Niacinamide at 5%: why that number

Niacinamide is one of the few skincare actives with a specific number attached to it, and the number is 5%.

Then products arrive at 10% and 20%, marketed as stronger. They are more irritating, not more effective, and the reason is worth understanding, because it is the clearest example in skincare of a dose that is not linear.

This is information, not medical advice. Persistent redness, burning, or a rash after any product needs a dermatologist, particularly if you have been using an unidentified cream.

What it is

Niacinamide, also called nicotinamide, is a form of vitamin B3.

A naming point that causes confusion: it is not niacin (nicotinic acid). Niacin causes flushing; niacinamide does not. And oral nicotinamide is a different subject from the topical version discussed here, it has been studied for other purposes entirely, including skin cancer prevention in high-risk patients, which is a medical matter and not what a serum does.

In the skin it is a precursor to NAD+, a coenzyme involved in cellular energy and repair, which is the mechanistic basis for most of its claimed effects.

What the evidence supports

This is one of the better-evidenced cosmetic actives, and the claims are specific rather than vague.

Reasonably supported:

Barrier function. Niacinamide increases ceramide and free fatty acid synthesis in the skin, which strengthens the barrier and reduces water loss. This is the best-established effect and it underlies several of the others.

Pigmentation. It interferes with the transfer of melanosomes from melanocytes to keratinocytes, meaning it does not stop pigment being made, it reduces how much reaches the upper skin. Studies at around 5% have shown reduction in hyperpigmentation.

This mechanism matters for Indian skin specifically, because post-inflammatory hyperpigmentation after acne is the most common complaint here, and it sits exactly where niacinamide acts.

Sebum. Some evidence for reduced sebum production, relevant for oily skin.

Redness and blotchiness. Anti-inflammatory activity, with reasonable support.

Fine lines and texture, modestly.

Acne. Topical niacinamide has been studied in mild to moderate acne with some supporting data, including comparisons against topical antibiotics.

Less well supported: pore size, and most of the more dramatic “glow” claims.

Where 5% comes from

The number is not arbitrary. A series of studies through the 1990s and 2000s, a good proportion conducted by Procter & Gamble, which is worth noting, tested topical niacinamide at various concentrations and reported benefits on pigmentation, barrier function, sebum and the appearance of ageing, commonly at 2% to 5%.

5% became the reference concentration because that is where the bulk of the supporting data sits, with 2% also showing effect for some endpoints.

So when a label says 5%, it is aligning with the research. That is a legitimate thing to do and a reason to prefer it.

Why higher is not better

Three reasons, and they stack.

1. The evidence does not extend upward. There is no body of trials showing that 10% or 20% outperforms 5% for these endpoints. The concentration was chosen in the research and then exceeded by marketing, not by data.

2. Irritation rises. This is the practical problem. Higher concentrations cause more flushing, stinging, redness and dryness, and a sizeable proportion of people cannot tolerate 10% or 20% on the face.

And the specific flushing point: niacinamide can degrade to niacin (nicotinic acid) over time, particularly with heat, poor pH control or long storage, and niacin causes flushing. So a high-strength product that has degraded is both less effective and more likely to make your face go red. Some of the flushing attributed to niacinamide itself is actually this.

3. In Indian skin, irritation is counterproductive. This is the most important point for this market.

Inflammation drives pigmentation in darker skin types. So a product strong enough to irritate you is actively working against the thing you bought it for. Someone using 20% niacinamide for dark marks, getting redness and then more pigmentation, has a worse outcome than if they had used 5%.

That is the whole argument in one sentence: more is not stronger here, it is counterproductive.

How to use it

Concentration: 5%. Start at 2–4% if your skin is sensitive or reactive.

When: morning or night, or both. Morning under sunscreen works well, and it layers easily.

Order: after cleansing, before heavier moisturiser. It is water-soluble and goes on early in the routine.

Amount: a few drops for the whole face. More is not better.

How long: 8–12 weeks for pigmentation. Barrier improvements can be noticed sooner, within a few weeks.

Take photographs in consistent light. Pigmentation changes slowly and memory is unreliable.

