Acne is an inflammatory skin condition that affects people of any age, even sometimes occurring for the first time well into adulthood. Many plants possess chemical compounds that lend them acne-fighting antibacterial and anti-inflammatory properties, which are harnessed in their essential oils. In clinical studies, certain essential oils really stand out in effectiveness.
Tea tree (Melaleuca alternifolia) is well known for its antifungal and antimicrobial properties and it is commonly found among the ingredients in many over-the-counter acne treatments. In one clinical study, 5% tea tree oil was found to be better tolerated than 5% benzoyl peroxide, although its visible effects took slightly longer to appear. In a randomized placebo-controlled trial, subjects with mild to moderate acne who used tea tree oil every day for 45 days reported less inflammation and redness than those who were treated with placebo.
Rosemary (Rosmarinus officinalis) contains a number of active constituents that offer antibacterial and antioxidant properties, including 1,8-cineole, acetic acid, camphor, carnosol, carvacrol, carvone, geraniol, hesperidin, limonene, luteolin, rosmarinic acid and salicylates. In addition to treating acne, rosemary essential oil is also helpful in reducing the symptoms of eczema.
Thyme has a long history of use as an antiseptic, from the plague that afflicted Medieval Europe to the battlefields of World War I. Its potent antiseptic action is primarily due to the presence of thymol.
Lavender (Lavandula angustifolia) is highly anti-inflammatory, antimicrobial and antiseptic due to a variety of aldehydes and ketones and specifically an alcohol called linalool that occurs in lavender essential oil in a concentration of up to 50%. Lavender is one of the few essential oils that can be applied to the skin "neat," meaning undiluted.
As noted, with the exception of lavender, most essential oils should be diluted in a carrier medium before applying to the skin. You can place a drop on a damp cotton ball for spot applications, or add a few drops to cooled chamomile or green tea to use as a facial splash. Essential oils may also be added to other skin care products, such as facial soaps (liquid or bar), lotions, and toners.