A Guide to the Confusing World of Face Acids and Which Ones to Use

Face acids might sound intimidating at first, but they’re one of the most effective tools in modern skincare. Whether you’re fighting acne, reducing wrinkles, fading dark spots, or improving overall skin texture, there’s an acid for almost every concern. 

Here’s your ultimate guide to skincare acids explained and how to use acids in skincare.

What Are Face Acids?

When you hear the word ‘acids,’ you might imagine bubbling test tubes or dangerous chemical burns. In reality, acids in skincare are formulated at safe concentrations to provide incredible benefits for your skin. These ingredients exfoliate, brighten, hydrate and even target specific concerns like acne and pigmentation.

Skincare acids work by breaking down the ‘glue’ that holds dead skin cells together, allowing them to shed and reveal smoother, healthier skin underneath. Depending on their molecular structure, some acids work on the skin’s surface, while others penetrate deeper to address specific issues.

The Different Types of Acids for Skin

Let’s break down the most common types of face acids and their benefits.

Alpha Hydroxy Acids (AHAs)

AHAs are water-soluble acids that work on the skin’s surface to gently exfoliate and improve texture and tone. They’re great for normal to dry skin types looking to address sun damage or fine lines.

Glycolic Acid

• Source: Sugarcane. The Invity Youth Activating Cream Cleanser contains natural plant extracts that contain glycolic acid, along with citric, malic and tartaric acids, making it great for cleaning and gently exfoliating your skin.
• Benefits: Reduces fine lines1, evens skin tone, fades dark spots and increases collagen production. Often considered the best acid for acne scars.
• Note: Glycolic acid is the smallest AHA molecule, making it highly effective but potentially irritating for sensitive skin.
• Tip: Always use sunscreen, as glycolic acid increases sun sensitivity.

Lactic Acid

• Source: Milk
• Benefits: Hydrates the skin and improves texture by being a chemical exfoliant that removes dead cells on the skin. People use lactic acid for sensitive skin as it’s gentler than glycolic acid. May also help fade dark spots. Like glycolic acid, it’s one of the great acids for wrinkles.
• Tip: Great for those with sensitive or dry skin.

Mandelic Acid

• Source: Bitter almonds. The Invity Youth Activating Exfoliating Serum contains mandelic acid to help with skin renewal.
• Benefits: Treats acne3, evens pigmentation and is less irritating due to its larger molecular structure when used as an exfoliator. One of the best acids for glowing skin.
• Tip: A good option for beginners and those with darker skin tones prone to hyperpigmentation.

Citric, Malic and Tartaric Acids

• Sources: Fruits like lemons (citric) and apples (malic). The Invity Youth Activating Cream Concentrate contains citric acid and is great for improving skin elasticity and reducing the appearance of fine lines and age spots.
• Benefits: Provide mild exfoliation, brightens skin and smooths texture.

Polyhydroxy Acids (PHAs)

Polyhydroxy Acids are a type of mild chemical exfoliants that work similarly to AHAs, but with larger molecular structures, making them less irritating and better for sensitive skin. They help remove dead skin cells, hydrate, have antioxidant benefits as well as stimulate collagen production over time, reducing fine lines.

Gluconolactone

• Sources: Comes from gluconic acid (found naturally in honey, wine and fruits). The Invity Youth Activating Exfoliating Serum uses gluconolactone, providing gentle for clearer and brighter skin.
• Benefits: The most widely used PHA that removes dead skin cells without irritation, helps retain moisture in the skin, works well for those with eczema and rosacea and is a great alternative for those who find AHAs too harsh.

Lactobionic Acid

• Sources: Lactose (milk sugar)
• Benefits: Is a powerful antioxidant that fights free radicals, acts as a humectant, locking in moisture and strengthening the skin’s natural defences, smooths skin texture and calms redness and irritation.

Maltobionic Acid

• Sources: Maltrose (a sugar found in grains like barley)
• Benefits: Provides mild exfoliation, deep hydration, repairs the skin barrier, reduces the appearance of wrinkles and is great for dry, mature or sensitive skin.

Beta Hydroxy Acids (BHAs)

BHAs are oil-soluble, meaning they can penetrate deeper into pores to clear out excess oil and debris. They’re best for oily and acne-prone skin.

Salicylic Acid

• Source: Willow bark
• Benefits: Unclogs pores, reduces inflammation and treats acne2. You may also use salicylic acid for wrinkles as it reduces the appearance of fine lines, plumping the skin.
• Tip: Found in concentrations of 0.5 to 2 per cent in over-the-counter products.

Other Acids

Hyaluronic Acid

• Function: Unlike AHAs and BHAs, hyaluronic acid is a hydrating ingredient rather than an exfoliant. This is included in the Invity SuperNAD Youth Activating Facial Sheet Mask to help soothe, replenish and hydrate your skin.
• Benefits: Draws moisture to the skin and plumps fine lines. The best acid for skin hydration.
• Tip: Suitable for all skin types and often already included in your serums and moisturisers. 

Azelaic Acid

• Benefits: Reduces acne, fades post-inflammatory hyperpigmentation4 and reduces redness.
• Tip: Found in concentrations of 15–20 per cent, it’s often used as a gentler alternative to hydroquinone for brightening.

