What are the benefits of AHA?Updated a year ago
They exfoliate in a very unique way, which allows them to smooth the skin, reduce wrinkle severity, improve skin moisturization, and optimize skin cell function.
Thorough and precise exfoliation
The coolest thing about AHAs is that they exfoliate dead skin cells and ONLY dead skin cells. Glycolic and lactic acids work by loosening the connectivity of the dead skin cells at the very top of the stratum corneum.
They help those dead skin cells shed on their own in an even and comprehensive way, meaning that your entire face gets equal treatment.
And why would you want to exfoliate? There’s no better way to speed up skin renewal than by letting go of the old. This is particularly true if you’d like to fade any visible imperfections, but it also helps with nearly every other concern imaginable.
They're Gentle
The secret to AHA’s gentleness is its preciseness. Unlike physical scrubs that scratch the skin in irregular patterns, AHAs tell dead skin cells to shed on their own, in a much more natural and skin-preserving process.
A well-formulated, low-percentage AHA product will only target old, haggard, and unhelpful dead skin cells. After all, the purpose of exfoliation is to remove the unnecessary dead skin cells - not the entirety of the stratum corneum.
A three-week study showed that at low percentages, AHA is a gentle exfoliation method that doesn’t irritate or disrupt the skin barrier.
Supports your anti-aging efforts
If anti-aging is your goal, your skincare routine should prioritize increasing the skin cell turnover rate. That’s the rate at which skin cells regenerate, and it’s fundamental to encouraging better production of the proteins that keep the skin looking firm.
The gold standard ingredient for encouraging skin cell turnover is retinol (especially in its enzyme-activated form, retinal), but AHAs pull their weight too. Research shows that both glycolic and lactic acid can improve collagen production, to rejuvenate and reverse signs of photodamage. Pair them with retinol and the results are even more impressive, although as Dr. Anna Chacon reminds us, it’s important to do so carefully to avoid irritaiton. At the beginning, we recommend using them on alternating nights to see how your skin responds.
Hydrate directly
We’re kind of obsessed with water. Keeping the epidermis hydrated maintains the integrity of the skin barrier. It also keeps the skin looking and feeling great - no one likes that tight, dull feeling when the skin is dehydrated!
People often worry that chemical exfoliants will increase TEWL (transepidermal water loss). But they don’t!
Both glycolic and lactic acid are humectants, meaning that they’re able to deliver water to the epidermis very directly.
Sodium lactate, the neutralized form of lactic acid, is actually a pretty common moisturizing agent, but because it’s neutralized, it doesn't exfoliate.
By using lactic and glycolic acids, you basically get a two-in-one. As you exfoliate your skin, you also get to benefit from their water-absorbing ability… Especially if you use your AHA product in a humid setting like a steamy (but not too hot) shower.
That said, overusing AHAs or choosing formulas with more than 10% could potentially damage the skin’s barrier functions, and that could lead to moisture loss. Later on, we’ll give you some tips on how to introduce AHA in a way that will preserve the integrity of your skin barrier.
Primes your skin to hold water
So we talked about short-term, direct hydration, but what about the long-term? With regular use, AHAs improve your skin’s ability to hold water.
The three-week study we mentioned above showed that even with twice daily use, glycolic acid did not increase water loss. Another study showed that over a six-week period, both lactic and glycolic acid actually managed to improve skin hydration levels.
The reason for this, we think, is pretty simple. As excess dead cells are removed, the skin is basically primed to accept and hold more water for increased hydration. Suddenly, there’s room for the fresher layers of your stratum corneum to soak up moisture and expand, not to mention that hydrating products have an easier time seeping in.
Additionally, AHAs have been found to boost the skin’s renewal mechanisms. One of the positive outcomes of that, along with increasing collagen, they also increase the skin’s natural levels of hyaluronic acid, the ultimate humectant and rejuvenating agent.
It’s ironic: Proper chemical exfoliation increases skin hydration, while aggressive physical exfoliation actually decreases it.