Niacinamide, and why it is in everything.
Vitamin B3. It supports the barrier, it takes some of the edge off oil and visible redness, and most skin tolerates it without a fuss. It is also in your cleanser, your moisturiser, your serum and your sunscreen at the same time — which turns out to matter more than the percentage printed on the front.
Vitamin B3, doing several small things at once.
Niacinamide is the amide form of vitamin B3. You will also see it written as nicotinamide; they are the same thing. It is water-soluble, it is stable, and it works across the range of formulation acidity that most products sit in.
That combination is unusual, and it explains the rest of this page. Niacinamide is not an acid and not an exfoliant. It does not thin the surface of the skin, it does not need to be introduced slowly, and it does not degrade in the bottle the way vitamin C does. It is cheap to make and difficult to get wrong. So it went into everything.
What it does not do is one dramatic thing. It does several modest ones, most of which come back to the same mechanism — it supports the skin’s own production of the lipids that hold the barrier together. Skin that holds water better is behind most of what people notice, and most of what they notice takes weeks.
Five things it is used for.
Listed in the order the evidence supports them, strongest first. Skin varies enormously, and none of these arrive on any particular face just because they arrived on someone else’s.
- Barrier support
- The best-established use and the least interesting to read about. Skin holds water better, which over a few weeks tends to show up as less tightness, less stinging when other products go on, and a face that reacts to fewer things. This is why niacinamide lives in moisturisers rather than only in serums.
- Oil and shine
- A moderate effect on how oily skin looks by the end of the day. Moderate is the honest word — it is a difference some people see clearly and others do not see at all. It is not a substitute for treating congestion properly, and it will not change how much oil skin is inclined to make.
- How red skin looks
- Skin that is reactive often looks less red over several weeks of use, largely because it is less reactive rather than because anything was removed. That is a change in appearance. Persistent facial redness has named causes, naming one is a doctor’s job, and no ingredient on a shelf treats a condition it has not identified.
- Uneven tone
- Niacinamide interferes with pigment being handed on to surface cells. That makes it a slow and partial contributor rather than a fix, it does very little about pigment already sitting deeper, and sun protection does more for uneven tone than anything else you can buy. Useful in a plan; disappointing on its own.
- The appearance of pores
- The most heavily marketed claim and the weakest of the five. There is some evidence, it is modest, and pore size itself does not change. If this is the reason you are buying it, expect very little.
Nothing here is a treatment for a diagnosed skin condition. If something on your face needs a name, that is a GP, and we will say so rather than hand you a serum.
Higher is not better.
Most of the research people cite when they sell niacinamide sits between two and five per cent. The ten and twenty per cent products that dominate the shelf are a marketing position rather than an evidence position, and the number on the front is doing sales work that the ingredient inside is not.
Past about five per cent, the thing you reliably gain is a higher chance of stinging. Tightness, a warm flush on application, occasional low-grade irritation — more common at high concentrations, and considerably more common on skin already running acids or a retinoid.
There is also no way to verify the number. Percentages are not required on a label and are not audited.
The practical consequence is worth saying plainly. If a strong product stung and you concluded that niacinamide does not suit your skin, you may only have concluded that ten per cent does not. That is a different and much smaller finding.
It plays well with almost everything.
This is where niacinamide earns its reputation. It does not need low acidity to work, and it is one of the few actives that can join a routine without a plan for introducing it.
The vitamin C warning is out of date. It traces to old laboratory work where niacinamide and ascorbic acid, held together under heat in unstable conditions, could convert to niacin — which causes flushing. A finished formulation on a face is not those conditions. Products deliberately contain both. If the pairing stings on you, the acidity of the vitamin C is the usual culprit, and using one in the morning and one at night settles it.
With a retinoid it is often deliberate. Nothing about niacinamide cancels out retinol, retinal, or a prescription retinoid your doctor has prescribed. The barrier support is precisely why it gets formulated alongside them.
The real stacking problem is quantity, not compatibility. Niacinamide is now in cleansers, moisturisers, serums, sunscreens and foundations. It is entirely normal to be using four sources of it without knowing, and that is where most of the “my skin hates niacinamide” stories come from. Read the back of what you already own before you buy a fifth.
A good supporting act, rarely the lead.
