Capryloyl Salicylic Acid

Capryloyl salicylic acid is a derivative (ester) of salicylic acid developed by L’Oreal. In chemistry circles, it’s known as 2-hydroxyl-5-octanoyl benzoic acid, but skin care consumers most likely know it has lipohydroxy acid (LHA). The “lipo” portion is oil-soluble, although so is regular salicylic acid.

To date, studies haven’t shown capryloyl salicylic acid is superior to salicylic acid; however, we know that LHA has a larger molecular size and along with its fatty acid structure has been shown to penetrate the skin slower than salicylic acid. In vitro studies have shown LHA tends to stay within the stratum corneum (the outermost layers of skin), while salicylic acid penetrates up to 58% further. This limitation may explain why capryloyl salicylic acid is not considered as effective for acne as salicylic acid. Speaking of acne, there is comparative research showing capryloyl salicylic acid used with benzoyl peroxide and/or a topical antibiotic produced slightly better results than using benzoyl peroxide and the topical antibiotic alone. While that’s encouraging, if you’re struggling with acne, regular salicylic acid should remain your go-to exfoliant.

Just like salicylic acid, the capryloyl derivative has exfoliating and soothing properties as well as documented improvement in skin tone, wrinkles, and clogged pores. It also has the same formulary requirements around the pH range it works best, although unlike salicylic acid, in skin care LHA’s concentration is typically no greater than 1%.

Interestingly, comparative research hasn’t focused on salicylic acid; instead, the single study that exists compared capryloyl salicylic acid to the alpha hydroxy acid (AHA) glycolic acid. In such instances, lower amounts (5-10%) of capryloyl salicylic acid were shown to produce an equivalent to superior level of visible improvement compared with much greater (20-50%) concentrations of glycolic acid. Due to the natural calming properties salicylic acid has, it wasn’t surprising that the LHA peels were perceived as less irritating than the AHA peel.

Capryloyl salicylic acid is generally considered safe when used as directed. Note: Although studies on this ingredient were generally well done and followed scientific principles, it’s worth noting that all of them were either done by, funded by, or otherwise supported by L’Oreal. This does not mean the results cannot be counted on, only that there was incentive to cast this ingredient in its best light.