Why you should be putting acid on your face in 2018.

Acid. Even the word itself is scary.

Which makes the next sentence I’m about to say sound even more confronting.

If there’s just one change you make in 2018, make it putting acid on your face.

I am, of course, talking about your skincare regimen. And you’d be a fool not to. Using acids is probably the easiest way to get noticeably better skin fast. We’re talking the glow of someone who regularly gets eight hours sleep, doesn’t forget to take their makeup off and eats more green vegetables than just the solitary pickle in their Maccas cheeseburger.

Yep, all this simply by swapping from physical exfoliation to chemical exfoliation. Both help get rid of dead skin on your face, but in very different ways.

You what now?

Physical exfoliation typically uses grains (and formerly microbeads) to slough away the layers of old and dead skin. The motion of rubbing them into the skin may make you feel like you're doing a good job but it can actually be harsher on the skin and cause microtears and irritation.

While it may sound like the opposite, chemical exfoliation is not only more effective but also gentler on the skin. This method of exfoliation uses chemicals - namely - acids to remove dead skin cells which smooths and brightens skin. It also means all those other creams and gels you're applying to your face can actually get in and do their job. It's a no-brainer.

But what makes it work?

One of the most common or best entry level acid is Alpha Hydroxy Acid or AHAs. They should obviously be used with care, but aren't anything to be afraid of.

"Alpha hydroxy acids are a group of natural acids found in foods. Alpha hydroxy acids include citric acid (found in citrus fruits), glycolic acid (found in sugar cane), lactic acid (found in sour milk), malic acid (found in apples), tartaric acid (found in grapes), and others," explains Australian Skin ClinicsNational Training Manager, Darlene O'Gara.

"When applied to the skin, AHAs work by removing the top layers of dead skin cells. They can also increase the thickness of deeper layers of skin, promoting firmness." (See our favourites in the gallery below.)

Glycolic acid is the most commonly found AHA due to its ability to penetrate the skin quicker and easier, but lactic acid is also great if you need something gentler.

If you have oily, acne-prone skin or regularly get blackheads, then BHAs (Beta Hydroxy Acids) are a better option. They can get deeper into the skin and pores and also have antibacterial and anti-inflammatory properties.

Of course if you have sensitive skin, you should always patch test before overall use.

The Ordinary's Lactic Acid, $12.70, is a great starter and very budget friendly, while Paula's Choice Skin Perfecting Gel, $38, is another good option for beginners. I love Alpha H's Liquid Gold, $60, and highly rate the Nip and Fab Glycolic Fix Daily Cleansing Pads, $34.99, for ease of use. If you're willing to splash some cash, Drunk Elephant's TLC Serum, $132, combines BHAs and AHAs and is a new cult favourite amongst beauty editors.

So when should I use them?

AHA skin care products are best used in the evening after you've removed your makeup and cleansed your skin but before you apply your moisturiser. Night is better than morning because the acid can make your skin more sensitive to the sun (read: sunburn). The sensitivity can last a few days so you should really be using SPF anyway.

The general recommendation is to use once or twice a week when you first start and build that up to three or four max.

When you see the results, it can be tempting to use it every night or include multiple AHA products in your regimen. Don't.

"Even with the chemical exfoliants like lactic acid, you don't need that twice a day. It's about finding the right balance of cleansing and renewing the skin but not going so far that you damage the barrier," says Dr Frauke Nauser, Olay Senior Scientist.

"Read the instructions. If it says use once a week, there's a reason they're saying only use once a week. Don't use it twice a day. It's just common sense."

For more beauty tips and tricks, you can follow Brittany Stewart on Facebook and Instagram.