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Is Lactic Acid Good for Acne Scars? (How to Use & Clinical Studies)

Is lactic acid good for acne scars? Whether you should choose this acid over other skincare ingredients will depend on your skin type, and the type of acne scars you want to treat.

This post explores the clinical evidence of using lactic acid for acne scars, as well as how to use it, and the possible side effects. It also helps you to decide which lactic acid product is right for you.

Is Lactic Acid Good for Acne Scars?

What Is Lactic Acid?

Lactic acid is an alpha-hydroxy acid (AHA) which is derived from milk.  Alpha-hydroxy acids are often found in skincare products since they help to exfoliate the skin and improve skin texture.

Other alpha-hydroxy acids include glycolic acid (from sugar), citric acid (from citrus fruit), malic acid (from apples) or tartaric acid (from grape).

Lactic acid and glycolic acid are the two most commonly used AHAs in skincare products. This is because they are the most well researched, and the ones least likely to cause skin irritation.

Benefits of Lactic Acid in Skincare

Lactic acid increases skin cell turnover. This means it helps to exfoliate dead skin cells, and make the skin appear brighter and smoother. Since it also attracts water molecules, it has the added benefit of keeping the skin hydrated.

Lactic acid is commonly found in skincare as a treatment for acne, scarring or hyperpigmentation. It is also believed to have anti-inflammatory and antimicrobial properties, and can be effective at reducing redness and irritation.

In general lactic acid is found in skincare products to:

  • Reduce fine lines and wrinkles
  • Help fade hyperpigmentation
  • Minimise age spots
  • Exfoliate the skin and unblock pores
  • Reduce Acne and blemishes
  • Help the skin to retain moisture
  • Smooth the complexion and improve skin tone
  • Promote collagen production
  • Increase blood flow in the skin
  • Brighten the complexion
  • Increase product absorption
  • Improve skin texture and tone
  • Treat keratosis pilaris or “chicken skin”

Lactic acid also has anti ageing benefits since it increases collagen production in the skin, although at a lesser rate than glycolic acid. It therefore not only reduces the appearance of acne scars, but also helps to minimise the appearance of fine lines. It’s a popular treatment to smooth scar tissue and lighten dark marks.

Since lactic acid is an effective treatment for clearing out the skin pores, it can be used on keratosis pilaris with good results. It is also an acne treatment, and will help to improve the appearance of your skin.

Benefits of Lactic Acid for Acne Scars

Clinical studies have shown that lactic acid reduces scarring by increasing the amount of collagen and hyaluronic acid in the skin. This makes the skin appear firmer and plumper. It also increases the skin’s elasticity and reduces scarring, fine lines and wrinkles.

Lactic acid is also able to reduce active acne and help to prevent future breakouts. This is because it helps to control oil production in the skin, and reduce the appearance of pores. It also removes dead skin cells and unblocks the pores, reducing the likelihood of future blemishes.

Reducing active acne is as important as minimising old scars, since the longer you leave acne untreated, the higher the chance of developing more scarring. Lactic acid is able to reduce both current pimples, and old scars.

Lactic acid can be effective on different types of acne scars including post-inflammatory hyperpigmentation, hypertrophic scars and keloid scars. Long term use helps to improve the skin’s texture and smooth out acne marks.

Clinical Studies into Lactic Acid for Acne Scars

There have been numerous studies into the effectiveness of using lactic acid peels to treat acne scarring. These studies showed that lactic acid not only reduced scars on the face, but was also effective at improving skin texture and minimising wrinkles.

Lactic Acid Improves Skin Texture

In a 2015 study, 52 volunteers used AHAs on their skin for three weeks. At the end of the three weeks nine out of ten participants saw an improvement in their skin texture. Wrinkles, fine lines and scarring on their skin were all reduced.

Lactic Acid Reduces Hyperpigmentation

A study from 2010, looked at the efficacy of using lactic acid to treat acne scarring in Indian skin. Patients with scars used lactic acid on their skin every two weeks for a three month period. After this time all the participants in the study saw a reduction in both hyperpigmentation and scarring on their skin.

Lactic Acid Combined with other Acids & Treatments

Other studies have shown that while lactic acid is effective at reducing acne scars, it’s often more effective when combined with other peeling agents. These include: salicylic acid, pyruvic acid, lactic acid, Jessner solution, trichloroacetic acid, mandelic acid, glycolic acid, and phenol.

