Understanding different skincare acids

When it comes to skincare, acids can be a powerful tool for achieving a multitude of skin benefits. But with so many different types of acids available, it can be hard to know which one is right for you. In this blog post, we'll take a closer look at what acids do for the skin, the different purposes of skincare acids, and how to use them safely and effectively.

What defines an acid in skincare?

An acid is a molecule with a specific chemical group at the end of it, which has a double bonded oxygen molecule to the final carbon in the molecular chain, then another oxygen bonded to a  hydrogen. The rest of the molecule can differ greatly, which explains why there are many types of acids that offer skin care benefits. 

Here are a few of the most common types:

Exfoliating skincare acids 

• Alpha hydroxy acids (AHAs): AHAs, such as glycolic acid and lactic acid, are water-soluble acids that are great for exfoliating and brightening the skin. They're particularly effective for those with dry or dehydrated skin, as they help to remove dead skin cells without stripping away too much moisture.
• Beta hydroxy acids (BHAs): BHAs, such as salicylic acid, are oil-soluble acids that are great for unclogging pores and reducing inflammation. They're particularly effective for those with oily or acne-prone skin, as they help to remove excess oil and prevent breakouts.
• Polyhydroxy acids (PHAs): PHAs, such as gluconolactone and lactobionic acid, are similar to AHAs but are gentler on the skin. They're great for those with sensitive skin, as they help to exfoliate without causing irritation.

Hydrating skincare acids 

• Hyaluronic acid: Hyaluronic acid works by binding to water molecules holding up to 1000 x its weight in water making it a highly effective hydrating ingredient that helps to keep skin hydrated and plump. It’s what we call a ‘humectant' which means it can draw water molecules towards it due to a slight molecular charge (like a magnet).
• Vitamin B5 aka pantothenic acid: This is another fantastic humectant, and is often combined with Hyaluronic acid for a double hit of hydration. It has great skin tolerability (and also hair benefits - Pantene is even named after it, being the core ingredient in its formulations)

Other Vitamins in skincare

• Vitamin A aka retinoic acid. Retinoids, such as retinol and tretinoin, are a type of vitamin A that can help to reduce the appearance of fine lines and wrinkles. They're particularly effective for those with signs of ageing but can be irritating for those with sensitive skin.
• Vitamin C aka ascorbic acid. Ascorbic acid is the pure form of Vitamin C used in skincare. It has significant research behind its skin benefits of brightening the skin and reducing visible hyperpigmentation. 
• Vitamin B3 (Niacinamide). Whilst Niacinamide is technically not a true acid (the other, acid form of Vitamin B3 acid is known as niacin / nicotinic acid), we have included it on the list. Niacinamide is a fantastic skincare multi-tasker; it regulates sebum, reduces redness, strengthens the skin barrier and even fades hyperpigmentation.  

Azelaic acid in skincare

• Azelaic acid: Azelaic acid is an anti-inflammatory, great at treating rosacea symptoms (swelling & redness). Azelaic also has an anti-blemish activity - firstly, it is an antibacterial that works to kill acne-causing bacteria. Secondly, it prevents pores from becoming blocked by the skin’s natural shedding process.

How often to use acids in skincare

The frequency with which you use acids will depend on your skin type and the type of acid you're using. Certain acids, such as exfoliating acids or retinoic acid will generally need introducing slowly using once or twice a week and gradually increasing the frequency as your skin adjusts. Other acids such as hyaluronic acid or azelaic acid can generally be used daily from the get-go. It's important to follow the guidance of your aesthetician or skin professional and pay attention to your skin to see how it responds, in case you need to adjust your routine. 

Which skincare acids work better when paired?

Whilst acids are typically powerful and therefore make it important to practise patience, there are always ways to enhance their benefits, such as pairing them with other ingredients as part of a routine. Here are some examples of acid pairings that complement each other to target certain skin goals.

1. Azelaic acid and Niacinamide: When used together Azelaic acid helps to reduce inflammation and bacterial growth in acne, while Niacinamide helps to regulate sebum production and reduce the appearance of pores.
2. Vitamin A (retinoic acid)  and Vitamin C (ascorbic acid): When used in the same routine, this powerhouse duo helps to promote healthy ageing. Vitamin C in the morning offers antioxidant protection and promotes collagen production. Vitamin A in the evening helps promote skin regeneration and smooth texture. 
3. Salicylic acid and Niacinamide: When used together, Salicylic acid can exfoliate the skin, removing dead skin cells and unclogging pores, while Niacinamide can help to reduce inflammation, regulate sebum and even out skin tone. This can help to reduce the appearance of blemishes and blackheads.
4. Azelaic acid and Hyaluronic acid: When used together, Azelaic acid can help to reduce the appearance of blemishes and hyperpigmentation, while Hyaluronic acid can help to hydrate the skin and improve its moisture barrier. This can help to improve the texture and radiance of the skin, as well as soothe redness and inflammation.

Which skincare acids should not be used at the same time?

While some acids can work well together, others should not be used at the same time to avoid irritation or damage to the skin. Here are some examples of acids that should not be used together:

1. Retinoids and Alpha hydroxy acids (AHAs): Both of these acids can cause irritation and sensitivity, so it's best to use them at different times. Retinoids are best used at night, while AHAs can be used in the morning.
2. Benzoyl peroxide and Alpha hydroxy acids (AHAs): Benzoyl peroxide can make the skin more sensitive to AHAs, so it's best to use them at different times. Benzoyl peroxide is best used as a spot treatment, while AHAs can be used all over the face.
3. Vitamin C and niacinamide: While these two acids are beneficial on their own, they can cancel each other out when used together. It's best to use them at different times or choose a product that contains both.

By being aware of which acids pair well together and which should not be used at the same time, you can create a safe and effective skincare routine that will help you achieve your skin goals.

How long do skincare acids take to work on the skin?

The amount of time it takes for acids to work on the skin will vary depending on the type of acid you're using and your skin type. You might notice an almost instant hydrating and plumping effect from using a hydrating acid such as Hyaluronic acid, but it will take much longer to see results for acids that work their magic deeper within the skin, such as retinoic acid. It's important to be patient and consistent with your use of acids in order to see the best results.

If you’re thinking about adding acids into your routine and would like ongoing guidance and support or just some qualified advice from a real professional, take our skin quiz and book a free consultation with one of our Renude aestheticians. It’s quick, easy and they’re lovely to talk to!