This is the third installment in my The Ordinary overview, you can find the first post here and second one here.

Talking about acids in the skincare context sounds scary, but they are among the most useful ingredients out there. Acids are generally good for exfoliation, although there are exceptions (like the hydrating hyaluronic acid) and they have other benefits, too. The Ordinary and acids have a somewhat strange relationship, as the founder isn’t a fan (as with retinoids, he thinks there are better alternatives) and initially only launched two acid serums. I assume the brand succumbed to market pressure: skincare nerds LOVE acids* and as they are the core target group of The Ordinary, they listened.

I use acids every day, usually both morning and evening. As I’ve said before, my skin likes them and isn’t easily irritated. Keep that in mind when you read the overview below.

1. Lactic Acid 10% + HA 2% (Lactic Acid 5% + HA 2%). Lactic acid products were the only ones on this list that were part of the original The Ordinary line-up. Probably because among the more widely known acids, lactic is the gentlest and also hydrates, in addition to exfoliating and brightening. It’s probably also personally my favourite acid (Sunday Riley Good Genes has it, as do my favorite exfoliating pads by Zelens) and if you have never used any, it’s not a bad place to start. The Ordinary has two formulas and I of course only own the stronger one. The 10% is still gentle, definitely not as strong (and not as effective) as Good Genes, but if you are very sensitive, go for 5%. These have a serum texture and this is where I would use them in your routine as well, not in the toner stage. Then again, if you are using this, I would skip the exfoliating toner anyway.

2. Glycolic Acid 7% Toning Solution. This is a classic exfoliating toner that contains the most common acid – the glycolic. If used continuously (day or night or both, right after cleansing), it’ll improve radiance and clarity and prepare the skin nicely for following products. In case you’re familiar with Pixi Glow Tonic, this is very similar, although a bit stronger (5% vs 7%). I have a small preference for Pixi, but keep in mind that it is probably the best (relatively) gentle glycolic toner on the market, so it’s hard to beat. And while Pixi is affordable, The Ordinary is still much cheaper.

3. Salicylic Acid 2% Solution. Of the three most popular acids, salicylic is my least favourite. This is probably because of my skin type – it’s best for oily skin and breakouts, as it can actually get into the pores and clean them out. I wouldn’t mind a bit of pore-cleaning action on occasion, as I DO get break-outs, but for some reason it doesn’t work for me. This is very likely the reason I didn’t get on with this product, it just didn’t notice any effect. I’m also not a fan of the texture – it gets almost foamy on skin, so you need to apply a tiiiiiny amount. If your skin likes salicylic acid or you have oily/problematic skin, this might still be worth trying – either as a spot treatment or as a thin layer all over the face.

4. Azelaic Acid Suspension 10%. This is a more unusual acid that should improve brightness and evenness of skin, plus work as a strong antioxidant (rather like vitamin c, then). The product is also unusual because it comes in a cream texture. When I first tried it, I didn’t like it at all, because of the silicon-y texture and matte finish. In the course of writing this post, I went back, tried it again and didn’t have any issues – possibly because it’s much warmer now and my skin is slightly oilier. I obviously haven’t used it consistently enough to report on the results, but I’ve used it several days in a row now and my skin looks great, so at least it’s not doing any harm. It might be interesting for you if you want an acid in a cream form (for example on top of a hydrating serum) or you cannot tolerate the options above. I can use this under a richer sunscreen without needing a separate moisturiser.

5. Alpha Lipoic Acid 5%. Another more unusual acid and another that I didn’t like at all initially. I almost thought my skin looked worse in the morning than it had the night before using it. According to The Ordinary, this is a very potent product that renews the skin and shouldn’t be used every day. I wouldn’t know, as I stopped using it after that first time. I have tried it twice in the last week or so and the only thing I can say is I didn’t dislike it and might give it another go – I’m still curious, as it’s supposed to be a very potent antioxidant. My problem is that I already have quite a few hard-core products for night-time use (you should use 5% lipoic acid PM only) – my retinols, peels and vitamin c – so there isn’t really room for much else. We’ll see.

6. AHA 30% + BHA 2% Peeling Solution. This strong peel combines five acids and a few other ingredients and is possibly my favourite of the bunch. First, I like the colour. Some say it looks like blood, but to me it seems a gorgeous berry shade. Second, it’s strong. As my skin is not sensitive and can take a lot of acid, I’m always on a look-out for serious percentages. You can’t go much higher than 30% in at-home peels. This works like a mask, you spread it on your face for 10 minutes, wash off and have cleaner, smoother, softer skin afterwards. This is not for beginners, but if you use acids daily and have no problem with – for example – P50, this could be for you.

No matter which acid you use, there is always one constant: you must use sunscreen. Of course, you must use sunscreen anyway, but it’s especially important with acids (and retinol and vitamin c – all the good stuff), because they will make you more sensitive to sunlight. If you don’t protect yourself, you’ll end up with more problems than you had to begin with and that’s a stupid thing to do.

*I believe we have reached peak acid among the skincare community, though. Just as the acid toners and peels are entering mainstream, the nerds are moving on.