Just a handy guide on how to figure out what kind of retinoid suits your skin.

If there's one skincare category that's really bloody confusing, it's the retinoids. 

Why? Because, put simply, retinoids can be a real twat – especially if you don't know how to use them properly.

While it's the most effective ingredient (apart from sunscreen) for a range of skin concerns and can benefit most people, it can also quite literally burn your face off.

But even if you do know what you're doing, it can still trash your face around. In a good way, though.

Watch: Here are 7 ways to improve your skin while sleeping. Post continues below.

That's because it takes time for your skin to adjust to this powerful ingredient. It's important to remember that retinoids are heavy-lifters – so knowing exactly what to use and when is crucial. And because no two skin types are the same, everyone is going to have a different experience with retinoids.

While you may have heard a lot about the retinoid family (we even did a full podcast episode about them), do you know where to start when it comes to picking the right potency and product?

On a recent episode of You Beauty podcast, our friend Kelly McCarren went deep into the world of retinoids to help map it all out for us.

Here, she dishes out some of her top recommendations from each retinoid category and shares her tips on which brands and formulations will work best for every skin type.

So, let's get to it. Welcome to retinoids for dummies.

What are retinoids?

Good question! In case you need a bit of a refresher/never really understood retinoids to begin with (that's why we're here!), these babies are divided into four categories.

"Anytime you hear the word 'ret-' anything, it's sitting into the categories that sit under retinoids," explained Kelly. 

Gotcha.

"There's retinol esters, retinol, retinaldehyde (also called retinal) and retinoic acid."

Still confused? Let's break them down.

What do the different retinoids do?

1. Retinol esters.

Image: Clinique; Alpha-H; Canva.

Let's kick things off with retinol esters.

"For anyone who is terrified of retinoids – which was me for so long," said Kelly, "And you've never used anything in the family and you're kind of a little bit scared, I would recommend having a think about retinol esters."

Never heard of them before? Let us (Kelly) explain.

"They're the least potent form of retinoids. It takes retinol esters three steps to convert into retinoic acid on the skin."

Meaning? It's less irritating than other types of retinoid. "It works on a very low base," added Kelly. "It's really good for first-time users or if you've got really sensitive skin because they're gentle, but still really effective."

If you're in your mid-20s and have decided to dip your toes into retinoids or have really sensitive skin, retinol esters could be the right category for you.

When it comes to the best options, Kelly said she's heard good things about Clinique Smart Clinical Repair Wrinkle Correcting Serum, $109. Very good things.

"It's mild but really effective and has a bunch of other great stuff in it," she said. "For example, it's got some peptides and some hyaluronic acid."

Another one of Kelly's recommendations? Alpha-H Liquid Gold Midnight Reboot Serum, $135.

"We all know and love Liquid Gold. This one has got a small amount of the retinoid in it, as well as 14 per cent glycolic acid. So, it's a really strong chemical exfoliator and not for the fainthearted. But it's still just that little milder than some of one per cent retinol products on the market."

Even better? It's got a bunch of other things in it, like hydrating ingredients and antioxidants, which keep nourishing your skin at the same time.

2. Retinol.

Image: ActiveSkin; Sephora; Skinstitut; Canva.

We are bumping up the intensity, friends! 

As Kelly explained, retinol promotes effective exfoliation, prevents acne, helps with pigmentation, controls oil and can smooth fine lines and wrinkles. 

Yep. All of the things.

"Most of the products you get from the pharmacy that have the word 'retinol' or 'retinoid' in it falls into this category. So it's pretty intense without being like, 'Oh my god I'm gonna have some serious issues.'"

When you start out with a retinol, though – because it is that little bit stronger than retinol ester – it can take a bit of time for your skin to get used to it. So you're going to want to work on slowly building up your tolerance.

Kelly said, "You could pop it on and then you wash it off after half an hour. Or you could put a cream on first and then you pop the retinol on after that, just so it's got some sort of buffer, or you're kind of diluting it."

If you've got more of a tolerance to the ingredients, and you've been trying it for a little while and your skin seems to be holding up just fine, you could then apply it to clean, bare skin or use it a couple of times per week. You can even move your way up to every second night.

"You honestly just need to watch how your skin reacts to these products and sort of use your judgment," said Kelly.

One of Kelly's recommendations is Skinstitut Retinol Serum, $41.30. 

"This is 0.25 per cent, so it's really really low. Is a great beginner product," said Kelly. 

"It's lightweight, corrective and would suit most skin types because it is a low-dose retinol. It's really good at repairing and strengthening the skin because it's also got peptides in it."

Next up, we have La Roche-Posay Redermic Retinol B3 Serum, $71.95. Like most of La Roche-Posay's products, it's formulated with sensitive skin in mind. 

"It's got 0.1 per cent pure retinol and two per cent retinol ester," said Kelly. "It's a gentler, more gradual working form of active ingredients. This means your skin is going to tolerate it more and you're not going to have a really intense irritation."

It also has niacinamide and glycerin in it, which help protect your skin barrier and make sure it stays strong.

Also on the list? Biossance Squalane and Retinol Night Serum, $119, which Kelly said she's been trying to get her hands on forever (it's always sold out at Sephora!).

"It's an innovative formula that uses time-release retinol and retinal (which we'll get into later). So it works really well from a skin cell turnover point of view, but then it's got squalene in it, so it's just really like delicious and nourishing."

3. Retinaldehyde.

Image: Medik8; ActiveSkin; Canva.

Also known as retinal (not to be confused with retinol) — it is the strongest over-the-counter retinoid. 

Confused yet?

"Similar to retinol, it does cause a little bit of irritation and dryness, just because it is the strongest. It only has one step to convert and become active."

As Kelly warned, "It's like definitely not for the fainthearted or someone that's easing into the category. This is for people that are well-versed in a retinol ester or retinol and are thinking of moving up but aren't ready to go down the prescription road."

Anyone with really oily skin or someone with older, less sensitive skin is best suited to retinaldehyde.

In terms of product suggestions, first up Kelly recommends Medik8 Crystal Retinal, $85.

"A lot of dermal therapists and skin clinicians swear by this, which is why I've included it," she said.

"They did some clinical studies that proved it was 11 times faster and has a higher exfoliation rate than some of the other retinals on the market. Meaning? You're going to get supercharged results in less time."

Again, this is definitely not the right choice for anyone with sensitive skin or someone who is just starting out, but it's great for those looking to upgrade.

Another one Kelly has tried and loves is the Murad Retinal Resculpt Overnight Treatment, $170. (Psst... she actually got her mum onto it too – so you know it's good!).

The formula uses an encapsulated retinal serum to help improve the look of sagging skin and wrinkles, with minimal irritation. We love to see it.

4. Retinoic acid.

"This is the most potent form of retinoid," said Kelly. "However, that means it has very strong side effects.

"If you just went in gung-ho, you could do some serious damage, and a lot of dermal clinicians and doctors and dermatologists would highly advise against it."

Read: Dryness, peeling and irritation. All of the stuff you don't want for your cute face!

You can only get the retinoic acid treatments via prescription, so make sure you speak to a health professional and suss out if it's right for you.

Which retinoid team are you on? Do you have a favourite product? Share with us in the comment section below.

Feature image: Instagram/@kelly_mccarren; Sephora; ActiveSkin; Alpha-H.