Know What's Inside: Sulfur, Zinc PCA, Salicylic Acid and AHA + PHA

The patch is a cosmetic, and the ingredient list is public, so here is what's on the film and what each part is there for, in plain language. No miracle claims, just what the ingredients are known for on skin.

Sulfur

One of the oldest ingredients in skincare for oily, blemish-prone skin. It helps manage the excess oil that collects in and around a spot, and it has a mildly drying, mattifying effect on the surface, which is part of why the patch takes makeup so well. The amount on a 12mm patch is small, and it's sitting on the spot rather than your whole face.

Zinc PCA

Zinc bound to pyrrolidone carboxylic acid, a molecule that occurs naturally in skin. It's used in oil-control products because it helps keep sebum in balance without stripping. On a patch it's the partner to sulfur: sulfur addresses the oil that's there, zinc PCA helps keep the surface calmer-looking while the patch is on.

Salicylic acid (BHA)

The exfoliant for pores. Salicylic acid is oil-soluble, so unlike water-soluble acids it can move into the oily environment of a blemish rather than sitting on top of it. It loosens the dead skin and debris that make a spot feel rough. A patch is a natural home for it, because the film keeps it in contact with the spot for hours instead of minutes.

AHA + PHA

Two gentler acids for the surface: citric acid, an alpha hydroxy acid, and lactobionic acid, a polyhydroxy acid with a larger molecule that works more slowly and is generally well tolerated by sensitive skin. Together they give the top of the spot a soft polish so it looks smoother and takes makeup more evenly.

The supporting cast

Niacinamide and panthenol for general skin support. Centella asiatica, tea tree, houttuynia, witch hazel and propolis extracts, all long-standing choices for skin that's prone to spots. Willow bark extract, which is a natural source of salicylates. Backhousia citriodora, better known as lemon myrtle. None of these are the headline act, but they're why the patch is formulated as a skincare product rather than just a sticker.

The film itself

The base is an acrylates copolymer, the same family of flexible, skin-safe polymers used in medical dressings and long-wear cosmetics. At 0.013mm it does two jobs: it holds the actives against the spot, and it gives a matte surface that foundation, concealer and powder can sit on. It doesn't absorb fluid and it doesn't turn white, because there's nothing in it to swell.

What it isn't

The patch is for external use on early-stage, emerging spots. It isn't a medicine, it isn't designed for open or cystic acne, and it won't do what a hydrocolloid dot does for a fully formed whitehead. If a spot is painful, persistent or spreading, that's a dermatologist question. Patch test before first use if your skin is reactive, don't apply it to broken skin, and stop if you notice irritation. The full ingredient list is on the product page.