, and it’s gentle on the skin. Like many The Ordinary products, I find this serum a bit ‘goopy’ and thicker than I’d like it to be.

However, it is cost effective, so if the only thing your skincare routine is missing is some non-irritating Vitamin C then this might be the one for you. It generally layers well with other products if you don’t use too much and allow it to dry a little before putting anything else on top.

Buy here >> Sephora UK, CultBeauty, The Ordinary

Revolution Skincare X Sali Hughes Must-C Daily Serum 30ml | £14.99

An affordable formula with 15% ascorbyl glucoside, and lots of other supporting ingredients for everyday skin health. That includes niacinamide, Vitamin E, ferulic acid, glycerin, squalane and sodium hyaluronate.

Unfortunately this serum does contain perfume, lots of it. Revolution Beauty seem to add it so many of their products, and a significant number of people really don’t like it. It’s a deal breaker for me, but everyone’s different.

Buy here >> Boots, Superdrug

Sodium Ascorbyl Phosphate serums

Lots to choose from here, so let’s start by quickly looking at the pros and cons.

Pros of sodium ascorbyl phosphate (SAP)

  • One of the most stable forms of Vitamin C, lasts a long time in your skincare.
  • Super gentle, so a good one to try for extra-sensitive skin, or if you’re just staring out.
  • Has an anti-bacterial and anti-acne action.

Cons of sodium ascorbyl phosphate

  • It doesn’t absorb deep into the skin, and it’s mainly used for surface benefits.
  • Not as strong in its effects as ascorbic acid.

Now let’s look at the best value SAP vitamin C serums under £20:

Bubble Day Dream Tone and Texture cheap vitamin C serum

Bubble Skincare Day Dream Vitamin C + Niacinamide Serum | £18.00

This Australian brand has come up with a highly impressive serum that should work for all skin types. It contains a generous amount of SAP Vitamin C, effective concentrations of blotch-busting tranexamic acid and alpha arbutin, a little niacinamide and five different types of ceramide to support the skin barrier, humectant glycerin, and soothing/brightening licorice extract.

Talk about an all-star line up for helping skin tone and texture. It’s also vegan and cruelty free, and contains no fragrance. The packaging also protects from light and air degradation too.

Buy at: BeautyBay (exclusive to this shop in the UK)

Balance Active Formula 12% Vitamin C Supershot 30ml | RRP £8.99

This is a 12% concentration of sodium ascorbyl phosphate, which is relatively high. Balance Active claim it brightens the complexion and reduces dark spots, which is realistic. There’s also a tiny amount of lactic acid in it, which is more likely to soothe than to exfoliate.

This simple serum plays well under other skincare. Fragrance free and cruelty free.

Buy here >> Sephora UK, Amazon

Simple Booster Serum 10% Vitamin C+E+F 30ml | RRP 8.00

This is a moisturising emulsion serum with a slightly misleading name. The “10%” is actually 2% sodium ascorbyl phosphate + 1% vitamin E acetate, and “7% Vitamin F” which is not really a vitamin at all (it’s a term for two fatty acids: alpha-linolenic acid, or ALA, and linoleic acid, or LA) and comes from the hemp oil.

All that aside, it’s fragrance free, suitable for vegans, and a pretty safe bet if you have dry, very dry or normal sensitive skin. It turns up on offer regularly at Amazon, Superdrug and various supermarkets.

Buy here >> Superdrug, Amazon UK

ASDA Brightening Vitamin C Radiance Boosting Serum 50ml | RRP £2.30

Yes, you read that correctly, it’s only £2.30 full price and you get a socking great 50mls in the bottle. They don’t mention the concentration of SAP vitamin C in this, but looking at the ingredients list I’m guessing it’s more than 1%, maybe 2%. That’s likely to be an effective amount for everyday antioxidant protection, gentle skin brightening and anti-acne action.

Also contains a decent amount of hydrating glycerin, and a little skin conditioning papaya extract and antioxidant acai berry. Unfortunately also contains perfume, so may be unsuitable for sensitive skin types, but at this price it might be worth buying a bottle for yourself and patch testing it.

Buy here >> ASDA

Great value multi Vitamin C serums under £20

Some serums contain two or more different types of vitamin C, to combine their various benefits. Here are three reasonably priced ones that you might be interested in.

Healthspan Vitamin C Serum 30ml | RRP £17.95

Contains 3-0-ethyl ascorbic acid, ascorbyl tetraisopalmitate and a little sodium ascorbyl phosphate. Also has antioxidant kakadu plum, grape seed oil, ferulic acid and Vitamin E, plus sodium hyaluronate, so it’s a very nice all-rounder product. They’ve obviously put a lot of thought into the formulation, and it’s great value for money – better than several serums costing more than twice the price.

They describe the Vitamin C content as “10%” which seems to be the combined percentages of all three ingredients. The formula is lightly moisturising, so will mainly appeal to dry to normal skin types. Fragrance free, and comes in completely biodegradable sugarcane packaging.

Buy here >> Sephora UK, Amazon UK

Viola Skin Anti Ageing Vitamin C Serum 30ml | RRP £19.97

I hesitate to mention this one, but it’s insanely popular so I probably should. Why hesitate? They don’t make it easy to find the ingredients list or where they’re based (made in China, UK distributor, can’t find much about the parent company.) They also claim there’s “20%” (presumably Vitamin C?) in this product on their packaging, which sounds quite high – too high maybe – when you look at where sodium ascorbyl phosphate and possibly ascorbyl glucoside sit on the INCI list. Unless they aren’t listed in the correct order. Hmmm.

Anyway, the other ingredients include soothing aloe vera, allantoin and witchhazel, a tiny amount of jojoba oil, antioxidant Vitamin E and sodium hyaluronate. As long as you aren’t allergic to witchhazel or find that jojoba oil gives you blocked pores, this is probably going to work well for most skin types, even if it doesn’t contain as much Vitamin C as the marketing implies. Fragrance free.

Buy here >> Amazon UK

PG Tip: Regularly on sale at Amazon UK for under £10.00.

Balance Active Formula 3% Brightening Serum 30ml | RRP £4.99

This serum is a better option for combination and oily skins than the Healthspan serum mentioned earlier. Contains the Stay-C 50 version of sodium ascorbyl phosphate (around 2% or so) plus a little ascorbyl glucoside to make a 3% concentration in total. This should give antioxidant benefits, gentle brightening, and probably some anti-acne action too, all for under a fiver.

Also contains glycerin, skin conditioning and anti-wrinkle zinc PCA, tocopheryl acetate (Vitamin E) and antioxidant olive leaf extract. Contains perfume, but it’s cruelty free. Won best affordable serum in the Attractor Beauty Awards 2020, and best serum at the Global Make Up Awards 2021.

Buy here >> Savers, Amazon UK

PG Tip: Regularly discounted at places like Savers, Home Bargains and supermarkets.

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That’s it for the best Vitamin C serums under £20. Let me know if you have any questions or favourite products leave a message in the comments section below.

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