BHA: Salicylic acid

BHA The ingredient you need! Pimples, acne, complexion

BHA offers numerous benefits for getting rid of blemishes that just won't go away, unclogging pores and fighting pimples, but you still need to know how to use it properly, incorporate it correctly into your skincare routine and, above all, choose the right products.

Properties of salicylic acid for the skin

To fight blemishes, salicylic acid has a special feature that other exfoliating acids don't have. It is fat-soluble.

AHAs like glycolic acid or lactic acid are water-soluble and act on the skin's surface, but only slightly inside the pores. They are ideal for anti-aging or for improving skin texture, but for problems of dilated pores or skin imperfections, salicylic acid is the ideal candidate. Generally speaking, pores can become clogged due to an excess of dead cells, often caused by hyperkeratinization, excessive sebum production or simply make-up residue, and a fat-soluble ingredient like BHA is better at unclogging pores than any other exfoliant.

But salicylic acid isn't just an exfoliating acid: it has been found to inhibit the growth and proliferation of fungi, viruses and bacteria, including Cutibacterium acnes, certain strains of which are responsible for acne.

It's also an anti-inflammatory active ingredient, which is particularly interesting because inflammation is the main cause of redness, raised skin and increased pimple size. And the advantage of acting on inflammation when you have a blemish is that the result is relatively rapid.

The last notable action is that salicylic acid regulates sebum production, as shown in the study below.

Regulations governing BHA in facial care products

European regulations stipulate that the maximum concentration of BHA in cosmetic products must be 2%, but the PH and galenic properties of the product can be adjusted to increase its efficacy and tolerance. Ideally, a PH between 3 and 4 is desirable to ensure that the product is effective without irritating your skin. For example, a lotion will be more effective than a product in gel form, but the gel form will increase the product's tolerance.

Just a reminder: like other exfoliating acids, BHA is photosensitizing, so don't hesitate to protect your skin from the sun with SPF 50.

How often should I exfoliate her skin?

Now for an important question: How often should I exfoliate my skin with a BHA? It depends on many factors: if you have a healthy skin barrier, if you don't already exfoliate your skin with other products, and if your skin type is normal, combination or oily, you can use a BHA exfoliant every day, but as a precaution if you're not used to using this product, it's best to start every other day.

Other criteria I've forgotten include the type of cleanser you use: aggressive or gentle, do you moisturize your skin properly or do you use retinoids? In conclusion, always test and observe how your skin reacts, and adapt your skincare routine accordingly.

How to combine exfoliating acids?

Now let's see which active ingredients to combine BHA with. First of all, I don't think it's really useful to use a BHA and AHA product on the same day. But it may be useful to alternate between BHA and AHA, as AHAs are more effective at reducing the visible signs of sun damage such as spots and wrinkles. And if you want to alternate between the two types of exfoliants there are two possible options. 

If your main problem is blemishes, you can use a BHA during the week and an AHA exfoliant at the weekend. If, on the other hand, you have a dual problem of acne-prone skin and anti-aging, you can alternate a BHA and an AHA every other day or every 3rd day.

Now let's see what other active ingredients BHAs can be combined with.

A good combination as part of an anti-aging routine is to use a BHA and a vitamin C serum in the morning, the aim being to play on the acidity of the two cosmetic products to increase their potency. This combination is highly effective, as one of the most important criteria for improving the effectiveness of a vitamin C serum or an exfoliating acid is the PH: the lower the PH, the more effective the product. And by applying an exfoliating acid and a vitamin C serum, both products will benefit from each other's PH, maximizing their action. As for the order of application, if you're using a very fluid exfoliant like the lotion, I advise you to use it before your vitamin C serum, but if you're using Paula's choice BHA gel or AHA gel, I advise you to use them after your vitamin C serum.

Among the ingredients not to be used in conjunction with a BHA exfoliant are retinol and copper peptide, which do not stand up well to acidic PH and render them ineffective.

I hope you enjoyed this video and feel free to share your thoughts on salicylic acid and your best products in the comments.

Lu J, Cong T, Wen X, Li X, Du D, He G, Jiang X. Salicylic acid treats acne vulgaris by suppressing AMPK/SREBP1 pathway in sebocytes. Exp Dermatol. 2019 Jul;28(7):786-794. doi: 10.1111/exd.13934. Epub 2019 May 15. PMID: 30972839.