A Dermatology Guide: Skincare Acids

Ah, acids in skincare: the wild west! If you've spent any amount of time wandering the aisles at a beauty store or even scrolling down the skincare section on your favourite online shopping site, then names like hyaluronic acid, glycolic acid, salicylic acid, and ascorbic acid must get thrown around.

They all promise glowing, youthful skin, but how do you know which one to pick? Should you go ahead and slather them all on, or would that just guarantee a "face meltdown"?

There's a lot of confusion around the acid overload in skincare. Let's break it down: what do these acids do, and what skin types do they work best with?

Hyaluronic Acid

Alright, let’s start with one of my absolute favourites, hyaluronic acid! This one’s a total hydration superhero for your skin. Think of it like a big, refreshing drink of water for your face. Hyaluronic acid is a humectant, meaning it grabs moisture from the air and locks it right into your skin. It’s like your skin's personal water reservoir, keeping it plump, smooth, and oh-so-hydrated. Every time you use it, it’s like giving your skin a nice, big gulp of water, how amazing is that?

• Humectant: A molecule that attracts and binds water molecules from the environment to the skin's surface.

• Molecular weight: High-molecular-weight hyaluronic acid forms a protective barrier on the skin, while low-molecular-weight penetrates deeper for enhanced hydration.

• Increases skin hydration and plumpness by enhancing water retention in the extracellular matrix.

• Reduces transepidermal water loss (TEWL), helping to maintain skin moisture levels.

Ascorbic Acid (Vitamin C)

Now, if you're after that radiant, glowing skin, ascorbic acid, better known as Vitamin C is your go-to! This little powerhouse is an antioxidant that fights off those sneaky free radicals (you know, the ones that speed up aging and cause damage). It works wonders for brightening up the complexion, fading dark spots, and helping your skin produce more collagen. It’s like sunshine in a bottle (but don’t worry, no UV rays here!)—just pure glowiness.

• Antioxidant: Neutralizes free radicals (reactive oxygen species) that damage cells and accelerate the aging process.

• Enhances collagen synthesis by stabilizing the enzyme prolyl hydroxylase, which is essential for collagen formation.

• Inhibits tyrosinase activity, reducing melanin production and lightening hyperpigmentation.

• Reduces photoaging and promotes skin brightening by protecting the dermis from UV-induced damage.

Glycolic Acid

Let’s move on to glycolic acid, a beloved AHA that’s all about exfoliating and refreshing your skin. It’s derived from sugarcane, and it’s basically a sloughing superstar, helping your skin shed those tired, dead cells. By doing that, it makes room for fresh, smoother skin underneath. It’s like an at-home facial that helps with fine lines, wrinkles, and pigmentation. Imagine the glow after just one use.

• Alpha Hydroxy Acid (AHA): Water-soluble compound derived from sugarcane, works by breaking down the bonds between corneocytes (dead skin cells) on the outer layer of the epidermis.

• Increases skin turnover rate by promoting exfoliation, leading to smoother, fresher skin.

• Reduces fine lines and wrinkles by stimulating epidermal regeneration.

• Improves skin texture and reduces hyperpigmentation through enhanced cell turnover.

Salicylic Acid

If acne has ever been a concern, you’ve probably met salicylic acid. This BHA is your deep-cleaning best friend. Unlike other acids, it’s oil-soluble, which means it can get right into those pores to clear out all the gunk that causes blackheads and pimples. It's a total lifesaver for keeping your skin clear and calm, especially because it’s also anti-inflammatory. Think of it as your skin’s personal detox treatment!

• Beta Hydroxy Acid (BHA): Oil-soluble, enabling deeper penetration into the pore lining to dissolve excess sebum and keratinocytes.

• Anti-inflammatory properties: Inhibits cyclooxygenase-2 (COX-2), which reduces redness and irritation.

• Comedolytic action: Clears pores by breaking down the build-up of keratin and sebum, preventing the formation of comedones (blackheads and whiteheads).

• Acne treatment: Reduces acne lesions by regulating sebaceous gland activity.

Lactic Acid

Next up is lactic acid, another AHA but much gentler than glycolic acid. It comes from milk, so it’s like a creamy, soothing exfoliator that’s perfect for anyone with sensitive skin. It works just like glycolic acid to loosen up dead skin, but it’s kinder and more hydrating, too! It’s like a two-for-one deal: a mild exfoliator AND a hydrating boost. Perfect for those days when your skin needs a little extra TLC, don’t you think?

• Alpha Hydroxy Acid (AHA): Derived from milk, it promotes exfoliation by loosening the intercellular lipids that bind dead skin cells together.

• Milder exfoliation compared to other AHAs, making it more suitable for sensitive skin types.

• Humectant properties: Increases skin hydration by drawing moisture to the outer layers of the skin.

• Improves skin texture and reduces the appearance of fine lines through gentle exfoliation.

