Dermatologist-approved, retinol and its siblings in the vitamin A family are among the most effective anti-ageing (and spot-busting) ingredients on the block. Here’s exactly how to use them well.

When it comes to anti-ageing, retinoids (i.e. vitamin A derivatives) are among some of skincare’s most sought-after. Dermatologist approved , they’re lauded for their abilities to improve fine lines, texture and tone, with their efficacy highlighted as more than just hype. In fact, the BBC documentary The Truth About Looking Good . highlighted retinol (the most famous cosmetic retinoid) as one of the best ingredients for slowing down the ageing process.

That being said, and despite just about every skincare brand launching its own 'advanced' retinoid cream, serum or oil, perceptions veer noticeably towards the apprehensive side of the scale. Concerns surrounding peeling and redness have been particularly hard to shake, but if applied correctly and products chosen cautiously, is there any reason to continue to be scared of them?

From suitable skin types to potential side-effects and everything in between, here’s what you need to know.

How do retinoids work?

In a nutshell, they help to reset skin, normalising skin function and encouraging it to behave like its younger self. And it does it by working on skin's foundations. "Retinoids affect almost every aspect of how skin functions," explains cosmetic dermatologist  Dr Sam Bunting . "They increase cell turnover in the epidermis (the superficial layer that produces plump new skin cells and sheds them when they're old) and stimulate the production of bouncy, hydrating 'mattress substances' collagen, elastin and hyaluronic acid in the dermis, the deeper skin layer."

This means retinoids help plump out wrinkles and restore firmness, They prove valuable in preventing and fading pigmentation too. "Retinoids function as antioxidants, reducing the amount of melanin the skin produces," says Dr Bunting. They also help skin shed decrepit and discoloured cells faster, resulting in dark spots and dullness becoming less evident and skin looking more even-toned.

What are the different types of retinoids?

Retinoids

The name given to the whole family of vitamin A derivatives.

Retinoic acid, commonly known as retin-A or Tretinoin

A prescription-only retinoid. “It’s the most effective anti-ageing ingredient we know, and it prevents and treats acne as a brilliant additional benefit,” says Dr Bunting.

Retinol

An over-the-counter retinoid that’s less potent than retinoic acid. “Retinol must first be converted to retinaldehyde and then to retinoic acid by a dedicated metabolic pathway within the skin in order to be effective,” says consultant dermatologist Dr Justine Kluk. “This process of 'unpacking' the actual active molecule requires a series of steps, thus retinol is considered to be less potent and fast-acting than retinoic acid [as we'll see later, that's not always a bad thing] and higher concentrations must be used in order to achieve similar results.”

Retinaldehyde or Retinal

A step up from retinol. Unlike retinol, it takes only one step for the skin to convert it into retinoic acid, so it can get to work faster (11 times faster, is the consensus), while proving no more irritating. it's also anti-bacterial, making it a very good retinoid to tackle acneic skin. Retinal can be quite unstable though, so it's hard to formulate with and that's why it's taken a long time for it to become widely available in skincare. Recently, we've seen it pop up more and more, which is a Good Thing.

Retinyl retinoate

A hybrid molecule made by fusing retinol and retinoic acid, this is, somewhat inexplicably, one of the most potent yet least irritating retinoids. Proven to be eight times more effective at speeding up collagen production than retinol, it can also, uniquely, be used in the daytime as it's stable in UV light, unlike other retinoids. A top choice for sensitive skin and for combating signs of ageing and sun damage, the molecule is patented by Medik8 (although Verso does a similar version -  Verso Night Cream with Retinol 8 , £80), making it quite expensive.

Granactive retinol or hydroxypinacolone retinoate

A so-called retinoic acid ester, this binds directly to the retinol receptors in the skin without having to convert into retinoic acid. This means, says the manufacturer of the ingredient, that it's "as effective as retinoic acid, but without the irritation". Some independent studies show it has good potential as a collagen booster, but this relative newbie doesn't enjoy the reams of long-term, independent proof that retinol and other retinoids boast. It's certainly much gentler than retinol, so a good option for reactive skins.

Retinyl palmitate

A weaker retinoid that’s a combination of retinol and palmitic acid (a fatty acid). It’s very unlikely to irritate, but it's more of a sustained skin-health ingredient than a really transformative one. Whereas the word 'retinol' on an ingredient list should give those with sensitive skin pause for thought and consider the formulation (more on that later), retinyl palmitate can safely be used by anyone at any age as an essential skin vitamin and antioxidant; you will often see it included in formulas to support the activity of other performance ingredients such as vitamin C , glycolic acid and hyaluronic acid.

It will help keep skin looking its best when used consistently but it's a very large molecule that doesn't easily penetrate the skin, so it won't dramatically fade lines and blotches unless it's used in very high doses. At which point the irritation potential goes up and you may as well opt for retinol or another more efficient retinoid.

