Why skin starts to look dull

The outer layer of your skin, the stratum corneum, is made of flattened cells held together by protein links. Every day, a fine layer of these cells is meant to detach and shed, unseen, while fresh cells move up from below.

That shedding is not random. It relies on enzymes within the skin that gradually break the links between cells, a process known as desquamation. Rawlings and Voegeli (2013) describe how these protease enzymes control shedding, and how the process works less efficiently in dry skin conditions.

Age plays a part too. Grove and Kligman (1983) measured epidermal cell renewal in younger and older adults and found it was slower in the older group.

When shedding slows, more cells linger at the surface. A rougher, more built-up surface can look flatter. Dryness can also dull skin, so look at the whole routine, not exfoliation alone.

Exfoliation is a release, not a rub

Acid and enzyme exfoliants work alongside that natural process. Tang and Yang (2018) explain that alpha hydroxy acids, such as lactic acid, weaken the bonds holding surface cells together, so those cells loosen and shed. The same review notes that the effect depends heavily on concentration, pH and contact time, and that higher strengths can cause redness, burning and peeling.

A scrub works differently. It relies on particles and pressure to lift cells mechanically. How much it removes depends on the grain, how firmly you press and how long you rub, which is hard to judge consistently.

We could not find strong head-to-head research comparing facial scrubs with acid or enzyme exfoliants, so we will not claim one is proven better. Medico Beauty's approach is practical. We prefer exfoliants whose action comes from the formula rather than from force, because the strength is set by the product, not by your hand on a tired evening.

Medico Beauty's view

Four masks, and what each one does

Not every skin wants the same exfoliant, and not every mask is an exfoliant. Here is what the product information says about each.

CosMedix

Enzyme and acid exfoliation

Pure Enzymes Exfoliating Mask

Contains cranberry fruit and L-lactic acid, with gluconolactone further down the ingredient list. It is described as a gentle exfoliating mask that helps clear impurities and decongest pores.

CranberryL-lactic acidLeave-on mask

CosMedix

Enzyme exfoliation and brightening

Glow Bamboo Brightening Mask

Contains ficin, a plant enzyme, alongside L-lactic acid, niacinamide and two forms of vitamin C. It is described as removing dead surface cells first so its brightening ingredients can absorb, for smoother, more luminous-looking skin.

Ficin enzymeVitamin CRinse-off mask

CosMedix

Clarifying, for oily and congested skin

Clear Clarifying Mask

Contains bentonite and kaolin clays, sulfur and salicylic acid. It is described as a deep cleansing mask that lifts excess oil and helps minimise the look of pores. Best suited to oilier, blemish-prone skin.

ClaysSalicylic acidSulfur

CosMedix

Hydration, not exfoliation

Bio Cellulose Mask

A set of four sheet masks: two with damask rose flower water and sodium hyaluronate, two with sodium ascorbate, a form of vitamin C. It is described as deeply hydrating and brightening. We suggest it as a comforting step on days you are not exfoliating.

Sheet maskHyaluronateVitamin C

How often? Three separate answers

Frequency is where advice tends to blur, so here are three separate answers. They are not one combined schedule, and no single starting frequency suits everyone.

Exfoliation and the sun

This is the step that is easiest to forget. Kaidbey and colleagues (2003) found that four weeks of a 10% glycolic acid preparation made skin burn more readily under UV light than a placebo did. The effect had faded within a week of stopping. Kornhauser and colleagues (2009) reported a similar increase in UV sensitivity with 10% glycolic acid, but not with 2% salicylic acid.

These studies tested glycolic acid, not the masks above, so they do not tell us how any specific product behaves. They are still a good reason to pair acid exfoliation with daily sunscreen. Our guidance: if you are exfoliating, sunscreen is the final step every morning.