The Best Acids for Skin Concerns
The concept of using acid on the skin sounds scary. Acids can’t be good for the skin, right?
In reality, many acids offer remarkable benefits. When used correctly, they can visibly transform the skin — improving tone, texture, clarity, and radiance — no matter your age, skin type, or specific concern.
At Paula’s Choice Skincare, we know our skincare acids. That’s why we’ve highlighted the acids backed by strong research. Below, we break down what they are, how they work, and who they’re best for, so you can confidently choose the acids that help address your skin’s needs.
Alpha Hydroxy Acids (AHAs)
What are alpha hydroxy acids?
Alpha hydroxy acids (AHAs) are a staple in any well-rounded skincare routine. This group of exfoliating ingredients include glycolic, lactic, malic, tartaric, mandelic, and citric acids. All can help exfoliate the skin, but glycolic and lactic acids are the most researched and effective. Citric acid is generally less ideal as an AHA exfoliant because its naturally low pH makes it more irritating to the skin.
How do alpha hydroxy acids work?
When properly formulated within the right pH range, AHAs break down the “cement” that holds dead, dull skin cells to the surface. This buildup prevents natural shedding and contributes to rough texture, uneven tone, and loss of radiance. AHAs help skin shed these layers more efficiently, revealing fresher, smoother-looking skin.
Who will best benefit from alpha hydroxy acids?
All skin types can benefit from AHAs, due to their gentle nature and humectant (water-binding) properties. However, they’re best for normal to dry skin showing visible signs of sun damage.
What benefits will I see?
Regular use of AHAs reveals smoother, softer, visibly firmer, and more even-toned skin. They also reduce the appearance of sun damage, including fine lines and wrinkles.
You’ll find glycolic acid in several Paula’s Choice products, including the SKIN PERFECTING 8% AHA Lotion and RESIST Daily Smoothing Treatment 5% AHA.
Beta Hydroxy Acid (BHA or salicylic acid)
What is beta hydroxy acid?
There’s only one beta hydroxy acid used in skincare: salicylic acid. It’s a multitasking ingredient that has been relied on for decades because of how consistently and effectively it works.
How does beta hydroxy acid work?
When properly formulated within the correct pH range, BHA works similarly to AHAs to exfoliate the skin’s surface and hydrate it. However, because BHA is oil soluble (AHAs are not), it penetrates the pore lining, where it works to dissolve clogs that lead to bumps and blemishes on the skin’s surface. BHA also has a natural ability to calm the skin, so it’s preferred for those with sensitive skin types. Its gentleness makes it suitable even for rosacea or milia-prone skin.
Who is beta hydroxy acid for?
BHA can benefit all skin types, but it is especially effective for normal, oily or combination skin that has blemishes, bumps, clogged pores, overly sensitive skin, or post-acne marks.
What benefits will I see?
Daily use of salicylic acid can help refine the look of pores, smooth bumps and clogs, soften the appearance of wrinkles, and improve skin tone, hydration, and texture — all while restoring a healthy-looking glow. It truly earns its reputation as a multitasking ingredient.
You’ll find salicylic acid in several Paula’s Choice products, including our best-selling SKIN PERFECTING 2% BHA Liquid Exfoliant and RESIST Advanced Pore-Refining Treatment 4% BHA as well as in our sensitive skin-focused CALM 1% BHA Sensitive Skin Exfoliant.
Hyaluronic Acid
What is hyaluronic acid?
Hyaluronic acid is a glycosaminoglycan, a vital natural substance that helps support youthful-looking skin. Over time, age and cumulative sun damage reduce the skin’s natural supply of hyaluronic acid.
How does hyaluronic acid work?
Hyaluronic acid skincare has impressive restorative abilities. It increases the skin’s moisture content, soothes skin, and helps prevent moisture loss. Remarkably, it can hold up to 1,000 times its weight in water by binding water to skin, making it an optimal hydrator for all skin types. It also functions as a skin-calming antioxidant.
