Skincare Ingredients

Allantoin softens rough, flaky skin and soothes irritation, and the US FDA recognizes it as a skin protectant. Here is how it works, what the research shows and how to use it.

Arbutin slows the enzyme your skin uses to make pigment, so dark marks fade as your skin turns over. Here is what it does, who it suits, how to read the label, and how long to give it.

Azelaic acid treats breakouts, redness and the dark marks left behind at the same time, and is gentle enough to use in pregnancy. Here is how it works and how to use it.

Bakuchiol is the alternative most people reach for when retinoids are off the table, including during pregnancy. Here is what the evidence supports and what to check first.

Benzoyl peroxide clears red, inflamed breakouts and keeps them from coming back, and bacteria never become resistant to it. Here is why 2.5 percent is the strength to start with.

Beta glucan holds water in your skin, calms irritation and supports healing after red, inflamed breakouts. Here is how it works, what the research found and where it fits in your routine.

Bisabolol is the calming compound first found in chamomile, and it quiets the inflammation behind redness, stinging and itch. Here is how it works, who it suits and how to use it.

Caffeine narrows the small blood vessels under your eyes, which helps morning puffiness settle and softens a bluish shadow. Here is how it works, and when it will not help.

A carboxy gel mask uses carbon dioxide to make your own blood deliver oxygen to the skin, so you get visible plumpness and glow within the hour. Here is how it works and when to use it.

Centella calms inflammation, helps skin hold on to water and supports repair after irritation. Here is what the research shows, what cica means on a label and how to use it.

Ceramides are half the mortar holding your skin together, and running low is why skin turns tight and reactive. Here is how replacing them repairs a struggling barrier.

Colloidal oatmeal calms itch and protects dry, eczema-prone skin while its barrier repairs. Here is how it works, what the trials found and how to tell it apart from oat extract on a label.

Ectoin holds water steady around your skin cells, so skin that reacts to wind, heat, flights and city air stays calm. Here is what the eczema trials found and how to use it.

Enzymes dissolve the bonds holding dead cells to your skin and then stop, which makes them the gentlest exfoliant there is. Here is how they work and who they suit.

Exosomes carry repair instructions between your cells, and they do their best work applied straight after microneedling or laser. Here is how they work and when they are worth it.

Gluconolactone is a PHA that smooths rough, dull skin and draws water in as it exfoliates. Here is how it works, what the research found, and how to use it if your skin is reactive.

Glutathione is the antioxidant your own cells make. What it does about everyday damage and uneven tone, and how to choose a product that still works when you open it.

Glycerin draws water into the outer layer of your skin and helps your barrier recover. Here is how it differs from the oils in your moisturizer, and what it does in very dry air.

Glycolic acid is the smallest exfoliating acid, so it reaches deepest and does the most for texture, tone and fine lines. Here is how to use it without overdoing it.

Green tea extract neutralizes the unstable molecules sun creates in your skin and calms redness. Here is what the studies found on oil and breakouts, and how to read a label for it.

Growth factors are the signals your skin uses to build collagen and repair itself, and you make fewer with age. Here is what a serum can do and how it compares to retinoids and exosomes.

Hyaluronic acid holds a thousand times its weight in water and plumps skin the same day. Here is how to apply it so it works, and why it sometimes backfires.

Hypochlorous acid kills bacteria and calms inflammation without irritating skin, which is why we use it on faces too upset for anything else. Here is how it works.

Kojic acid blocks the pigment enzyme by taking away the copper it needs, which makes it a strong partner for arbutin. Here is how to use it and why one percent is the number.

Lactic acid exfoliates and hydrates at the same time, which makes it the AHA for dry and easily irritated skin. Here is how it compares to glycolic and how to use it.

Licorice root slows the excess pigment behind dark spots and soothes redness on reactive skin. Here is how its compounds work, what the research shows and how to use it every day.

Mandelic acid exfoliates, slows pigment production and reduces acne bacteria all at once, which makes it the acid for post-breakout marks and deeper skin tones.

NAD+ powers cellular repair and declines sharply with age. The biology is solid, the delivery is the real question, and here is how to tell a serious product from a slogan.

Niacinamide calms redness, strengthens the barrier, evens pigment and regulates oil, all without irritation. Here is why four to five percent is the number and how it fits with everything else.

Panthenol is vitamin B5 in a form your skin absorbs. It hydrates, calms irritation and supplies material for barrier repair, all at once. Here is why it makes everything else easier to use.

PDRN is purified salmon DNA that switches on a repair receptor in your skin. Here is how it works, and the difference between a serum and the injectable treatments the research is based on.

Peptides tell your skin cells to build collagen, and they do it without any irritation. Here is what the different types actually do and how to read a peptide label.

Your skin is covered in bacteria doing useful work. Here is the difference between prebiotic, probiotic and postbiotic, and what supporting your microbiome actually does.

Resveratrol is an antioxidant from grapes and berries that helps protect your collagen and your glow from sun damage. Here is how it works, what the studies found and how to use it.

Retinoids build collagen, clear pores and fade pigment, with decades of research behind them. Here is how to read the labels and how to start without giving up in week three.

Salicylic acid dissolves in oil, so it gets inside pores where other acids cannot. Here is why that clears blackheads and congestion, and how to use it without drying yourself out.

Shea butter softens dry skin and slows the water loss that leaves it tight and flaky. Here is how it works, what the eczema research found and what to know about nut allergies.

Sodium hyaluronate is the salt form of hyaluronic acid, and usually the better choice. Here is why it is on the back of the bottle when the front says something else.

Squalane is the stable version of an oil your skin already makes, and it suits dry, reactive and acne-prone skin without clogging pores. Here is the one-letter difference that matters on a label and where it belongs in your routine.

Sulfur dries out breakouts, absorbs oil and calms inflammation, gently enough for rosacea-prone skin and pregnancy. Here is how it works and when it beats benzoyl peroxide.

Titanium dioxide is a mineral that sits on your skin and stops UV light reaching the cells underneath. Here is how it works, why it sometimes looks white, and how to use it properly.

Tranexamic acid quiets the signal that tells your skin to make pigment, and it calms the blood vessels that keep melasma coming back. Here is why it works when other brighteners do not.

Urea draws water into your skin and, at higher strengths, softens rough, thickened patches on your body. Here is how it works, where each strength is used and what the eczema research shows.

Vitamin C intercepts the daily damage from sun and pollution, fades dark patches and is required for your skin to build collagen. Here is how it works and which form suits your skin.

Vitamin E protects the fatty part of your skin barrier from sun and pollution damage, and it works best paired with vitamin C. Here is why that pairing matters, and why the research does not back putting it on a scar.

Volufiline targets the fat pads beneath your skin rather than the skin itself, which makes it unlike anything else in a routine. Here is how it works and what to realistically expect.

Zinc oxide is the only single sunscreen filter that covers the whole ultraviolet range, and it calms skin while it does. Here is how it works and how to wear it without a white cast.