In this post I’ll discuss lactic acid vs retinol, and which is best for anti-ageing and and treating acne. We’ll go deep into the benefits of lactic acid, retinoids, and what sort of side effects you can expect from each. You should feel clear on which is most beneficial for acne-prone skin, mature skin and how to use them in your skincare routine.
What are chemical exfoliants?
There are two kinds of exfoliation: chemical and manual. Lactic acid is a form of chemical exfoliant, which is basically a way to exfoliate your skin without using manual force. Examples of manual exfoliation include using a scrub, a facial cleansing brush or an exfoliating mitt.
The most common type of chemical exfoliation is to use an acid, such as lactic acid. But there are many kinds of exfoliating acids, and they are all quite different. Chemical exfoliants eat away at the ‘glue’ between dead skin cells, almost dissolving them. You won’t see anything happen to the eye, but you will notice more more glowy skin the next day.
We usually categorise chemical exfoliants into two main types:
Alpha-hydroxy acids
Alpha hydroxy acids are also known as AHAs for short. You might see a skincare product that says it exfoliates with ‘AHAs’, for example. There are a few kinds of AHAs:
- Lactic acid
- Malic acid
- Glycolic acid
- Mandelic acid
- A few more, less common acids like: citric acid, tartaric acid
Alpha hydroxy acids work by exfoliating the outer-most layers of skin, almost like polishing it. You should see reduced skin texture, relief from dull skin and they can also help to improve uneven skin tone in just a few uses.
Beta hydroxy acids
The most common example of a beta-hydroxy acid is salicylic acid, it’s by far the most popular BHA you’ll see in skincare products. Salicylic acid is usually derived from tree barks such as willow tree and birch.
It is especially great for oily skin as, unlike AHAs, it is oil soluble. AHAs are only water soluble, meaning they can’t get past your skin’s sebum and into the pore. BHAs, being oil soluble, can really get into the pore to break up clogged pores more effectively. The only downside I’ve noticed is that they often are too drying for dry skin. Personally my skin just never stops flaking when I use BHA, so it isn’t my favourite for clogged pores.
This isn’t to say that sensitive skin types can’t use salicylic acid, it’s more a case of trial and error. You’ll just have to see if it works for you with a patch test.
Lactic acid vs salicylic acid
To compare lactic acid vs retinol, we first need to understand what lactic acid is, where it comes from and where it can deliver best results.
Traditionally lactic acid was derived from milk, hence the name ‘lactic’, but most lactic acid products nowadays are more likely to use synthetic (man made) lactic acid. If you compare glycolic acid vs lactic acid, lactic acid is known to come with less potential irritation. We’ll get into the side effects of acids later on, but for now it’s important to know that an overuse of acids, even gentle ones, can cause skin irritation.
The reason lactic acid is typically less irritating than glycolic, is because the molecule size is much larger in lactic acid. This means it can’t penetrate as deeply, and therefore works more on the surface of the skin.
Skin benefits of lactic acid
With continued use of lactic acid, you should notice a few benefits. They can help with a wide range of skin concerns:
- Acne. Although lactic acid can help with acne, I wouldn’t say it’s one of the best active ingredients about for it
- Age spots, dark spots and sun damage. Since AHAs mostly exfoliate the surface of the skin, it can help to even out skin tone and reduce dark marks from sun damage
- Acne marks like PIE and PIH. Both of these can be helped with lactic acid, due to it skin brightening effect
- Reduced appearance of fine lines. As AHA is a natural humectant, it can reduce the appearance of fine lines temporarily as it draws water into the skin
How does retinol work?
Lots of people believe that retinol is a chemical exfoliant, too, but it actually works in a totally different way. It is not classed as an exfoliant and instead works by increasing skin cell turnover. The older we get, the slower our skin renews, and retinoids increase the rate at which our skin cells renew at the cellular level. This means that fine lines can sometimes be totally reversed, our skin looks plumper and acne is purged from the skin and replaced with ‘new’ skin. It’s one of the most powerful ingredients around.
There are lots of different forms of retinoids, ‘retinoid’ being the category term to group them all together. You might see any of these forms present in a skincare product:
- Retinyl palmitate
- Granactive retinoid
- Retinyl esters
- Tretinoin
- Retinaldehyde
- Differin/adapalene
Retinoids are basically all different strengths of retinoic acid or vitamin A, same thing. When these forms are applied to the skin, they all require ‘steps’ taken to convert to retinoic acid. Higher concentrations like tretinoin don’t require any steps, and are therefore a little more irritating. Weaker forms of retinoids, such as retinyl esters, require a lot more steps to convert to retinoic acid on the skin. These extra steps makes them less irritating on the whole.
Retinoids: the gold standard for acne and anti-ageing
If you’ve been following me on social media for a while, you’ll know that I adore retinoids. Both because of the results they’ve given me, but also because of how well studied their benefits are. They are truly considered the gold standard for anti-ageing and acne amongst dermatologists.
