Does the alpha-hydroxy in Ceramide AP mean it exfoliates?

No. The hydroxyl group sits on the ceramide's fatty acid chain and is a structural detail of the lipid; it is unrelated to AHA exfoliants such as glycolic or lactic acid.

What is Ceramide 6-II?

It is the older numeric name for Ceramide AP, and still appears on some ingredient lists alongside the letter-code form.

Is one ceramide enough in a moisturiser?

Reproducing the skin's native lipid organisation is generally thought to need several ceramide species together, which is why AP is usually formulated alongside other ceramides.

What percentage of ceramides is typical?

Barrier-repair formulations commonly use a blend at around 0.5%–2% total lipid content, generally with cholesterol and free fatty acids.

Is Ceramide AP restricted by regulators?

No. Ceramides are unrestricted cosmetic ingredients under EU CosIng and FDA cosmetic guidelines.

Ceramide AP — Ingredient Guide

How it works

Ceramide AP belongs to the family of sphingolipids that make up a major structural part of the stratum corneum. Its industry shorthand decodes as an alpha-hydroxy fatty acid (A) attached to a phytosphingosine base (P) — that hydroxyl group on the fatty acid chain is a structural feature of the lipid, and has nothing to do with the alpha-hydroxy acids used as exfoliants. Together with cholesterol and free fatty acids, in a ratio commonly cited as roughly 3:1:1, ceramides assemble into the lamellar bilayers that fill the gaps between corneocytes and act as the skin's main barrier to transepidermal water loss and to irritants moving inward. Applied topically, ceramides are believed to integrate into that lipid matrix and replenish what ageing, harsh cleansing, UV exposure or atopic dermatitis have depleted.

The evidence

Clinical work on ceramide-containing moisturisers — including barrier-repair trials in atopic dermatitis and photoaged skin — supports reduced transepidermal water loss and improved measures of barrier function. That evidence attaches to formulated ceramide blends rather than to Ceramide AP alone: replicating the skin's native lipid organisation is generally thought to require several ceramide species together, which is why AP normally appears next to NP and EOP-type ceramides rather than by itself. Its older numeric name, Ceramide 6-II, is still used on some ingredient lists.

Suitability

Suitable for every skin type and most valuable for dry, sensitive, eczema-prone, ageing or otherwise barrier-compromised skin, including skin being treated with retinoids or acids.

Concentration

Ceramide blends are typically used at roughly 0.5%–2% total lipid content in barrier-repair products. Individual species are rarely disclosed as separate percentages, so the presence of a plausible full blend tells you more than any single figure.

Conflicts & combinations

There is no meaningful conflict to manage — ceramides sit in the supportive category and combine with essentially all actives. Formulators pair them with cholesterol and free fatty acids to approximate the skin's own ratio, and with humectants such as glycerin.