Jessner solution is a mixture of lactic acid along with salicylic acid, and resorcinol, in 95% ethanol. Studies have shown that this combination can be effective at treating acne scars. Combination peels such as this are often used alongside other procedures such as microneedling in order to achieve the best results.

Possible Side Effects

Before using lactic acid on your skin, you should be aware that can can cause possible side effects including skin irritation or sun sensitivity. If you are using lactic acid in the form of a chemical peel it could also cause dryness, redness, burning, or itching.

The most important consideration when you first start using lactic acid, is to ensure you are wearing sunscreen every day. Since lactic acid exfoliates the top layer of skin, it can make the skin more sensitive to sunlight and more likely to be damaged by UV rays.

You should ensure you are using a SPF of at least 30 every day, and avoid being in direct sunlight for long periods of time. It’s important to continue using sun protection even after you stop using lactic acid on your skin, since the sun sensitivity can last for weeks after you stop using it.

Lactic Acid vs Glycolic Acid for Acne Scars

Lactic acid and glycolic acid are both commonly used acids to treat acne scars. Lactic acid has larger molecules compared with glycolic acid, and therefore doesn’t penetrate as deeply into the skin.

This means that lactic acid is more gentle that glycolic and may be better for people with sensitive skin. It’s also better at keeping the skin hydrated and treating sun damage.

Glycolic acid on the other hand is better at clearing out the skin pores and removing dead skin cells and dirt. This is because the molecules are much smaller, and it is able to work at a much deeper level in the skin. It is very effective at smoothing out uneven skin texture, and reducing wrinkles and acne scars.

In general, you should choose lactic acid if you have dry or sensitive skin, or you want to treat sun damage. Glycolic acid is for skin that’s not as sensitive, and can help to smooth deeper acne scars. It’s also possible to use both glycolic and lactic acid together in the same skincare routine.

Lactic Acid vs Salicylic Acid for Acne Scars

Whereas lactic and glycolic acid are both alpha hydroxy acids (AHA), salicylic acid is a beta hydroxy acid (BHA).

BHAs are different from AHAs in that they are oil soluble instead of water soluble. AHAs are also made from food products like fruits, sugar or milk, whereas BHAs are made from trees like willow bark or sweet birch.

Since BHAs are oil soluble, they are able to penetrate deeper into the pores, and are more effective at clearing out excess oil or dead skin cells.

A clinical study from 2012 showed that although both lactic and glycolic acid were effective at treating acne and scarring, salicylic acid actually produced better results. This may be because salicylic acid is oil soluble and better able to remove excess sebum from the skin.

In general salicylic acid is a better choice to treat acne scars in oily skin that’s prone to breakouts. Lactic acid is better for treating acne scars in dry or dehydrated skin, or skin that is sun damaged. You can also alternate between salicylic and lactic acid to get the benefits of both.

Salicylic acid is also a more gentler option that glycolic to combine with lactic acid.

How to Use Lactic Acid for Acne Scars

Lactic acid can be found in different skincare products including cleansers, creams, serums or at-home masks and peels. It also comes in different concentrations:

  • Lighter strength: 5-10% lactic acid content
  • Medium strength: 10-15% lactic acid content
  • High strength: Over 15% lactic acid content

When you first start using lactic acid you should use a product a maximum concentration of 10% to allow your skin to get used to the ingredient. The stronger the concentration, the faster the results, but stronger concentrations also lead to greater chance of skin irritation.

Using Lactic Acid Products at Home

Lactic acid products that remove acne scars

There are many over the counter lotions, face washes and masks that contain lactic acid. If you have especially sensitive skin, you may wish to choose a lactic acid cleanser since it’s only on the skin for a short period of time before being washed off.

If you use a cream or serum, these are best used only at night since lactic acid makes the skin more sensitive to the sun. When you first start using the products you may also want to introduce them gradually to give your skin a chance to get used to the product.

If you are looking for a good lactic acid product to get started, The Ordinary products are a good place to start. The Ordinary make a lactic acid solution that contains 10% lactic acid and 2% hyaluronic acid. It’s a great option if you want to treat acne scars on dry skin. It also works well on sensitive skin types since The Ordinary Lactic Acid contains Tasmanian Pepperberry extract which helps to reduce redness and inflammation.

