Retinols

Start low. SkinCeuticals Retinol 0.3, iS Clinical Retinol+ Emulsion 0.3 and Medik8 Crystal Retinal 3 are all sensible first steps.

Use it once or twice a week to begin with and build up as your skin tolerates it. Strength matters far less than sticking with it, and going in too strong is the most common reason people give up.

Both are forms of vitamin A. Retinal, or retinaldehyde, is one conversion step closer to the active form, so it tends to work faster at a comparable strength.

Medik8 Crystal Retinal, Murad Retinal ReSculpt and Allies of Skin Retinal 0.1% are retinals. Obagi Retinol, SkinCeuticals Retinol and Reform Skincare Retinol are retinols. Neither is better as such: retinal is quicker, retinol is often gentler.

Some dryness, flaking and the odd spot in the first few weeks is common as cell turnover speeds up, and it usually settles by around week six.

Stinging, burning or persistent redness is not normal. If that happens, stop, let your barrier recover, then go back in at a lower strength or less often.

At night, on dry skin, after cleansing. Wear a broad spectrum SPF the following morning without exception, since retinol makes skin more vulnerable to UV.

Keep strong acids for a different evening while you are building tolerance. Vitamin C, niacinamide and peptides all sit comfortably alongside retinol.

Usually yes, with the right approach. Start at the lowest strength, apply twice a week, and buffer it by mixing it with your moisturiser or applying moisturiser first.

Encapsulated and slow release formulas tend to be better tolerated. If your skin is actively irritated, settle the barrier first and introduce retinol once it is calm.

Texture and brightness usually improve within four to six weeks. Fine lines and firmness take twelve weeks or more, because that is how long collagen takes to build.

Retinol rewards consistency over strength. Three nights a week for a year will do more than every night for a fortnight.