Who is hyaluronic acid for?
Every skin type can benefit from hyaluronic acid, as well as from its salt form, sodium hyaluronate.
What benefits will I see?
With consistent use, you’ll notice smoother, perfectly hydrated skin plus a plumped appearance to fine lines and wrinkles — including those around the eyes.
You’ll find hyaluronic acid in many Paula’s Choice products. Some of these skincare products include our BOOST Hyaluronic Acid Booster and RESIST Ultra-Light Super Antioxidant Concentrate Serum with Hyaluronic Acid.
Ascorbic Acid
What is ascorbic acid?
Ascorbic acid is another name for pure Vitamin C, an ingredient that occurs naturally in our skin and in many foods.
How does ascorbic acid work?
Ascorbic acid is a powerhouse antioxidant that helps defend skin from environmental aggressors, including pollution. These stressors progressively weaken the skin’s surface, contributing to dullness and visible signs of ageing. Vitamin C helps counteract this damage and supports a more youthful-looking appearance.
Who is ascorbic acid for?
All skin types can benefit from ascorbic acid and its non-acidic derivatives, such as ascorbyl glucoside, tetrahexyldecyl ascorbate, and several others.
What benefits will I see?
With consistent use, ascorbic acid helps skin look smoother and firmer, while visibly improving uneven skin tone, dullness, and the appearance of wrinkles. Ongoing use keeps skin looking bright, healthy, and resilient.
You’ll find ascorbic acid in our C15 Super Booster and C5 Super Boost Moisturizer.
Amino Acids
What are amino acids?
Simply put, amino acids are the building blocks of protein. Because the skin’s surface is composed largely of proteins, amino acids are essential for keeping it strong, smooth, and healthy.
How do amino acids work?
In skincare products, amino acids act as water-binding agents; some also have antioxidant and calming properties. Since amino acids occur naturally in the skin, they’re easily recognised and work seamlessly with other beneficial ingredients.
Who are amino acids for?
Amino acids are great for all skin types, because they’re naturally present in the skin and non-irritating.
What benefits will I see?
Thanks to their ability to attract and hold moisture, amino acids — such as proline, leucine, arginine, and serine — help skin feel smoother, more hydrated, and more supple.
Retinoic Acid
What is retinoic acid?
Retinoic acid is the form of Vitamin A that the skin naturally responds to. It’s what the gold-standard anti-aging ingredient retinol converts into once applied to the skin.
How does retinoic acid work?
After retinol converts to retinoic acid, it begins “communicating” with different elements on the skin’s surface that may be functioning less efficiently. This helps encourage the skin to behave more normally, leading to steady, visible improvement over time.
Who is retinoic acid for?
Retinoic acid is ideal for those struggling with multiple signs of aging, blemishes, or general concerns about skin texture and tone. Think of it as the personal trainer for your skin — guiding it back to looking and feeling its healthiest.
What benefits will I see?
Over 40 years of established research shows that retinoic acid helps visibly increase the appearance of firmness, diminish the look of fine lines and wrinkles, significantly improve uneven skin tone, smooth and refine the surface of the skin (yes, that includes pores), and bring the look of the skin to a healthier state.
You’ll find retinol products like the RESIST Barrier Repair Advanced Moisturiser and CLINICAL 1% Retinol Treatment.
Fatty Acids
What are fatty acids?
Fatty acids are naturally occurring ingredients that are a vital part of a smooth, healthy, and vibrant skin barrier. Examples of fatty acids include oleic, palmitic, linoleic, and linolenic acids.
How do fatty acids work?
Because they are naturally present in skin, fatty acids are easily recognised and put to work immediately. They help replenish and fortify the skin’s surface, strengthening it against moisture loss and environmental stress. Many fatty acids also have soothing properties, helping skin appear calmer and less reactive.
Who are fatty acids for?