Almost nobody’s skin changes because of niacinamide. It makes other things more tolerable, it helps a barrier hold, and it takes a slight edge off oil and off how red skin looks. Those are real and worth having. They are not a transformation, and a page that implies otherwise is selling.
If your routine has no sunscreen, niacinamide is not the gap. Sunscreen has the strongest evidence of anything you can buy and the least glamour attached to it. Nothing else on the shelf works as well without it.
And if the moisturiser you already own contains it, a dedicated serum often adds very little. For a reasonable number of people the honest answer is that they have been using niacinamide for two years and are about to pay for it a second time. We would rather tell you that than sell you the serum.
Where it genuinely earns its place is narrower: skin that reacts to everything, skin recovering from over-exfoliating, and skin that needs to tolerate something stronger than it currently can. There the supporting role is exactly the point.
Asked about niacinamide.
Answered the way they would be answered in the room.
What does niacinamide do for your skin?
Niacinamide is vitamin B3. Its best-established effect is supporting the skin barrier, which over several weeks usually shows up as skin that feels less tight and stings less easily when other products go on. It has a moderate effect on how oily skin looks through the day, and reactive skin often looks less red. It also slows the transfer of pigment to surface cells, making it a slow and partial contributor on uneven tone. None of that is dramatic on its own, and it is not meant to be.
What percentage of niacinamide should I use?
Most of the research people cite sits between two and five per cent. The ten and twenty per cent products are a marketing position rather than an evidence position. Past about five per cent, the thing you reliably gain is a higher chance of stinging and tightness, particularly if you already use acids or a retinoid. There is also no way to verify the number from outside the bottle. If a strong product stung and you decided the ingredient does not suit you, try a lower concentration before ruling it out entirely.
Can you use niacinamide with vitamin C?
Yes, and the warning against it is out of date. It traces back to old laboratory work in which niacinamide and ascorbic acid, held together under heat in unstable conditions, could convert to niacin, which causes flushing. A finished modern formulation sitting on a face is not those conditions, and plenty of products contain both on purpose. If the pairing stings on your skin, the acidity of the vitamin C is the more likely culprit than any interaction, and using one in the morning and the other at night solves it.
Can you use niacinamide and retinol together?
Generally yes, and they are often paired deliberately. Nothing about niacinamide cancels out a retinoid, and the barrier support is the reason it gets formulated alongside one. What matters more is total load. Skin that is already dry and flaking from a retinoid does not need two more products introduced in the same fortnight. Add one thing, give it several weeks, and only then decide whether anything else is needed. Most routines that go wrong go wrong through speed rather than through the wrong ingredient.
Can niacinamide cause breakouts or irritation?
It can irritate, although it is one of the actives most skin tolerates easily. The two usual reasons are concentration and repetition. High percentage products sting more often than moderate ones. And niacinamide now sits in cleansers, moisturisers, serums, sunscreens and foundations, so using four sources at once without realising is common. Purging is not something niacinamide is known for, because it does not accelerate turnover the way an exfoliant or a retinoid does. Stripping back to one product containing it is the cheapest way to find out what is happening.
How long does niacinamide take to work?
Weeks rather than days, and comfort changes before anything visible does. Skin that felt tight or stung with everything may feel steadier within two to four weeks. Changes in how oily or how red skin looks are slower and less predictable, and tend to be described over eight to twelve weeks. Effects on uneven tone are slower again and partial. If nothing at all has shifted after three months of consistent use, stopping is a reasonable decision rather than a failure of patience.
Can you use niacinamide during pregnancy?
It is commonly one of the ingredients kept in a routine while others are set aside, and it is a frequent stand-in for the actives that get paused. That said, we do not make that call from a web page. Pregnancy changes what is appropriate across a whole routine rather than one product at a time, and the people to confirm it with are your GP or midwife and the nurse who can see everything else you are using. Bring the actual bottles to that conversation rather than a list from memory.
Knowing what it is does not tell you whether you need it.
That depends on what your skin is doing, what you already own, and what you will realistically keep up — none of which a page can know about you.
Eight ingredients with real evidence behind them, each with one honest limit attached.
Redness and broken capillariesWhat reactivity is, what a visible vessel is, and why the two need different answers.
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What the clinic stocksA short range rather than a wall. If the right product for you is one we do not sell, we will say where to buy it.