Retinyl propionate

Like retinyl palmitate, this is a vitamin A ester or fatty acid, made by fusing retinol and propionic acid. It requires numerous steps to convert into retinol so, again like retinyl palmitate, is often called a 'pro-retinol' (retinol precursor) with low irritation potential. Unlike retinyl palmitate, the molecule is small and penetrates well, resulting in some promising studies that show it does a good job and smoothing skin and tackling pigmentation, especially when combined with other retinoids.

MORE GLOSS: Why you should add retinol to your body care routine

When should you use retinol and why?

"Our fibroblasts start to slow down in our late 20s, so it's a good idea to add in a retinoid and sunscreen as a first anti-ageing manoeuvre while skin is still basically in great shape," recommends Dr Bunting. "And if you're blemish-prone, this is an even more compelling strategy." Although, if you're a 20-something whippersnapper, there is no need to go all-out with high-strength retinoids and risk ageing irritation. This is the perfect time to benefit from introducing consistent, moderate amounts of vitamin A in the shape of formulas with good doses of retinyl palmitate or picolinate or a starter dose of retinol: that means less than 0.1% (more about retinoid percentages later).

In terms of the time of day, they would best sit in your skincare regime, save (most of) them for the evening. “Always use them at night,” advises Dr Bunting. “UV radiation breaks most retinoids down, rendering them ineffective.” As we've seen, retinyl retinoate is exempt from this rule, as is retinyl palmitate.

Which skin types suit retinoids best?

Surprisingly, the vast majority. “They suit most skin types,” advises Dr Bunting, “But they should be avoided in pregnancy and when nursing.” Certain retinoids, as we've seen, suit specific skin types better.  There's more detail on this below.

How should you start using retinol?

With caution initially, unless you're talking retinyl palmitate. “Start slow,” recommends Dr Bunting. “Apply a pea-sized amount every third night and build up to using it nightly over the course of 6 weeks, as tolerated.”

Patience is key, so don’t expect to see results overnight. “Aim to use little and often over the course of 6-12 weeks – this is a long-term project for skin health, so allow the skin to adapt over a sensible period of time,” points out Dr Bunting.

The instructions of many products will advise wearing a high SPF during the day when you use a potent retinoid at night, and for just cause. "Retinoids are in fact protective against UV rays because of their antioxidant properties  - but they decrease the threshold for sunburn and if the skin is irritated from retinoid use, this might also make it more susceptible," explains Dr Bunting. "For these reasons, it's important to use a proper sunscreen all year round."

If you’re particularly concerned if you have sensitive skin , Dr Bunting recommends a layered and low potency approach: “Use a lower potency product if the skin is sensitive and try applying over moisturiser after 20 minutes, rather than directly onto cleansed skin, to reduce irritancy,” she advises.

What retinoid percentages should I aim for?

Overall, we are not fans of starting yourself blind on percentages; the effectiveness of a product often depends on ingredients working in harmony and more is definitely not always better. But with retinoids, it is helpful to have some ballparks, as these will help you find a product that is effective as it can be for you without it causing your particular skin to flare and flake.

In general though, with the more potent cosmetic retinoids such as retinol and retinal, it's always best to buy them in a formula that speaks of a 'time-released' or 'encapsulated' retinoid. This means that the active is not dumped into the skin all at once to cause a spike of hardcore retinoic acid. You also want to see anti-inflammatory ingredients such as green tea, vitamin E and allantoin to mitigate any irritation, and if you have dry or sensitive skin, look for a formula with oils, butters or ceramides to slow down the uptake of the active ingredient.

In terms of retinol percentages, as little as 0.01% offers antioxidant protection, works as a skin-health preserver and, used consistently, can help improve lines, pigmentation and pore size. To see wrinkles, bumps and brown spots noticeably diminish, you're looking at a minimum of 0.1% retinol (ten times more than 0.01%), which is a level at which irritation may start to happen in delicate skins, in which case you need to introduce it slowly and build up. Most high street and high-end 'anti-ageing' retinols employ a percentage of 0.2 or 0.3%, which is considered tolerable for most in the right formula and offers rapid improvement. 0.5% is pretty potent and can bite if you're not careful. 1% formulas are available in Europe, but you won't find many and they can be more trouble than they're worth in terms of irritating side effects. It's most certainly not for beginners.

For retinal, 0.05% is considered a sweet spot in terms of effectiveness and stability. This is another retinoid that you want to build up, especially if your skin is reactive; Medik8's Crystal Retinal range , prices start from £47, has a 'ladder' system that you can work your way up on. Crystal Retinal 1, 3 and 6 offer 0.01, 0.03 and 0.06% of the active respectively. Medik8 Crystal Retinal 10  is 0.1% and costs £83. The professionally-prescribed Crystal Retinal 20 is 0.2%: only for advanced retinoid users and only via your skin therapist.