Fatty acids benefit all skin types, but they are especially valuable for dry, very dry, or sensitive skin, which requires extra barrier support and nourishment.
What benefits will I see?
You’ll see a noticeable increase in skin’s hydration, softness, and ability to bounce back from environmental stressors that would normally send skin into a troublesome tailspin.
At Paula’s Choice Skincare, some of the products that contain fatty acids include the OMEGA+ Complex Serum and RESIST Advanced Replenishing Toner.
Tranexamic Acid
What is tranexamic acid?
Tranexamic acid is a synthetic analogue (meaning similar) to the amino acid lysine. It was originally used orally for certain bleeding disorders. However, a serendipitous result was observed: people taking tranexamic acid for one problem found it also helped solve stubborn skin discolourations. Thus, research into using this ingredient topically began and has shown impressive results in tackling discolouration when used in concentrations between 2–5%.
How does tranexamic acid work?
Tranexamic acid muscles in on two pathways that, without such interference, would set the stage for the skin’s surface to see discolourations, including a patchy, mask-like discolouration known as melasma. It also has a soothing effect which helps reduce signs of redness due to environmental exposure or minor skin irritations.
Who is tranexamic acid for?
Suitable for all skin types, tranexamic acid is especially beneficial for those concerned with dark spots, lingering post-breakout marks, or melasma. Those with very sensitive skin should introduce it slowly, as with any active ingredient. It pairs particularly well with niacinamide for enhanced brightening results.
What benefits will I see?
With once or twice-daily usage of a product that contains between 2–5% tranexamic acid, you’ll see steady improvement in discolourations, including dark spots and post-breakout marks. It's even suitable for melasma-prone skin. You’ll also see a more clarified, even skin tone.
Reminder: Discolouration improvement also depends on the daily use of sunscreen for face rated SPF 30 or greater.
Tranexamic acid is one of the key ingredients in our CLINICAL Discoloration Repair Serum.
Azelaic Acid
What is azelaic acid?
Azelaic acid is a multifunctional ingredient originally derived from grains such as rye or barley, although skincare formulations typically use lab-made forms. At concentrations of 5% and above, it helps visibly reduce redness, dark spots, bumps, and uneven texture.
How does azelaic acid work?
Azelaic acid is tricky to formulate into skincare. In its pure form, it has trouble staying evenly blended throughout a formula and faces limitations when it comes to penetrating skin. However, in an optimised formula, it quickly targets factors that trigger sensitivity, blemishes, and various types of discolouration, helping restore a calmer, clearer-looking complexion.
Who is azelaic acid for?
Azelaic acid provides benefits for all skin types, but it’s best for those with blemishes, bumps, clogged pores, redness, or post-acne marks. Its mild exfoliating properties make it ideal for pairing with salicylic acid as used to address acne.
What benefits will I see?
With consistent use, azelaic acid helps soothe visible redness, fade stubborn dark spots (including post-breakout marks), refine texture, and promote a more even, radiant appearance. It also contributes antioxidant benefits that support overall skin health.
The acids described above are among the most well-researched and beneficial for the skin. However, several other acids are also worth exploring and incorporating into your routine. These include antioxidant acids such as alpha lipoic acid, ferulic acid, and ellagic acid; brightening acids like kojic acid; and glycyrrhetinic acid from liquorice, which offers soothing properties. These ingredients are generally suitable for most skin types and can be found in select face moisturizers, face serums, and face toners.
Ready to dive into different ingredient categories? We, at Paula’s Choice Skincare, will help you learn more about skincare ingredient labels and check out our range of skincare products online.
References for this Information
Clinical, Cosmetic and Investigational Dermatology, July 2024, pages 1661-1685
Healthline, March 2022, ePublication
Postepy dermatologii i alergologii, December 2023, pages 716-724
Clinical, Cosmetic and Investigational Dermatology, August 2015, pages 455-461
Amino Acids, August 2011, pages 2481-2489
Archives of Dermatological Research, February 2017, pages 275-283
