The Ordinary Niacinamide 10% + Zinc 1%: The Complete Guide

If there is one The Ordinary product that consistently sits in more skincare routines than any other, it is the Niacinamide 10% + Zinc 1%. It is one of the brand's original 2016 formulations, it has never been discontinued, and it has accumulated over 2,700 reviews with a 4.4-star average. For good reason.

But niacinamide is also misunderstood in a way that few skincare ingredients are. People use it for oil control without realising it also brightens. They use it for brightening without realising it also strengthens the skin barrier. And plenty of people use it alongside Vitamin C without knowing there is a real and well-established conflict there.

This guide covers everything: what niacinamide actually does and why, the three niacinamide products in The Ordinary range, exactly where it sits in your routine, what to pair it with, what to keep away from it, and how the Skincare Routine app handles the complexity for you automatically.

What is niacinamide?

Niacinamide is a form of Vitamin B3 — specifically the amide form of niacin (also called nicotinamide). It is water-soluble, which means it sits well in lightweight serums and absorbs quickly into the skin. Unlike some actives that need to be converted before they become active, niacinamide is immediately bioavailable from topical application — the skin can pick it up and use it directly from the moment you apply it.

It is also unusually well-studied. Niacinamide has decades of published research behind it covering everything from barrier function to hyperpigmentation to sebum regulation. This is not a trendy ingredient that arrived with little evidence behind it — it arrived in the 1990s as a research topic and has been accumulating clinical data ever since.

What is Zinc PCA?

The Ordinary's most popular niacinamide formula pairs it with Zinc PCA — zinc salt of pyrrolidone carboxylic acid. PCA is a naturally occurring compound found in the skin's own natural moisturising factors (the NMF), so it is inherently well-tolerated.

The zinc component is the important one here. Zinc has well-established sebum-regulating and mild anti-inflammatory properties of its own. It also serves a functional purpose in the formulation: Zinc PCA improves the delivery of niacinamide into the skin, helping the active reach where it needs to be more effectively. It is not just there to add a second bullet point to the product name — it earns its place.

What niacinamide actually does

Here is why niacinamide is genuinely worth the hype: it addresses multiple distinct skin concerns through different mechanisms simultaneously. Most actives do one or two things well. Niacinamide does five or six.

1. Reduces visible pore size

Niacinamide supports the skin's natural renewal process and helps regulate the production of sebum — the oil made by sebaceous glands. When excess sebum is produced, pores become visibly enlarged (they stretch under the pressure of the oil inside them). By moderating sebum production over time, niacinamide allows pores to contract back toward their natural size. Clinical testing on The Ordinary's 10% formula showed a measurable reduction in pore visibility after just four weeks of daily use.

2. Controls excess sebum and shine

Related to the above, but distinct: the visible shine you get on your nose and forehead within a couple of hours of cleansing is a sebum production issue. Niacinamide reduces the rate at which sebaceous glands produce oil, which translates directly to less shine and a more matte appearance throughout the day. In the same clinical study, this effect was visible in as little as three days.

3. Brightens and targets dark spots

Niacinamide inhibits the transfer of melanin-containing vesicles (called melanosomes) from melanocytes to keratinocytes — the cells in the upper layers of the skin's surface. This is the mechanism by which post-inflammatory hyperpigmentation (dark marks left after spots), sun spots, and general uneven tone develop. By interrupting this transfer, niacinamide gradually fades existing dark spots and prevents new ones from forming. Multiple independent clinical studies have confirmed this effect.

This is a completely different mechanism to how Alpha Arbutin works (which inhibits tyrosinase, an enzyme in the melanin production process itself) — which is why the two work well together for brightening goals.

4. Strengthens the skin barrier

The skin's barrier is primarily a lipid structure made up of ceramides, fatty acids, and cholesterol. Niacinamide supports the production of ceramides and fatty acids in the skin — the same key components that are found in the Natural Moisturizing Factors and that decline with age, exposure to harsh cleansers, and over-exfoliation. A stronger lipid barrier holds onto water more effectively and defends better against environmental irritants. This makes niacinamide particularly useful for people with sensitive, reactive, or over-stripped skin.

5. Reduces redness and inflammation

Niacinamide has a calming, anti-inflammatory action: it measurably reduces the production of pro-inflammatory cytokines in the skin. This is why it helps with redness associated with rosacea, post-blemish marks, and general irritation from other actives. If you are using retinoids or acids and experiencing some reactivity, adding niacinamide to your AM routine can help buffer that.

