Niacinamide: what the percentage means, and why you can use it with vitamin C

This page contains affiliate links. MoreThanMy earns a commission on qualifying purchases, at no extra cost to you.

Researched. We have not used this one long enough to give you a verdict, and we would rather say so than invent one. What follows is how it works, who it suits, and what it will not do. When we have used it properly, this page carries the verdict and the date.

The Ordinary Niacinamide 10% + Zinc 1%

Niacinamide is vitamin B3. It is water-soluble, cheap, stable in a way most interesting skincare ingredients are not, and in almost everything you own whether or not you bought it for that.

It is also an amide — the same vitamin as niacin, with a different group hanging off the end of the molecule. That detail is dull, and it is the entire basis of the vitamin C argument, so it is worth parking for a moment.

Why the claim list is so long

Niacinamide sits upstream. Inside a cell it feeds into a pair of coenzymes that a great many ordinary metabolic reactions depend on, which means it is not doing one thing to your face. It is nudging a lot of processes slightly.

That explains the odd shape of its reputation. It is credited with helping the barrier, evening out tone, calming redness and controlling oil, and the reason four unrelated claims sit on one box is not that the marketing department got greedy. An upstream ingredient genuinely touches all of them a little.

So read the length of that list as information about breadth, not force. Salicylic acid does one thing and you can feel it working. Niacinamide does several and you will feel none of them. Neither is a criticism.

The number on the front of the bottle

Most products sold as niacinamide sit between low single figures and ten percent, with a small tier marketed higher. Below that range it is still very often present, holding up a moisturizer that never prints the figure anywhere.

So the percentage on the front tells you what the product is marketed on.

Five percent versus ten

The response is not a straight line, and the irritation curve is steeper than the benefit curve. Somewhere past the middle of the range you are mostly buying more of the thing that makes a minority of people flush, and not much more of the thing you wanted.

Where your own line falls is not knowable in advance, and the strongest one on the shelf is the most expensive way to find out you are one of the people who reacts. If you have never used niacinamide deliberately, start below ten. If you have been using it uneventfully for months — and you probably have, without choosing to — ten is a reasonable place to stand rather than a place to aim for.

And what separates a five percent product from a ten is usually not the niacinamide — it is the texture, the acidity and the other actives riding along. Two bottles with the same number on the front can behave nothing alike.

The vitamin C claim, and where it came from

The rule you have read is that niacinamide and vitamin C cancel each other out, or combine into something that makes you flush. It comes from real laboratory chemistry. It also does not describe what happens when you put one on your face and then the other.

Two things were observed. In plain water, with heat and time, niacinamide can hydrolyse back into nicotinic acid — the form of B3 that causes flushing. And niacinamide and ascorbic acid in solution together can form a complex, which shows up as a colour change.

Both are true, and both were observed under conditions your bathroom does not reproduce. The condition doing the work is heat, sustained, and for far longer than a morning; at skin temperature the hydrolysis is slow enough to be beside the point. Be careful with the obvious defence here, because it runs the wrong way: the low pH a vitamin C serum is built around speeds amide hydrolysis up rather than holding it back. What keeps the reaction negligible is the temperature and the number of minutes involved, not the clever formulating.

The two meeting on your face for a morning is not that experiment.

Now the part where it is easy to overclaim in the other direction. None of that promises your particular pair will agree with you. A good L-ascorbic acid serum is acidic by design, niacinamide is a thing some people flush from, and layering two actives is two chances to irritate. If you use both on one morning and your face goes hot, you have learned something specific about those two bottles and nothing general about chemistry.

The fix does not require you to be right about the mechanism. Put one in the morning and one at night and the question stops existing. Which step goes where covers the rest of that arithmetic.

The real problem is that it is in everything

Nobody decides to use four niacinamide products. People arrive there by buying four good products.

It is in cleansers, toners, serums, moisturizers, sunscreens and plenty of foundations, because it is cheap, stable, and gives a copywriter something true to say. Build a routine out of well-reviewed things and you can be applying it several times before breakfast without once having chosen to.

So the figure you chose and the amount arriving on your face are two different numbers, and the second one is the one deciding how the ingredient behaves for you. That is the most common reason someone concludes niacinamide does not agree with them. Often it agrees fine at the amount they thought they were using.

So before you buy anything to fix a face that has started stinging for no reason you can name, read the backs of the bottles you already own — the same ingredient-list reading we ran on PDRN, pointed the other way.

What the barrier claim is worth

This is the best-supported of the four. The barrier is the outer layer of skin, and what makes it work is lipid — the oily mortar between the cells that holds water in and keeps irritants out. Niacinamide has a genuine and reasonably well-studied role in how skin produces those lipids. Less water escapes, and skin that loses less water is calmer and considerably harder to annoy.

In practice: less redness, less tightness, better tolerance of the harsher steps in a routine.

It is not a moisturizer, though. It is a water-soluble ingredient in a water-based product and it seals nothing. If your skin is dry, the humectant and occlusive distinction is the answer, not this.

And the oil claim

Thinnest of the four. There is real work behind it, but the effects are modest and vary a great deal between people. The honest ceiling is "less shiny by the afternoon", not a change in how oily your skin is.

Zinc, usually as zinc PCA, tends to ride along in the same bottles on the same claim, and it arrives with the same modest ceiling. It is on the label because the two are sold together, and there is little published work setting the pair against niacinamide on its own.

If the complaint is congestion — the small bumpy patches around the nose and chin — that is a different tool, and what a BHA actually does is the better page.

Who it suits

Probably yes if your skin is easily annoyed, if the barrier has taken a beating from acids or a retinoid, or if you want one dependable background ingredient rather than another thing to schedule.

Probably not if you flush easily. A minority of people react to niacinamide with warmth and pinkness that has nothing to do with what it is mixed with. If that is you, a lower percentage may be no kinder, and it is not a thing to work up to. Try it once further down if you want the ingredient badly enough; if it still goes pink, that is your answer and it is a perfectly good one.

What it will not do

• It will not make pores smaller. Pore diameter is largely structural. What changes is how much shadow sits in one, which is a real improvement and a different sentence.
• It will not fix pigment on its own. It has a plausible role in how pigment moves between cells, but on marks and uneven tone it is a supporting player — see kojic acid and the brightening claims, and buy the sunscreen either way.
• It will not rescue a routine that is irritating your skin. It makes irritation more survivable, which is not the same thing, and is exactly how people end up running an over-aggressive routine for a year.
• It will not do anything you can see this week. How long to give a product matters here more than almost anywhere, because there is no sting and no peel to mistake for progress.

How you will actually know

You probably will not notice niacinamide working. That is not a failure of the ingredient. It is what a background ingredient looks like from the inside.

The only reliable way to find out whether it is doing something for you is to take it out and see whether anything gets worse. It is an unglamorous test, it takes weeks, and it beats any before-and-after you will be shown.

The product

It is the ten, which is the number this page spent a section declining to treat as a default. It is here because it is the one people are searching for, because the label is plain — two ingredients on the front, both with numbers, and no story attached — and because if you are going to find out where your own line falls, this is a cheap way to find out. The zinc is along for the ride on the oil claim, which is the thinnest of the four. If you have never used niacinamide deliberately, a lower percentage is the more sensible first bottle.

The one people are searching for is the The Ordinary Niacinamide 10% + Zinc 1%.

The Ordinary Niacinamide 10% + Zinc 1%

We do not print prices here, because a price we typed last month is a price that is wrong today.

Written by JamieG in Garner Town, Tennessee.