How to Layer Facial Oils in a Skincare Routine: Where They Go and Which Skin Types Need Them
Facial oils generate more confusion about placement than almost any other product category. They go after moisturiser, not before — but walk into any beauty retailer and you will find them marketed interchangeably as serums, treatments, and finishing products, with instructions that contradict each other and each other's logic. The reason layering position matters for oils is specific and based on chemistry: oils are hydrophobic (water-repelling), which means applying an oil before a water-based serum or moisturiser creates a partial barrier that prevents the subsequent water-based product from penetrating. Getting the sequence wrong does not make the products dangerous — it makes them less effective.
Quick Answer
Facial oils go after moisturiser as the second-to-last PM step (before any occlusive like petrolatum, if using one — never before SPF in AM). They function as emollients and mild occlusives, filling the gaps in the stratum corneum's lipid matrix and slowing transepidermal water loss. They do not replace moisturiser — a moisturiser contains the humectants and barrier lipids that an oil alone does not. Not every skin type needs a facial oil; dry, normal, and mature skin types benefit most. Oily and acne-prone skin should choose carefully and favour non-comedogenic oils like squalane.
Why Oils Go After Moisturiser
The fundamental rule is that oil and water do not mix — and in skincare, water-based products cannot penetrate an oil layer effectively. If you apply a facial oil first, the water-based serum and moisturiser you apply over it will sit on top of the oil film rather than penetrating the skin. You will feel the moisturiser on the surface but its humectants and active ingredients will have limited contact with the stratum corneum.
The correct sequence respects the oil-water barrier: water-based products first (cleansed skin → serum → moisturiser) then the oil last as the final leave-on step before SPF (AM) or before sleep (PM). The oil sits on top of the moisturiser, slowing the evaporation of the moisture that has been delivered beneath it — acting as a light occlusive seal without the heaviness of petrolatum or silicone-based occlusives. This is also why oils are generally PM-only products: applying an oil before SPF in the morning dilutes the SPF film and reduces its coverage and adhesion to skin. The exception is products where an oil is already incorporated into the SPF formulation — those are fine.
What Facial Oils Actually Do
Oils function primarily as emollients — they fill the spaces between corneocytes (the flattened dead skin cells in the stratum corneum), smoothing the surface texture and improving the barrier's resistance to water loss. Some oils also deliver biologically active fatty acids — notably linoleic acid (omega-6), which is a component of the skin's own barrier lipids and is often deficient in acne-prone skin. Oils rich in linoleic acid (rosehip, evening primrose, hemp seed) have evidence for supporting barrier function and reducing acne-associated inflammation. Oils high in oleic acid (argan, marula, avocado) are richer and more occlusive — better for dry and mature skin, potentially problematic for acne-prone skin.
Squalane deserves special mention. Unlike most facial oils, it is not a triglyceride oil but a saturated hydrocarbon derived from olives (or sugarcane). It closely mimics the skin's own squalene (a component of sebum), is stable, non-comedogenic, and appropriate for essentially all skin types including oily and acne-prone. It is the most universally usable facial oil and the one to start with if you are unsure whether your skin tolerates oils well.
Comedogenicity: Which Oils Are Safe for Acne-Prone Skin
Comedogenicity ratings — the 0–5 scale that appears on oil ingredient databases — are frequently misunderstood. They are derived from laboratory tests on rabbit ear skin, which is far more reactive to comedogenic substances than human facial skin. The real-world comedogenicity of an oil on your face depends on the formulation, the concentration, your individual skin, and whether the product stays on the skin surface or penetrates. Some oils rated moderately comedogenic (coconut oil, for instance) are genuinely problematic for many acne-prone people; others rated similarly cause no issues. This is not a precise science.
As a practical guide: squalane (rated 0–1, very low) and rosehip oil (rated 1, low) are the safest choices for acne-prone skin. Jojoba oil (technically a wax ester, rated 2) is widely tolerated by oily skin. Avoid coconut oil on the face if you are acne-prone (rated 4, high comedogenicity, supported by real-world reports). For a full list of oils and their real-world acne compatibility evidence, check the Skin Stacker Ingredient Decoder.
Oils by Skin Type
| Skin Type | Best Oils | Why | Avoid |
|---|---|---|---|
| Dry / mature | Rosehip, marula, argan, avocado | Rich oleic acid content; deep emollience; anti-ageing fatty acids in rosehip | Nothing specific — rich oils work well |
| Normal / combination | Squalane, jojoba, rosehip | Lightweight, balancing; jojoba mimics sebum chemistry | Very heavy oils (avocado, castor) on T-zone |
| Oily / acne-prone | Squalane, rosehip (patch test first) | Non-comedogenic; squalane replaces sebum deficit without clogging; rosehip delivers linoleic acid | Coconut oil, cocoa butter, wheat germ oil |
| Sensitive / rosacea | Squalane, hemp seed oil | Anti-inflammatory fatty acids; minimal fragrance risk; gentle | Fragrant oils (rose, citrus-derived), essential oil blends |
The AM vs PM Question
Most facial oils are best reserved for PM use for two reasons. First, the occlusive nature of an oil layer applied before SPF interferes with SPF film uniformity. Second, oils can create a slight sheen that makes makeup application more difficult. The exception is a very small amount of a dry-finish oil like squalane mixed into a BB cream or moisturiser — this is a legitimate formulation approach used by many people, and at that volume does not meaningfully compromise SPF. For the full AM routine sequence, see our morning routine order guide and the science of layering order for the principles behind why oil goes last. Build your full routine in the Skin Stacker Routine Builder to confirm the correct position for your specific products.