6. Supports collagen and reduces fine lines

Niacinamide supports the skin's natural synthesis of proteins and supports cellular repair pathways that tend to slow with age. Over longer periods of consistent use, this can contribute to a visible improvement in skin firmness and a reduction in the appearance of fine lines. It is not the primary reason most people use niacinamide, but it is a real bonus.

The clinical evidence: what to expect and when

The Ordinary's clinical testing on Niacinamide 10% + Zinc 1% used 35 subjects applying the serum twice daily for 8 weeks:

Within 3 days: Visible reduction in excess oil
After 7 days: Visible improvements in skin smoothness and radiance
After 4 weeks: Measurable reduction in pore visibility
After 8 weeks: Improved skin brightness, smoothed texture, strengthened barrier

These timelines matter because niacinamide is often written off by people who used it for two weeks, saw no dramatic transformation, and moved on. It is a slow-build, long-term ingredient. The oil control starts almost immediately. The brightening and barrier benefits take weeks to months to fully reveal themselves.

The Ordinary's three niacinamide products

The Ordinary currently offers niacinamide in three distinct formulations, each targeting a slightly different use case.

Niacinamide 10% + Zinc 1%

Best for: Oily, blemish-prone, and combination skin types. Anyone targeting pore visibility, oil control, brightening, or uneven skin tone.

This is the original — and for most people the most relevant product in the range. The 10% concentration is where the evidence is strongest. The Zinc PCA synergises with it on oil control and delivery. It is a water-thin serum that layers effortlessly, sits early in the routine, and is compatible with AM, PM, or both.

It is also, rather remarkably, one of the most affordable effective skincare serums available anywhere. At its current price point, there are moisturisers that cost more and deliver less.

One note on the 10% concentration: some people worry it is too high. It is not. The clinical evidence is based on 10% concentrations, and the formula is not inherently irritating the way acids or retinoids are. If you experience any tingling or redness when you first start, reduce to once daily for a couple of weeks before moving to twice daily.

Niacinamide 5% Face and Body Emulsion

Best for: Sensitive skin, body use, anyone who wants a gentler introduction to niacinamide on the face.

A newer formulation offering niacinamide at half the concentration in an emulsion format. The 5% concentration makes it better suited to sensitive skin and is the one to choose if you want to address dark spots on the body (shoulders, chest, arms) as well as the face. The emulsion texture is also thicker and more hydrating than the serum, which makes it a good option for dry skin types who find the 10% serum too watery on its own.

Soothing & Barrier Support Serum

Best for: Very sensitive, reactive, or compromised skin. Anyone whose skin is recovering from barrier damage.

This formulation contains only 2% niacinamide alongside Vitamin B12, a ceramide complex, and Centella asiatica phytotechnologies — a range of actives focused specifically on barrier repair and soothing. The niacinamide here is a supporting player rather than the headline ingredient. This is not the product to reach for if you want the full benefit of niacinamide; it is the product to use when your skin is too reactive for a higher-concentration formula, or when barrier repair is the urgent priority.

How to use niacinamide in your routine

Niacinamide 10% + Zinc 1% is a water-based serum, which means it belongs at the serum step — after cleansing and any toners or essences, before oils, moisturisers, and SPF.

Within the serum step itself, apply it before any anhydrous (oil-free) serums such as retinoids or oil-based actives. If you are using it alongside other water-based serums like Alpha Arbutin or Hyaluronic Acid, start with the most watery formula and layer from there. In practice, a few drops of niacinamide serum applied to the whole face is usually the first serum step for most routines.

How much: A few drops is genuinely enough for the whole face. More product does not mean more benefit.

Frequency: Daily is ideal. It is not an exfoliant or a chemical active that requires days off — it is a supportive, non-irritating ingredient that works best as a consistent part of your routine.

AM or PM? Both are fine. Many people prefer the AM for the sebum-control benefits — getting that effect working before the day starts makes more practical sense. But there is no restriction on using it twice daily if you want to, and the pipeline schedule also depends on what you use in your PM routine.

The one rule that matters: AM vs. PM is about Vitamin C

Niacinamide is compatible with the vast majority of actives in The Ordinary range. It plays nicely with retinoids, acids, peptides, and hyaluronic acid. There is, however, one conflict that is both important and commonly misunderstood.

DECIEM's guidance is: do not use Niacinamide 10% + Zinc 1% in the same routine as any Vitamin C product — direct or derivative.