It’s a common misconception that retinoids are only for anti-ageing and mature skin, but they were actually first created as an anti-acne drug. I will often get asked on TikTok what teens should use for their acne because they believe retinoids aren’t suitable. In reality, retinoids are exactly what doctors and dermatologists give teenagers to treat acne.
Benefits of retinoids
Aside from treating acne, retinoids treat a lot of other skin concerns, too:
- Fine lines and the appearance of wrinkles. Retinoids boost collagen production, so you might notice bouncier skin after a good few months of use.
- Closed comedones. Those stubborn flesh coloured bumps that never seem to go away can be completely eradicated by a few weeks of use with a retinoid.
- Sun spots. Retinoids are great for evening out skin tone and texture, including age spots. Just make sure to wear SPF.
- Healthy skin. Retinoids actually ‘train‘ the skin cells to shed and renew properly, almost as if they’re resetting them to ‘normal’ function
Frequency of use: lactic acid
If you’re interested in using lactic acid but you’re not sure how often to use it, let’s get into it.
Lactic acid is generally quite gentle, and some people use it every day without issue. How irritated you get depends on a lot of factors:
- How sensitive your skin is
- Whether you live in a cold, dry or humid climate
- Which other active ingredients you’re using in your routine. For example, are you also using retinoids and vitamin C? This will make your skin a little more fragile
- How often you cleanse your face
- How drying or exfoliating your cleansers are
- How often you exfoliate in general
I would recommend using it a maximum 1-2x per week personally, and you need to truly see it as an exfoliation. That means no other kinds of exfoliation! Others will say you can, but I think it’s unnecessary and there are certainly downsides to over exfoliating, such as damaging your skin barrier. If you’ve damaged your skin barrier and are wondering how to repair it, you can check out my barrier health skincare products for clog prone skin.
If you have sensitive skin, you could also consider a method called short contact time. This is where you apply the lactic acid, wait 15-20 minutes then wash it off. It can help sensitive skins get the benefits of AHAs without the irritation.
Frequency of use: retinoids and retinol
How often to use a retinoid is a little bit more complicated. If you’re wondering how to use a retinoid to get rid of clogged pores, I recommend checking out my guide.
When you first start using a retinoid, you should start very slowly. Unfortunately a lot of the advice from GPs in the UK (PCPs if you’re in the US) is to use your retinoid every single day from the start. This is probably going to land you in some trouble! Trouble meaning painfully dry skin, red skin, skin flaking, itchiness and burning – yum! I recommend starting much more slowly to allow your skin to adjust. Here’s the schedule I usually recommend:
Month 1: apply 1-2x per week
Month 2: apply 2-3x per week
Month 3: apply 3-4x per week
By month three, you’ll have a much better feeling for how your skin tolerates the retinoid so will be able to scale it up or down yourself. Even if you’re using lower concentrations, don’t be fooled into thinking it’s ‘weak’ so therefore not irritating – yes it is.
Misinformation about retinoids
There’s a lot of misinformation about retinoids going around these days, so I thought I’d list out some of the ones I see most commonly, so you can understand them better.
Myth #1 – you need to work up to using it every day
No you don’t. There are many different ways to use a retinoid. You don’t need to work up to using it every day, you just need to use it consistently for a long time. I’ve gone through phases of using my retinoid 5-6x a week (too much for me) and 2-3x a week only. You only have to use it as often as you need it, with a minimum of 1-2 or 2-3x per week.
Myth #2 – you should work up to a stronger strength
Again, you don’t need to constantly move up in strengths. The aim of using a retinoid is to clear your skin and reasonably prevent premature ageing. If you’re using a ‘weak’ retinoid and you’re happy with the results, you don’t have to move up at all, you can just stay where you are. If you’ve been using a retinoid for 5-6 months and aren’t happy with the results, that’s when you should consider moving up.
Myth #3 – retinoids cause sun sensitivity
While it is true that your skin becomes overall more sensitive when using a retinoid, people confuse this with being sensitive to the sun whilst wearing a retinoid. This is false. Your skin becomes more sensitive at all times to the sun, not just when the retinoid is worn.
Myth #4 – you can get a safe tan whilst using a retinoid
There is no such thing as a safe tan, all tan is sun damage to a degree. If you’re using a retinoid, you especially shouldn’t be tanning your face!
Lactic acid vs retinol: which is best?
All in all, it is quite hard to compare these two products as they are quite different skincare ingredients. I think they are compared a lot because of the misconception that retinol is an exfoliant, when it isn’t.
Overall, if you’re not dealing with acne and instead are looking for brighter skin free of dull, dead cells, then I think lactic acid might be just right for you. It can be a nice alternative to Vitamin C or l-ascorbic acid if you find that irritating.
However, if you’re looking for long term reduction of acne or a powerful anti-ageing skin care routine, then retinoids are a much better option. Retinoids should make a significant improvement to both of these after 6+ months, whereas lactic acid works much faster but delivers less groundbreaking results (in my opinion).
Of course with both options… make sure you wear SPF!
