The Glasskin Journal

AHA, BHA and PHA exfoliants: which one for your skin, and how often

AHA for the surface, BHA for pores, PHA for sensitive skin: how to choose a Korean chemical exfoliant, how often to use it, and the mistakes that damage the skin barrier.

Korean retinol: gentle doses and how to start without irritation

0.1% or 0.15%, two evenings a week, never with an acid, SPF the next morning: the Korean method for starting retinol without redness, with the precautions (pregnancy) and three gentle formulas.

Snail mucin: what the science says, and who should try it

Hydration, repair, radiance: what snail mucin really does, what studies show and do not show, the allergies to know about (dust mites, molluscs) and who the COSRX snail mucin serum suits.

Centella asiatica (cica): the Korean soothing active explained without the hype

Redness, reactive skin, post-acne marks: what centella asiatica really does, what the science shows (and does not yet show), and how to choose between a cica ampoule, serum and cream.

Niacinamide: what it really does and how to choose it (2%, 5%, 10%)

Sebum, pores, dark spots, skin barrier: what niacinamide actually does, the concentration at which it works, and why 10% is not necessarily better than 5%. Guide plus a Korean selection.

PDRN, collagen, peptides: are the new Korean actives really worth it?

PDRN, collagen and peptides are taking over K-beauty shelves. What the science really says about each, what to expect from them topically and how to add them to your routine.

Korean sunscreen: what makes it different (textures, filters, SPF 50+ PA++++)

Fluid textures, modern filters, high UVA protection: what sets a Korean sunscreen apart, how to read SPF and PA++++, how much to apply and when to reapply.

Double cleansing: why Korean women start with a cleansing oil

A cleansing oil dissolves SPF, sebum and make-up; a foam rinses the rest. The Korean double cleanse explained, with the right products for your skin type.

Hydrocolloid pimple patches: how they work and how to use them

A hydrocolloid pimple patch absorbs, protects and stops you picking. What it really does, which spots it works on, how to apply it and how long to leave it on.

Korean skincare routine for beginners: the 5 steps that actually matter

Forget the 10 steps. Today's Korean skincare comes down to five moves: cleanse, tone, target, moisturise, protect. The right order, morning vs evening, and the mistakes to avoid.