Oil Control Pads

Three acids, chosen because they behave differently from one another.

Salicylic acid is a beta hydroxy acid and oil-soluble, so it moves into the sebum within a pore rather than working only on the surface. That is why it appears in formulations aimed at congestion. It sits fourth in the ingredient list here.

Mandelic acid is an alpha hydroxy acid derived from bitter almonds, and the largest of the commonly used AHAs. Being larger, it penetrates more slowly than glycolic acid, which makes it noticeably better tolerated. It is also more lipophilic than other AHAs, so it has some affinity for oily skin.

Glycolic acid is the smallest AHA and works fastest on the surface, loosening the bonds between corneocytes.

Combining a fast, small acid with a slow, large one is a way of getting surface exfoliation without relying on a single aggressive ingredient.

Urea acts as both humectant and keratolytic depending on concentration, supporting the acids in loosening the outer layer.

The astringent and cooling layer

Witch hazel is a traditional astringent, containing tannins that temporarily tighten the appearance of skin. Rosa canina, rosehip, is included in oil-control formulations for its effect on the appearance of pores.

Menthyl lactate is a menthol derivative that produces a cooling sensation. It is milder and longer-lasting than menthol itself, and it accounts for the immediate freshness these pads are known for.

The alcohol base

Alcohol is the second ingredient. It acts as a solvent, dries quickly, and produces the matte finish. That also means the formula is drying, which is deliberate for oily skin and unsuitable for skin that is not. The pack carries a flammability warning for the same reason.

The t-butyl alcohol and denatonium benzoate are denaturants. Denatonium benzoate is among the most bitter compounds known and is present purely to make the alcohol undrinkable.

Fragrance

Fragranced, with four recognised contact allergens declared on the pack: citronellol, hexyl cinnamal, limonene and linalool.

Oily and congestion-prone skin, particularly where shine through the day is a concern. Suits skin that already tolerates acids.

Not the right product if your skin is dry, sensitive or reactive, if you have rosacea, or if you have reacted to fragrance. Three acids in a high-alcohol base is demanding, and there are gentler options.

Wipe one pad over cleansed skin, avoiding the eye area. Do not rinse.

Build up gradually. ZO's own directions advise starting with one application daily and increasing to two or three only if needed, reducing frequency if dryness or peeling develops. Given three acids and an alcohol base, starting lower than that is reasonable, and your doctor can advise on the right frequency for your skin.

Sun protection is mandatory. The pack requires sunscreen, protective clothing and limited sun exposure while using this product and for a week after stopping. Broad-spectrum SPF 30 or higher, daily, without exception.

Keep apart

Any other exfoliant on the same day. Three acids is already a lot.

Retinoids in the same session. Alternate evenings.

Vitamin C serums immediately afterwards, where the low pH may cause stinging.

Use alongside

A moisturiser afterwards. This formula is drying by design.

Daily broad-spectrum SPF, continuing for a week after you stop.