Skincare labels are a wall of jargon, and a lot of it is designed to sound more impressive than it is. Here's a straight definition of the ingredients and terms that come up most — what they actually do, where the evidence is solid, and where it's thinner. None of this is medical advice; it's a reference to help you read a label.
Actives & treatments
Retinoids (retinol, retinaldehyde, tretinoin)
Vitamin A derivatives that increase skin-cell turnover. Good evidence for improving fine lines, texture and acne over months of consistent use. Strength rises from retinol to retinaldehyde to prescription tretinoin. Can irritate at first; not recommended in pregnancy or breastfeeding. See our retinol guide.
Vitamin C (L-ascorbic acid & derivatives)
A daytime antioxidant that can help brighten tone and support collagen. L-ascorbic acid is the best-studied but oxidises easily; derivatives are more stable but often less potent. See our vitamin C guide.
Niacinamide (vitamin B3)
A well-tolerated multitasker. Reasonable evidence for supporting the skin barrier and helping with redness, oiliness and uneven tone. Plays nicely with most other ingredients, including vitamin C.
AHAs (glycolic, lactic, mandelic acid)
Water-soluble chemical exfoliants that loosen dead cells on the surface, helping with dullness and texture. Glycolic is the strongest/smallest; lactic and mandelic are gentler. They can increase sun sensitivity — wear SPF.
BHA (salicylic acid)
An oil-soluble exfoliant that gets into pores, which makes it useful for congestion, blackheads and oily or breakout-prone skin. Often more comfortable for that purpose than an AHA.
Barrier & hydration
Hyaluronic acid
A humectant that binds water to hydrate the skin's surface. Genuinely good for plumping hydration, but it's a moisturising ingredient, not an "anti-ageing" treatment in the way it's often marketed.
Ceramides
Lipids that occur naturally in the skin barrier. Replenishing them in a moisturiser helps support a healthy barrier and reduce moisture loss — useful for dry or sensitive skin.
Glycerin & squalane
Two reliable, low-drama hydrators. Glycerin is a humectant (draws in water); squalane is a lightweight emollient (softens and smooths). Both are well-tolerated and common in good moisturisers.
Peptides
Short chains of amino acids used as "signalling" ingredients. A broad category — evidence varies a lot depending on the specific peptide, so treat sweeping anti-ageing claims with some caution.
Sun care & label terms
SPF, UVA & broad spectrum
SPF measures protection against UVB (burning). UVA protection — linked to longer-term skin ageing — is shown by the UVA-in-a-circle logo, PA ratings or star ratings. "Broad spectrum" means a product covers both. See our sunscreen guide.
Mineral vs chemical filters
Two ways sunscreens block UV. Mineral filters (zinc oxide, titanium dioxide) sit on the skin; chemical filters absorb UV. Both are effective — the best one is the one you'll happily apply generously every day.
"Fragrance" / "parfum"
A common cause of irritation for sensitive or reactive skin, which is why many sensitive-skin ranges leave it out. It isn't inherently harmful for everyone, though — plenty of people use fragranced products with no issue.
"Non-comedogenic" & "hypoallergenic"
Marketing terms rather than tightly regulated standards. They can be a helpful steer, but they're not a guarantee — your own skin is the real test.
Most routines need only a few of these
A gentle cleanser, a moisturiser with ingredients like ceramides or glycerin, a daily SPF, and — if you want them — one or two well-chosen actives. You don't need one of everything on this list, and a shorter routine you stick to beats a long one you don't.