What this means in practice

Direct Vitamin C — L-Ascorbic Acid Powder, Vitamin C Suspension 23% + HA Spheres 2%, Vitamin C Suspension 30% in Silicone — should not be used in the same routine as niacinamide. When pure L-Ascorbic Acid (which has a low pH of around 2.5–3.5) is applied alongside niacinamide, the acidic environment converts niacinamide to nicotinic acid. Nicotinic acid delivers fewer skincare benefits than niacinamide and can, at higher concentrations, cause temporary flushing and redness. You also effectively waste both products.

Derivative Vitamin C — Ascorbyl Glucoside Solution 12%, Magnesium Ascorbyl Phosphate, Ascorbyl Tetraisopalmitate 20% — is far more stable and gentler, but DECIEM still advises against using it in the same routine as niacinamide. The evidence for derivative forms causing problems is weaker than for pure L-Ascorbic Acid, but if you want to follow the brand's own guidance, keep all Vitamin C forms in a separate routine.

The practical solution: Use Niacinamide in your AM routine and keep your Vitamin C (in any form) in your PM routine. This is a clean, easy-to-follow split, and it means you get the full benefit of both ingredients.

What to pair niacinamide with (and why these combinations work)

Once you accept the Vitamin C rule, niacinamide is genuinely one of the most compatible ingredients in the range. Here are the most useful pairings.

Niacinamide + Alpha Arbutin 2% + HA

If brightening and dark spot reduction are your primary goals, this is one of the best pairings available at any price point. Alpha Arbutin inhibits tyrosinase (the enzyme that drives melanin production), while niacinamide blocks the transfer of formed melanin to the skin's surface. They attack hyperpigmentation at two separate stages of the same process. Both are water-based, both suit the AM serum step, and there are no conflicts between them.

Niacinamide + "Buffet" Multi-Peptide Serum

A combination that was specifically highlighted by DECIEM as a pairing for signs of ageing. Niacinamide handles barrier support and oil control while "Buffet" targets collagen synthesis and elastin. Together, they cover a wide range of anti-ageing concerns in a two-serum AM routine that leaves plenty of room for a moisturiser and SPF. No conflicts, fully compatible.

Niacinamide + Hyaluronic Acid 2% + B5

A straightforward but powerful duo. Hyaluronic acid draws moisture into the skin; niacinamide strengthens the barrier that holds it there. Apply HA first (to damp skin, before it dries), then niacinamide, then moisturiser to seal everything in. If you have dry or dehydrated skin, this is a reliable foundational pairing.

Niacinamide + Azelaic Acid Suspension 10%

A particularly good combination for anyone dealing with both blemishes and post-blemish marks simultaneously. Azelaic acid is a gentle, multi-functional active that targets congestion and redness at a low pH; niacinamide addresses the marks and oil control. They work on different aspects of the same problem. Apply niacinamide first (more watery), then Azelaic Acid Suspension (which is a thicker cream-gel formulation). Apply before heavier serums.

Niacinamide + Glycolic Acid 7% Exfoliating Toner

This might surprise some people. Exfoliating acids and niacinamide are fully compatible — there is no conflict. In fact, for uneven skin tone, pairing a mild exfoliant with niacinamide's brightening mechanism is effective: the acid sloughs away the surface layer of dull, dead cells while niacinamide addresses the pigmentation underneath. Use the Glycolic Acid Toner immediately after cleansing, let it dry, then follow with niacinamide serum.

Niacinamide + Retinoids

Also compatible — and also a surprise to many people who assume all actives need to be separated. You can use niacinamide and retinoids in the same routine (in the correct order: niacinamide first as it is water-based, retinoid second as it is typically oil-based). Some people even find that using niacinamide before their retinoid helps buffer the skin and reduces the dryness that retinoids can cause, particularly when starting out. That said, given the AM/PM scheduling that makes most sense (niacinamide in the AM, retinoids in the PM), you would often use them in separate routines anyway — not because they conflict, but because it is tidier.

Full AM and PM routine examples

Example AM routine: oil control and brightening

Cleanser
Hyaluronic Acid 2% + B5 (to damp skin)
Niacinamide 10% + Zinc 1%
Alpha Arbutin 2% + HA
Natural Moisturizing Factors + HA
SPF

This uses two of the three available serum slots. If you wanted to add "Buffet" for anti-ageing support, you could swap out Alpha Arbutin (if brightening is less urgent) or use Buffet as your third serum.