Retinyl retinoate's anti-ageing powers were proven at a concentration of 0.06%. Granactive retinoid shows effectiveness at 2% - that equates to 0.02% of hydroxypinacolone retinoate. Retinyl propionate shows promise at 0.3%, and retinyl palmitate has so little irritation potential that you don't really have to mind the percentage. Retinoic acid is potent at as little as 0.025% - but only professionals are allowed to determine the right level for your skin.

Are there any ingredients that shouldn’t be used with retinol or retinoids?

This is not the type of ingredient you want to experiment with in terms of layering other active serums over or under it. "Interactions with other ingredients that might inactivate many retinoids,” explains Dr Bunting. So leave the blending up to the professionals; retinol and its ilk can do very well in conjunction with ingredients such as niacinamide and vitamin C, but only if formulated synergistically by a pro in a lotion or serum. It's also worth remembering not to put the more potent retinoids on moist skin, as this can speed up penetration and cause irritation.

MORE GLOSS: The best retinol eye creams, serums and treatments

Are there any potential side effects to be aware of?

Yes. However, these can be minimised by debuting your ingredient of choice in doses. “Any ingredient that is effective will often be associated with some irritation and dryness at the beginning,” says Dr Bunting. “Aim to introduce it into a simple routine of gentle cleanser, moisturiser and sunscreen and avoid using other actives at the same time so you are only managing one variable. If in doubt, seek out an expert to help guide you on product selection and customise a skincare regime for your specific needs.” If flaking and redness persist, stop using the retinoid or switch to a gentler one; ongoing irritation is always bad for the skin.

What's the deal with 'natural retinols?'

Another piece of the retinoid puzzle that piqued our interest is the concept of ‘natural retinols’  or phyto-retinoids- a phrase used to describe ingredients such as  rosehip oil , bakuchiol , bidens pilosa (Spanish needle) and stevia. The suggestion is that they provide the benefits of the retinoids mentioned above, stimulating the production of collagen and elastin in the skin via less irritating pathways.

There are links and similarities, but it can be misleading to refer to them in this way. As consultant dermatologist at Skin55  and author of The Skincare Bible: Your No-Nonsense Guide to Great Skin  Dr Anjali Mahto explains: “Rosehip oil doesn’t contain retinol but actually contains small concentrations of all-trans retinoic acid. The main issue with this is that you don’t really know what concentration you are getting to determine whether or not it is clinically effective to produce anti-ageing effects.”

She also expresses concerns about quality variation highlights that just because the word ‘retinol’ has been added by marketeers to the name of a natural ingredient, it doesn’t mean that it has actual retinol in it (for that, you want to see the actual word 'retinol' in your INCI list) or that it has the same research retinol has. Nor is there any proof that it works in the same way or delivers the same proven results as products containing retinol.

Natural doesn’t mean that an ingredient’s less likely to cause a reaction either. “Many people feel that ‘natural’ equates to safer or gentler. However, botanicals, herbs and essential oils can cause irritation and allergies, all commonly documented in scientific literature,” says Dr Mahto. “People usually do not want to hear this but ‘natural’, in skincare, genuinely means very little.” If you’re looking to incorporate rosehip oil into your skincare regime, you might be better off doing so because of its other benefits (such as its antioxidant and essential fatty acid content), rather than its retinoid 'potential'."

Bakuchiol , on the other hand, is a botanical extract that does have some good retinol-like results behind it and it's often better tolerated than retinol, in concentrations over 0.5%. “It's the only botanical extract thus far that's shown real, clinically-proven results similar to that of retinol - stimulating collagen production, strengthening the skin's foundation, and minimising the appearance of lines and wrinkles, without the risk of irritation,” says Dimitra Davidson, President of Indeed Labs.

Many retinol creams and serums now have bakuchiol/retinol combination to give more power while minimising sensitivity. Bidens pilosa (found in Bareminerals' Ageless 10% Phyto-Retinol Night Concentrate, £52 ) and stevia (in Liz Earle's Superskin Alt-Retinol Booster, £36 ), are two even newer 'alt retinols' on the block. All are safe to use in daytime and during pregnancy whereas retinol is not.

MORE GLOSS: Best bakuchiol creams and serums 

And finally...which retinol products are worth trying?

Retinoids are lipid-soluble ingredients which means that they can be formulated in creams as well as serums and oils; your chosen texture makes no difference to the potency of the product. From the ones that carry the skin experts’ seals of approval to the newest technologies that have caught our eye, check out our edit of the best retinol creams and serums here.