How to build a PM skincare routine.

A morning skincare routine and an evening skincare routine are not the same routine applied twice. They have different objectives, use different categories of ingredients, and support different phases of the skin's own daily cycle. Understanding the distinction makes each routine more effective.

Why the PM routine is different

During daylight hours, the skin is in a defensive posture. Its priority is managing oxidative stress, UV exposure, and environmental insult. Many actives that work through cell turnover or barrier disruption are counterproductive in the morning — they sensitise the skin to UV, degrade in sunlight, or interfere with the defensive mechanisms the skin needs active.

At night, the dynamic reverses. Cortisol — the stress hormone that suppresses inflammatory response during the day — falls. Growth hormone secretion increases. Cell mitosis (the rate at which the skin produces new cells) peaks in the early hours of the morning. The skin shifts into active repair and regeneration. This is when cell-turnover actives, barrier-rebuilding ingredients, and hydration support are most effective.

Step one: cleanse properly

The evening cleanse is more demanding than the morning one. By end of day, the skin has accumulated sunscreen, makeup, oxidised sebum, and environmental particulate. A brief morning rinse is adequate on waking — at night, thorough removal is the prerequisite for everything that follows.

Double cleansing — an oil-based cleanser first, then a gentle water-based cleanser — is the most reliable method for complete removal when sunscreen or makeup has been worn. The oil phase dissolves lipid-based products; the second cleanser removes any remaining residue without disrupting the barrier. Double cleansing is not necessary on evenings when no sunscreen or makeup was applied — the single cleanser is sufficient.

The second cleanser used at night should not be more aggressive than the morning equivalent. Using a stripping foaming cleanser after an oil cleanser eliminates the benefit of the gentle first phase.

Step two: actives (if used)

The PM window is where most prescription and evidence-based over-the-counter actives belong.

Retinoids (retinol, adapalene, tretinoin) are the most important PM-only ingredients. They are degraded by UV light and increase UV sensitivity after application. They belong at night, and daily broad-spectrum SPF is non-negotiable when using them consistently.

AHAs (glycolic acid, lactic acid, mandelic acid) are photosensitising — they increase UV sensitivity in the days after use. PM application is the standard protocol.

BHAs (salicylic acid) are less photosensitising than AHAs and are used by some in morning routines, but PM is the conventional placement when also using a retinoid.

A note on combining: retinoids and AHAs used in the same application step create compounded irritation rather than compounded efficacy. Alternating evenings — retinoid one night, exfoliating acid the next — is the standard protocol for routines that include both.

Peptides, niacinamide, ceramide-based serums, and barrier ingredients can be used morning or evening and are often placed in the PM routine to complement the barrier-rebuilding phase.

Step three: moisturise — with more occlusion than morning

The PM moisturiser can be richer than the morning equivalent. At night, there is no sunscreen to apply over the top, no makeup, and no concern about how products wear through the day. The skin benefits from a heavier lipid component — squalane, shea butter, ceramides at higher concentration — than a lighter morning formula might include.

For very dry skin or during periods of barrier disruption (retinoid adjustment, cold weather, post-procedure), a small amount of occlusive — petrolatum, lanolin, or squalane alone — applied over the driest areas significantly reduces transepidermal water loss overnight. The mechanism is real; the full-face occlusion popular in some online communities is optional.

What does not belong in a PM routine

Vitamin C (L-ascorbic acid) is a morning antioxidant. Its function is intercepting UV-generated free radicals before they damage. Applied at night, it serves no meaningful antioxidant function in the absence of UV — and many L-ascorbic formulations are not stable enough to survive overnight on the skin. PM vitamin C is not harmful, but it is a misplaced effort.

SPF. There is no UV at night.

The minimal effective PM routine

Three steps:

1. Double cleanse (oil phase, then gentle water-based cleanser) if sunscreen or makeup was worn; single cleanse if not
2. Active of choice — retinoid or exfoliating acid on alternating evenings; skip if the barrier needs rest
3. PM moisturiser, richer than the morning equivalent; occlusive on very dry areas if needed

The Lux & Glo three-step works in the PM routine as it does in the morning. The cleansing oil serves as the first phase of a double cleanse. The niacinamide serum supports ceramide synthesis and sebum regulation during the repair window. The moisturiser provides the lipid reinforcement the barrier rebuilds overnight.

At night, the aim is to get out of the way of what the skin is already doing — and give it the materials it needs to do it.