Thymol is a natural monoterpene phenol derived from thyme oil (Thymus vulgaris) and is well-known for its antimicrobial properties. Its use in supporting or treating acne has some scientific basis, primarily due to its antibacterial activity against Propionibacterium acnes (now known as Cutibacterium acnes), a key bacterium involved in acne pathogenesis. Several in vitro studies have demonstrated thymol’s effectiveness in inhibiting the growth of acne-causing bacteria and reducing inflammation, both of which are central to acne development.

However, most of the evidence comes from laboratory studies rather than large, well-controlled clinical trials in humans. Some topical formulations containing thymol or thyme extract have been tested in small-scale studies and have shown promise in reducing acne lesion counts, but these studies are limited in size and quality. There is also evidence that thymol's anti-inflammatory properties may help calm irritated skin, a benefit relevant to acne treatment.

In summary, thymol’s use for acne has some scientific validation, mainly due to its demonstrated antibacterial and anti-inflammatory effects in preclinical studies. However, the overall evidence is still preliminary, and more robust clinical trials are needed before thymol can be considered a fully established or frontline acne treatment.