Professional Lactic Acid Peels

According to the Mayo Clinic professional peels for acne scars produce longer-lasting benefits, but also have a greater risk of discomfort, and longer recovery time.

If you have superficial acne scars, dark spots, age spots or uneven skin tone, over the counter products may be sufficient to achieve smooth skin. If you have much deeper scars however, professional chemical peels or laser treatments might be required to see the same results.

A professional strength chemical exfoliant should only be used as a last resort however. Professional treatments have a long recovery time, so it is advisable to first try an at-home treatment. Using a mixture of over-the-counter alpha and beta hydroxy acids at home may be the best way to treat acne scarring without the harsh side effects.

Contraindications to Lactic Acid

Although lactic acid is the most gentle of all the alpha hydroxy acids, it is recommended you don’t use it if you have eczema, psoriasis or rosacea. If you have darker skin tones you should also check with a dermatologist before using lactic acid since it has been found to increase the risk of hyperpigmentation in darker skin types.

If you are already using retinol you also may want to avoid lactic acid as it could make your skin too sensitive or cause redness, irritation or peeling.

FAQs on Using Lactic Acid for Acne Scars

What does a yogurt face mask do?

Yoghurt contains lactic acid, so can be used as a natural remedy to treat acne scars and reduce skin discolouration. It also helps to moisturise and tone the skin, and reduce acne. You can easily make a yoghurt face mask at home by mixing in ingredients such as aloe vera, honey or turmeric.

How long does it take lactic acid to fade acne scars?

This will depend on the strength of lactic acid you are using, and how often you are applying it to the skin. One study showed that applying lactic acid once every two weeks helped to lighten acne scars and improve skin texture after three months.

When should you use lactic acid in your skincare routine?

Since lactic acid makes the skin more sensitive to the sun, it’s best to use it at night time. If you are using a lactic acid serum, apply it after your toner and before your moisturiser in the evening. When you first start using lactic acid start by using it 2-3 times a week and gradually build up to using it daily.

Sources Used in this Post

  1. Healthline – Everything You Need to Know About Using Alpha Hydroxy Acids (AHAs)
  2. WebMD – An Overview of Alpha Hydroxy Acids (AHAs)
  3. PubMed – Comparative effectiveness of alpha-hydroxy acids on skin properties
  4. WebMD – What to Know About Lactic Acid for Skin Care
  5. American Academy of Dermatology Association – Acne Scars: Who gets and causes
  6. NCBI – An antiaging skin care system containing alpha hydroxy acids and vitamins improves the biomechanical parameters of facial skin
  7. PubMed – Lactic acid peeling in superficial acne scarring in Indian skin
  8. WebMD – Hyperpigmentation, Hypopigmentation, and Your Skin
  9. PubMed – Chemical peels in active acne and acne scars
  10. NCBI – Efficacy of Modified Jessner’s Peel and 20% TCA Versus 20% TCA Peel Alone for the Treatment of Acne Scars
  11. PubMed – Microneedling (Dermapen) and Jessner’s solution peeling in treatment of atrophic acne scars: a comparative randomized clinical study
  12. Very Well Health – An Overview of Lactic Acid Skin Care
  13. Healthline – A Guide to the Confusing World of Face Acids and Which Ones to Use
  14. AAMJ – Salicylic acid versus Lactic acid peeling in mild and moderate acne vulgaris
  15. Cleveland Clinic – Understanding the Ingredients in Skin Care Products
  16. Heathline – Everything You Need to Know About Lactic Acid Peels
  17. Mayo Clinic – Skin Resurfacing Options That Smooth Facial Wrinkles
  18. NCBI – Applications of hydroxy acids: classification, mechanisms, and photoactivity
  19. NCBI – Evidence and Considerations in the Application of Chemical Peels in Skin Disorders and Aesthetic Resurfacing
  20. PubMed – Increased in vivo collagen synthesis and in vitro cell proliferative effect of glycolic acid
  21. NHS – Information on Keratosis pilaris
  22. Cleveland Clinic – What are Hypertrophic Acne Scars?
  23. NHS – What are Keloid Scars?

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Is Lactic Acid Good for Acne Scars?

Thank you for reading my post about using lactic acid for acne scars. If you have had any experience using lactic acid, please leave me a comment below and let me know how you got on.