The 10 best AHA skin care products (and exactly how to use them).

When the word “acid” is thrown around in the beauty world, it’s easy to conjure up images of irritated and sore skin. Yep, I was happy to give it a miss.

Then a few weeks ago, I was fed up with my skin being bleurgh. It was congested, I was getting more pimples than usual and it just looked downright dull. There was certainly no Jennifer Lopez dewy glow to see here.

On the recommendation of a friend, I tried the Alpha-H Liquid Gold exfoliating treatment, a cult product that promises to improve texture and moisture within the skin as well as decrease wrinkle depth.

Lacking that skin sparkle. Image: Supplied

I applied it, bracing myself for the blinding pain and stinging. Nothing. I waited for the bad reaction that would prove I'd made a grave mistake but instead all I felt was a bit of a tingle. For the first time in a while, my skin felt clean and smooth. The gunk was gone. After a few more uses, I started to get my sparkle back.

The magic ingredient? Alpha Hydroxy Acid or AHA. Yes, it's acid - but it's nothing to be frightened 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 Clinics National Training Manager, Darlene O'Gara.

Watch: Why face mists are a handbag essential. Post continues after video.

"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."

The AHA most commonly found is glycolic acid thanks to its ability to penetrate the skin quicker and easier, but lactic acid is also praised for being gentler. Whatever the type, they work as chemical exfoliants -  diminishing the need for vigorous scrubbing on areas that often do more harm than good.

Should I be using it?

It's a skincare fairy godmother for a range of skin types.

"They can be topically applied to the skin to commonly treat acne and improve the appearance of acne scars, photo-aged skin, and to also firm and smooth the skin. AHAs are suitable for almost all skin concerns and is a must have ingredient in your skin care," says O'Gara. (Post continues after gallery.)

While it's also great in helping to deal with pigmentation and uneven skin tone, those with sensitive skin should take care, opting for gentler formulas, always patch-testing or avoiding all together.

"You should avoid using AHA skin care products when your skin is inflamed, red and extremely sensitive," advises O'Gara.

When do I use it?

When exactly you're meant to use it is another thing that can baffle. According to O'Gara it should be done post-cleansing.

"AHA skin care products are most commonly used in the evenings after having cleansed the skin and before you apply your moisturiser. It is, however, best to follow your specific AHA product’s directions for use for the most beneficial results," she says.

Image: iStock

It's best done at night because using AHAs can make your skin more photosensitive. Apply in the morning and spend just a few minutes in the sun and you'll quickly know about it. This sensitivity lasts for a few days after application so even if you're applying at night, make sure to follow up with a product containing SPF.

How often do I use it?

When you're first starting out using AHAs it's also generally recommended to use them just two to three times a week (because these ingredients are strong and your skin can feel a little irritated if it's not used to it) before building up to more frequently or daily.

You really only need one AHA-containing product in your regimen at one time too. Yes, the visible results can make you tempted to double up but too many will just damage skin in the long term. After all, it's your largest organ - take care of it. Speak to your doctor or dermatologist if you have any concerns.

Do you use AHAs? What's your favourite product?