How Do Acids Work?
Most acids work to exfoliate, with the exception of hyaluronic acid. Unlike physical exfoliants, they gently dissolve dead cells that build up on the skin’s surface to reveal fresh, new cells underneath. By removing potential pore blocking debris, they also help increase the efficacy of other products which, as a result, are able to penetrate the skin’s surface more easily.
What Are AHAs?
Working on the surface of the skin, alpha hydroxy acids (AHAs) are naturally derived and break down the bonds between skin cells, as well as improve your skin’s ability to produce collagen, which results in a younger and smoother complexion. The most popular AHAs are glycolic acid – which comes from sugarcane, and the slightly gentler lactic acid – often derived from milk.
How To Incorporate Glycolic Acid Into Your Routine
Glycolic acid is a very effective chemical exfoliant and so can make skin sensitive to sunlight and more vulnerable to sun damage. Therefore, we recommend incorporating glycolic into your evening skincare routine, to allow dead skin cells to slough away overnight and reveal fresh skin come morning. The next day, be sure to follow with a hydrating serum and SPF-infused moisturiser to help protect the new, delicate skin.
For best results, look for products that contain 10% glycolic, this is suitable for daily use and will effectively target skin concerns. Use it every other night at first for the first week and steadily increase as your skin becomes more tolerant. The Ordinary Glycolic Acid 7% Toning Solution, £6.80 is a good place to start if you’re new to the ingredient.
Ingredients You Shouldn’t Use With Glycolic Acid
Because glycolic is such an effective exfoliant, avoid using any other active ingredients at the same time. “We do not recommend combining acids with products containing peptides or other strong actives,” says Prudvi Kaka, DECIEM's Chief Scientific Officer. “For example, both retinol and glycolic work to increase cell turnover so if used in conjunction, there is a high chance of over-exfoliating the skin.” Using two such ingredients together could cause skin irritation and unwanted reactions such as sensitivity, peeling and flaking. Instead, use them two-to-three days apart to avoid overloading your skin.
How To Use Lactic Acid In Your Routine
If you have sensitive skin, try lactic acid. “Made up of molecules with a slightly higher mass, lactic acid has a milder approach to exfoliation as it requires more time to bring about the same effects on the skin as acids with lower molecular weights, such as glycolic acid,” says Prudvi.
Always apply lactic acid products after cleansing, but before applying any oils or creams so it can penetrate the skin. For the best exfoliating results, look to incorporate products containing a 10% concentration. You can apply lactic acid daily, but we recommend making it part of your evening ritual, so it has time to fully absorb. Lactic acid can also increase skin’s sensitivity to the light, so always use an SPF the next day.
How To Apply Lactic Acid Products
Take care to gently pat or tap products containing lactic acid into the skin, as it has a tendency to pill or flake if handled too harshly. As we mentioned, always allow products containing lactic acid a couple of minutes to fully absorb before applying other skincare, such as an oil or moisturising cream. To avoid this and still reap lactic acids reward, try a rinse-off treatment, such as Joanna Vargas Exfoliating Mask, £60.00 or Oskia Liquid Mask Lactic Acid Micro-peel, £65.00.
What Are BHAs?
Unlike glycolic and lactic acid, BHAs (beta hydroxy acids) are oil soluble and can penetrate both the surface layer of the skin and deeper inside the pores. When applied topically to the skin, salicylic acid breaks up the bonds or ‘glue’ that cause dead skin cells to stick together and block pores and eventually cause blemishes.
How To Slot Salicylic Acid Into Your Routine
If you suffer with occasional spots, try a targeted treatment with salicylic acid that can be directly applied to the spot. Or, if you have oily, acne-prone skin then an all-over product, such as a face wash, serum or rinse-off mask may be more suitable. It may sound counterintuitive to use an oil, but one loaded with salicylic acid will offer effective treatment while calming and balancing the complexion. BHAs are most successful when combined with AHAs, as once the surface cells are cleared, it allows salicylic to really unclog pores and reduce excess sebum, which can lead to blemishes.
When To Use Salicylic Acid Products
Salicylic acid can be quite drying, so limit use to every other day or only use during certain times of your cycle if your congestion is hormonal. If you’re looking for a weekly treatment, look to The Ordinary Salicylic Acid 2% Masque, £9.90. For those with oily, acne-prone skin, try using Paula's Choice Skin Perfecting 2% BHA Liquid Exfoliant, £10.00 every other day.