Example AM routine: anti-ageing focus

Cleanser
Hyaluronic Acid 2% + B5 (to damp skin)
Niacinamide 10% + Zinc 1%
"Buffet" Multi-Peptide + HA Serum
Argireline Solution 10% (optional; targets expression lines)
Natural Moisturizing Factors + HA
SPF

Example PM routine (with retinoid)

Cleanser
Hyaluronic Acid 2% + B5
Niacinamide 10% + Zinc 1%
Granactive Retinoid 2% Emulsion (or Retinol 0.2%)
100% Plant-Derived Squalane
Natural Moisturizing Factors + HA

Note: If you are including Vitamin C in your PM routine (which many people do, since the AM slot is taken by niacinamide), keep the Vitamin C on a separate evening from the nights you use niacinamide. An easy pattern: Vitamin C PM on the nights you don't use retinoids; retinoids and niacinamide PM on alternating nights.

Example PM routine: brightening, no retinoids

Cleanser
Glycolic Acid 7% Exfoliating Toner (2–3 nights per week)
Niacinamide 10% + Zinc 1%
Azelaic Acid Suspension 10%
Natural Moisturizing Factors + HA

On the evenings you don't use the glycolic toner, you can simply start at step 3.

How the Skincare Routine app manages niacinamide for you

Keeping track of the Vitamin C rule, the layering order, the three-serum limit, and the AM/PM scheduling is exactly the kind of cognitive overhead that makes skincare feel overwhelming. The Skincare Routine app is built to remove that overhead entirely.

Niacinamide 10% + Zinc 1% is pre-loaded

Every The Ordinary product — including Niacinamide 10% + Zinc 1%, both HA serums, Alpha Arbutin, all peptide serums, and every retinoid — is already in the app with its correct layer position, time-of-day setting, and full conflict rules. You add it to your routine; the app places it in the right step automatically.

Vitamin C conflicts flagged in real time

If you tick Niacinamide 10% + Zinc 1% and then go to tick any Vitamin C product in the same session, the app shows a red checkbox on the Vitamin C entry — a hard conflict. You can see exactly why the conflict exists with a single tap. No more guessing whether derivative Vitamin C counts (it does, per DECIEM).

Auto-sorted layering order

Add niacinamide and Alpha Arbutin to the same routine and the app places niacinamide first (slightly more watery formulation). Add a retinoid alongside it and the retinoid goes in the correct position after the water-based serums. The ordering algorithm is based on DECIEM's own guidance. You can also reorder manually if you have a reason to.

Never exceed three serums

The app counts serums and warns you if you have added more than three to a single routine session — following DECIEM's recommendation not to overload the skin. If you have Niacinamide, Alpha Arbutin, and "Buffet" in your AM routine, you are at the limit. Adding a fourth serum will prompt a warning.

See when you last used each product

For people who rotate niacinamide with Vitamin C across different evenings, the six-day usage bar shown beneath each product lets you see at a glance which products you used in recent sessions — no mental tracking required.

Track whether your skin is improving

After each completed routine, you can rate how your skin looks and feels. Over weeks of consistent niacinamide use, the daily rating builds a log that makes it easy to see when improvements in oil control, smoothness, or brightness actually began — and whether they correlate with adding niacinamide to your routine.

The app is available at skincareroutine.app and on the App Store and Google Play.

Summary: niacinamide at a glance

Product	Concentration	Format	Best for	Conflicts
Niacinamide 10% + Zinc 1%	10%	Water serum	Oily/blemish-prone skin, brightening, pore size	All Vitamin C (direct and derivative)
Niacinamide 5% Face & Body	5%	Emulsion	Sensitive skin, body, gentler brightening	All Vitamin C (direct and derivative)
Soothing & Barrier Support Serum	2%	Light cream	Very sensitive skin, barrier repair	All Vitamin C (direct and derivative)

Layer position: After toner/essence, before oils and moisturisers. Water-based serums first within the serum step.

When: AM preferred for sebum control; AM + PM also fine. Keep separate from any Vitamin C routine.

Patience required: Oil control from day 3. Visible pore reduction at 4 weeks. Full brightening benefits at 8+ weeks.

Niacinamide is one of those rare skincare ingredients that genuinely earns the word "essential." It does not demand the cautiousness of a retinoid, the careful scheduling of a peel, or the stability considerations of Vitamin C. It simply works — quietly and consistently — on several concerns at once. Run it every morning, respect the one meaningful conflict, and let it do its job. The Skincare Routine app will keep the rest organised.