By: Cosmecell
This is a professional reference for licensed estheticians and skincare practitioners. It does not replace your state licensing board's scope-of-practice rules, your training, or a client-specific clinical assessment — always confirm what your license and jurisdiction permit before performing any peel.
Percentage Alone Doesn't Tell You the Depth
A common misconception, even among practitioners, is that percentage maps directly to depth. It doesn't. Depth depends on the acid type, the percentage, the pH, contact time, number of layers, and the skin it's being applied to. That said, percentage within a given acid type is still the most useful starting reference point, so here's how the field is generally classified.
The Three Depth Categories
Superficial Peels
Typically glycolic acid in the 20–30% range, salicylic acid 20–30%, or Jessner's solution. These affect the epidermis only, produce minimal to no visible peeling, and generally carry the lowest risk profile — which is why they're the most common starting point for estheticians and the least restricted by scope-of-practice rules in most jurisdictions.
Medium-Depth Peels
Typically TCA (trichloroacetic acid) in the 35–50% range, or higher-percentage multi-acid combination peels. These reach into the papillary dermis, produce visible frosting and several days of peeling, and are used for more significant concerns — post-inflammatory hyperpigmentation, melasma, moderate photodamage. This category requires more training, more precise technique, and in many jurisdictions, additional certification or physician oversight.
Deep Peels
Phenol-based or high-concentration TCA formulations that reach the reticular dermis. These are typically restricted to physicians and are outside the scope of standard esthetician licensure in nearly every jurisdiction.
Where a 43% Multi-Acid Peel Fits
Cosmecell's Skin Clarity Peel is a 43% multi-acid formulation — primarily glycolic acid, with citric and lactic acid — which places it in the medium-depth category. It's built for post-inflammatory hyperpigmentation, melasma-prone skin, and uneven tone: concerns that generally need more than a superficial peel can deliver, without stepping into deep-peel territory that requires physician-level oversight. That's a deliberate positioning — it's why the product is licensed-professional-only rather than sold for home use.
What Actually Determines Contact Time
Fixed timing charts are a starting reference, not a rule to follow blindly. Contact time should be set by what you observe on the client's skin — even erythema or light frosting as the visual endpoint — rather than a stopwatch alone. As a general range: thinner, more reactive skin (first-time clients, periorbital and neck areas, rosacea-prone) typically needs 1–3 minutes; normal, resilient skin often falls in the 4–8 minute range; thicker, peel-conditioned skin under direct monitoring may tolerate 9–15 minutes. Neutralize immediately at the visual endpoint, or sooner if the client reports excessive burning.
Non-Negotiables Before Increasing Strength
- Patch test 24–48 hours ahead of a client's first treatment at any new strength.
- Screen for active dermatitis, eczema, broken or sunburned skin, recent isotretinoin use, and pregnancy per your clinic's standing protocol.
- Confirm your state's scope-of-practice rules for the specific acid and percentage — this varies significantly by state and changes periodically.
- Never increase percentage or acid type based on a client's request alone; base it on skin assessment and documented tolerance.
The Takeaway
Percentage is a reference point, not a prescription — depth is determined by acid type, pH, layering, and contact time together, and contact time itself should be set by what you see on the skin, not a fixed clock. Know your jurisdiction's scope-of-practice rules before working above the superficial range. See the Skin Clarity Peel formulation.