Mandelic Acid

Now, let’s talk about mandelic acid, an AHA derived from almonds. If you’ve got acne-prone skin but are a little sensitive, this is your new bestie. Mandelic acid is one of the larger AHAs, so it’s absorbed more slowly, which means it’s less likely to cause irritation. It’s gentle but effective, tackling acne, improving texture, and fading pigmentation. Plus, it helps boost collagen for firmer skin. It's a gentle yet powerful multitasker!

• Larger molecular size: Slower absorption rate leads to gentler exfoliation with reduced irritation.

• Anti-inflammatory: Helps reduce redness and swelling associated with acne and sensitive skin.

• Stimulates collagen production: Enhances skin elasticity and helps reduce the appearance of fine lines and wrinkles.

• Effective for treating acne, hyperpigmentation, and improving skin texture.

Ferulic Acid

Now here’s the unsung hero of skincare, ferulic acid. It doesn’t steal the spotlight, but it’s the quiet worker in the background, making everything else work better. Ferulic acid is an antioxidant that works wonders alongside Vitamin C and Vitamin E, boosting their effectiveness and protecting your skin from environmental stressors like pollution and UV damage. It’s like giving your antioxidants a shot of espresso. So if you love your Vitamin C, this is a must-have sidekick!

• Antioxidant: Stabilizes and enhances the activity of other antioxidants, particularly Vitamin C and Vitamin E, improving their effectiveness in protecting the skin from oxidative stress.

• Absorbs UV radiation: Acts as a shield against environmental pollutants and UV radiation, protecting skin from photoaging.

• Enhances the stability of Vitamin C formulations, leading to longer-lasting and more effective brightening effects.

• Anti-inflammatory: Reduces oxidative stress, preventing skin damage caused by pollution and UV exposure.

Kojic Acid

If you're dealing with dark spots or pigmentation, kojic acid is a game-changer. It’s derived from fungi, like Japanese sake, and it’s fantastic at evening out skin tone. Kojic acid works by blocking an enzyme that produces melanin, which is responsible for skin pigmentation. So, if you have those pesky sun spots or melasma, kojic acid helps lighten them up and give your skin a more uniform tone. It’s a gentle way to tackle stubborn spots!

• Inhibits tyrosinase activity: Prevents the formation of melanin by blocking the enzymatic process of melanogenesis.

• Skin lightening: Reduces hyperpigmentation, including sun spots, melasma, and age spots.

• Derived from fungi (e.g., Japanese sake), it effectively diminishes uneven skin tone and dark spots over time.

Azelaic Acid

Last but certainly not least, let’s chat about azelaic acid. It’s one of those hidden gems that does it all. It’s sourced from grains like barley, wheat, and rye and is fantastic for treating acne, rosacea, and hyperpigmentation. It has antibacterial properties that target acne-causing bacteria, while also reducing redness (a major plus for anyone with rosacea). Plus, it helps lighten those dark spots left behind by pimples, goodbye, post-acne marks! It’s like a little miracle worker, all packed into one.

• Dicarboxylic acid: Exhibits anti-inflammatory, antibacterial, and keratolytic properties, making it a powerful treatment for acne, rosacea, and pigmentation issues.

• Reduces keratinocyte hyperproliferation: Helps prevent the clogging of pores, reducing acne breakouts.

• Bactericidal properties: Targets Propionibacterium acnes, the bacteria responsible for acne.

• Reduces redness and inflammation, making it effective for treating rosacea and post-inflammatory hyperpigmentation (PIH).

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Choosing the Right Acid for Your Skin Type

As you may see, each of them is powerful in its own way and has certain benefits for your skin, whether it is dry, oily, or sensitive. Here's a fast breakdown of which acids are best for you:

Skin Type	Recommended Acids	Benefits
Dry Skin	Hyaluronic Acid and Lactic Acid	Hyaluronic acid provides hydration, while lactic acid gently exfoliates the skin.
Oily Skin	Salicylic Acid and Glycolic Acid	Salicylic acid unclogs pores, and glycolic acid helps reduce oil production and resurfaces the skin.
Sensitive Skin	Lactic Acid, Hyaluronic Acid, and Mandelic Acid	Lactic acid exfoliates gently, hyaluronic acid hydrates, and mandelic acid helps with acne and hyperpigmentation.
Aging Skin	Ascorbic Acid (Vitamin C) and Glycolic Acid	Vitamin C lightens and boosts collagen, while glycolic acid targets fine lines and promotes skin rejuvenation.
Acne-Prone Skin	Salicylic Acid and Mandelic Acid	Salicylic acid cleanses deep pores, and mandelic acid is gentle yet effective for sensitive skin with acne.

Final Thoughts

Now that you know what these acids can do for you, you might be tempted to slather them on thick. But don't! Overusing these skin acids does nothing but irritate your skin barrier.

The secret to making acids work for you is starting slow, incorporating one ingredient at a time, and always listening to your skin. But no matter what acid you're using, remember: wear sunscreen. Acids can make your skin more sensitive to the sun, and the last thing you want is to undo all your hard work by exposing your skin to UV damage.

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