Kojic Acid

• Source: Fermentation of rice (used in sake production).
• Benefits: Fades dark spots and evens skin tone5. Great for glowing skin.
• Tip: Highly effective but can be irritating, so patch test first.

Vitamin C (Ascorbic Acid)

• Benefits: Brightens skin, fights free radicals and increases collagen production.
• Tip: Look for stabilised forms like magnesium ascorbyl phosphate in products to make sure you will actually see results.

Lesser-Known Acids

1. Ferulic Acid
• Function: Antioxidant that enhances the stability of vitamin C and E.
• Benefits: Protects against UV damage and free radicals.
2. Linoleic and Oleic Acids
• Function: Fatty acids in oils; linoleic acid suits oily skin, while oleic acid is better for dry skin.
3. Trichloroacetic Acid (TCA)
• Use: Found in professional peels for scar treatment.
• Tip: Should only be applied by professionals.

How to Add Acids into Your Skincare Routine

Using face acids correctly is key to achieving the best results without causing irritation. Follow these steps to introduce acids into your routine:

1. Cleanse: Start with a gentle, non-exfoliating cleanser to prep your skin.
2. Apply the Acid:
• Serums: Press a few drops onto your face.
• Gels/Creams: Use a small amount and follow product instructions.
3. Moisturise: Lock in hydration with a soothing moisturiser.
4. Sun Protection: Always finish with SPF in the morning, as acids increase sun sensitivity. Try the Invity Youth Activating Invisible Mineral Sunscreen, infused with the benefits of NAD! 

Dos and Don’ts of Using Acids

Dos:

• Start Slowly: Begin with lower concentrations and increase usage gradually.
• Patch Test: Apply a small amount to your inner arm or behind your ear to check for irritation.
• Alternate Acids: Use different acids at different times (e.g., salicylic acid in the morning, glycolic acid at night).

Don’ts:

• Mix Acids: Avoid layering acids like glycolic and salicylic acid simultaneously to prevent irritation.
• Pair With Retinoids: Using retinoids and acids together can cause extreme dryness and irritation. Try the Invity Youth Activating Retinoid Serum for smooth and radiant skin.
• Skip Sunscreen: Never forget SPF when using acids.

When to Consider Using Skin Acids

Skin acids can be a great addition to your routine when you’re dealing with specific concerns that aren’t being addressed by your current products. If you’re noticing persistent issues like dullness, uneven texture, clogged pores or pigmentation, adding an appropriate acid can make a significant difference. 

They’re also worth considering if you’re starting to see signs of ageing or want to maintain smooth, glowing skin. Just make sure you start slow, especially if you have sensitive skin and to be safe, speak with a dermatologist if you’re unsure which acid is right for you.

Choosing the Right Acid for Your Skin

Here’s a quick skincare acids chart for selecting the best acid based on your skin concerns:

Concern	Recommended Acids
Acne-prone skin	Salicylic, azelaic, glycolic, mandelic
Hyperpigmentation	Kojic, azelaic, glycolic, lactic, linoleic
Ageing skin	Glycolic, lactic, vitamin C, ferulic
Dry skin	Lactic, hyaluronic

Small Steps to Improving Your Skin

Face acids are a versatile and powerful addition to any skincare routine. By understanding the different acids good for skin conditions and their unique properties and benefits, you can target your skin’s specific needs effectively. Start slow, always patch test and don’t forget to use sunscreen. With consistency and patience, these acids can transform your skin for the better.

Sources

1. Clinical Dermatology (2009). Current concepts in the diagnosis and management of the cutaneous manifestations of diabetes mellitus. Clinical Dermatology, 27(5), pp. 485–494. http://doi.org/10.1016/j.clindermatol.2009.06.023.
2. Hakozaki, T., Miyamoto, K. and Schmucki, T. (2013). The effect of linoleic acid on hyperpigmentation. Skin Research and Technology, 19(4), pp. 369–376. https://doi.org/10.1111/srt.12022.
3. Clinical Dermatology (2009). Current concepts in the diagnosis and management of the cutaneous manifestations of diabetes mellitus. Clinical Dermatology, 27(5), pp. 485–494. http://doi.org/10.1016/j.clindermatol.2009.06.023.
4. Kurdykowski, S., Mine, S., and Bordet, P. (2013). UV-induced DNA damage and repair in epidermis. Dermato-Endocrinology, 5(2), pp. 223–232. https://doi.org/10.1159/000354888.
5. National Center for Biotechnology Information (2013). Mechanisms and treatments for hyperpigmentation. PubMed. http://www.ncbi.nlm.nih.gov/pubmed/24002160.
6. Nordstrom (n.d.). Types of face acids. https://www.nordstrom.com/browse/content/blog/types-of-face-acids?srsltid=AfmBOorAbwbUAgH_N5_Lan1NRX3lDsrm3IFMJzzg89txiLtfj74u9GQw.
7. Kate Kerr London (n.d.). Every type of skincare acid explained. https://www.katekerrlondon.co.uk/every-type-of-skincare-acid-explained/.