What Are Chemical Peels?
A chemical peel is a skin resurfacing treatment in which a carefully selected acid solution is applied to the skin to remove damaged outer layers, revealing fresher, smoother, more evenly toned skin beneath. By controlling the type of acid, its concentration, and the duration of application, practitioners can treat a remarkably broad range of skin concerns, from mild dullness and uneven texture to deep wrinkles, pigmentation, and acne scarring.
Chemical peels have been used in dermatology for over a century, with modern formulations developed through the 20th and 21st centuries. They remain one of the most well-established and thoroughly researched skin treatments available. In Ireland. They are one of the most popular and accessible aesthetic treatments, offered by dermatologists, doctors, and qualified nurses, and, within the scope of their practice, some dentists, across the country.
The treatment works on a simple but powerful principle: controlled removal of damaged layers to trigger renewal. The acid solution dissolves the bonds holding dead and damaged skin cells together, prompting the skin's natural healing response. As the treated layers shed (peel), new cells are generated from the deeper, undamaged layers of the skin. This new skin is typically smoother, more evenly pigmented, and firmer, with improved collagen content.
Chemical peels are classified into three categories based on the depth of penetration: superficial (affecting only the epidermis), medium-depth (reaching into the upper dermis), and deep (penetrating to the mid-dermis). The deeper the peel, the more dramatic the results, but also the longer the recovery and the higher the associated risks. Your practitioner will recommend the appropriate depth based on your skin type, concerns, and lifestyle.
Common acids used in chemical peels include glycolic acid, lactic acid, salicylic acid, mandelic acid, and trichloroacetic acid (TCA), each with different properties and suited to different skin types and concerns.
A note on phenol (deep) peels. True phenol peels are specialised, medically intensive procedures that carry systemic risks, phenol is cardiotoxic, and genuine phenol peels require cardiac monitoring, IV hydration, and medical supervision comparable to a minor surgical procedure. They are rarely offered outside specialist dermatology or plastic surgery settings in Ireland. Most treatments marketed as "deep peels" in Irish aesthetic clinics are in fact high-concentration TCA or deeper medium-depth peels, not true phenol peels. This guide focuses on the superficial and medium-depth peels that are routinely available in Ireland.
How Do Chemical Peels Work?
The chemical peel process varies depending on the depth and type of peel, but the general procedure follows these steps:
Pre-treatment consultation and preparation: Your practitioner will assess your skin, discuss your concerns, and determine the most appropriate type and depth of peel. They may recommend a preparatory skincare regime for 2 to 4 weeks before the peel, this may include a retinoid and, if needed for pigmentation concerns, a prescription-only pigment-regulating agent such as hydroquinone (available only on prescription in Ireland and the EU, and only prescribed by a doctor). Daily SPF is essential throughout preparation. Retinoids used to prime the skin in the weeks beforehand should typically be stopped 5 to 7 days before the procedure itself to reduce post-peel sensitivity. For medium and deep peels, prophylactic antiviral medication is typically prescribed for several days before and after treatment, even in patients without active cold sores, to prevent reactivation of herpes simplex virus.
Cleansing and degreasing: On the day of treatment, the skin is thoroughly cleansed and degreased to ensure even penetration of the acid solution. Any residual oils, makeup, or skincare products are removed.
Application of the acid solution: The peel solution is applied to the skin using a brush, gauze, or cotton applicator. Your practitioner will monitor your skin's reaction carefully throughout the application.
- Superficial peels are typically left on for 1 to 5 minutes. You may feel a mild tingling or warming sensation.
- Medium-depth peels may be applied in one or more layers, with the practitioner assessing the skin's response between layers. The skin may develop frosting, a whitening of the skin that occurs during medium-depth peels, indicating protein coagulation. Frosting is expected and indicates the peel has reached its intended depth. A stinging or burning sensation is normal and typically lasts a few minutes.
- Deeper peels are applied in a highly controlled manner, section by section, and may require topical anaesthesia due to the intensity of the procedure.
Neutralisation: Glycolic acid and some alpha-hydroxy acid peels require a neutralising solution to stop the acid's activity. TCA is self-limiting, the acid is consumed as it reacts with skin proteins, so active neutralisation is not required, though cool compresses may be used for comfort.
Post-treatment care: A soothing balm, serum, or cooling mask is typically applied. Your practitioner will provide detailed aftercare instructions tailored to the specific peel you received.
Over the following days and weeks, the treated skin undergoes a controlled exfoliation, and new, healthier skin emerges. The depth and duration of peeling depend on the type and strength of the peel used.
A note on visible peeling. Not all peels cause dramatic visible peeling. Many superficial peels produce real results without significant skin shedding, and the degree of peeling does not necessarily correlate with the effectiveness of the treatment. If you do not see dramatic flaking after a superficial peel, it does not mean the peel has not worked, the biological response can be occurring beneath the surface.