The combination questions

These come up constantly, and most of the received wisdom is wrong.

With vitamin C, this is the myth worth correcting.

The old advice was not to combine them, based on the idea that they neutralise each other. This came from studies using high heat and unformulated raw ingredients, and it has largely been set aside. In properly formulated products at normal use conditions, combining them is generally fine, and many products contain both.

If you are cautious: vitamin C in the morning, niacinamide at night. It costs you nothing to separate them.

With retinoids, a genuinely good pairing. Niacinamide supports the barrier, which reduces the irritation retinoids cause. This is one of the more useful combinations in skincare, and it helps people tolerate retinoids they would otherwise abandon.

With acids (AHA/BHA), use at different times to limit irritation.

With sunscreen, essential, and particularly so if you are treating pigmentation. Without daily sunscreen you are treating and re-causing the same problem, and no serum overcomes that.

With azelaic acid, compatible, and a sensible combination for Indian skin because both work on pigmentation and acne.

Who should be careful

Sensitive or rosacea-prone skin, start low, and expect that even 5% may cause flushing in some people.

Anyone who has had a reaction, patch test behind the ear or on the inner forearm for a couple of days.

Pregnancy and breastfeeding, topical niacinamide is generally considered acceptable, and confirm with your doctor.

And the general rule in Indian skincare: stop any unidentified cream. Topical steroid misuse on the face is widespread in India, producing thinning, visible blood vessels, persistent redness and steroid-induced acne, and difficult to reverse. Any cream that clears skin within days deserves suspicion, and if the full composition is not printed on the label, it should not go on your face.

If you have been using one, do not stop abruptly, the rebound can be severe. See a dermatologist to come off it.

What it does not do

It does not lighten skin tone. It reduces excess pigmentation, dark marks, melasma, uneven patches. It does not and cannot change your baseline skin colour, and a product marketed on that basis is selling something different.

And we do not manufacture fairness or skin-lightening products, for reasons we have set out separately. Pigmentation is a dermatological matter; the fairness market is a different thing, and parts of it have a documented problem with undeclared steroids, hydroquinone and mercury.

It does not treat melasma on its own, melasma is stubborn, relapsing and sun-sensitive, and it needs a proper plan including rigorous sun protection.

It does not remove scars. Flat dark marks fade; indented or raised scars do not, and those need a dermatologist.

It does not replace sunscreen.

For formulators

Since this is a product decision we are asked about.

1. Use 5%. It matches the evidence, it is tolerable, and you can defend it.

2. pH matters. Niacinamide is most stable in a roughly neutral range. Poor pH control accelerates degradation to niacin, which causes flushing and reduces efficacy. Get this right.

3. Packaging and stability. Heat and light accelerate degradation. Opaque, well-sealed packaging, and real stability data, not an assumed shelf life.

4. Declare the percentage. In a category where most labels list ingredients with no quantities, a stated percentage is a genuine differentiator and the only way a customer can compare.

5. Resist the 10% and 20% temptation. It sells on the number and it generates returns from irritation, and in Indian skin it can worsen the pigmentation the customer bought it for.

6. And consider the pairing, niacinamide alongside a retinoid, or with azelaic acid, is a more useful product for this market than a higher-strength single active.

What is sayable: niacinamide’s role in supporting the skin barrier; help with the appearance of uneven tone and dark marks; support for oily skin; traditional use of manjistha and amla where included.

What is not: treats melasma, removes pigmentation, lightens skin, cures acne, or removes scars.

The short version

1. 5% is where the research sits, the supporting studies used roughly 2–5%.
2. Higher is not better. No trial body shows 10% or 20% outperforming 5%.
3. Irritation rises with concentration, and a lot of people cannot tolerate 10% on the face.
4. In darker skin, irritation drives pigmentation, so a product strong enough to irritate works against what you bought it for.
5. Flushing is often degraded niacinamide turning into niacin, a formulation and storage problem.
6. The best-established effect is barrier function; pigmentation works by reducing melanosome transfer rather than stopping pigment production.
7. The vitamin C incompatibility is largely a myth, combining them is generally fine; separate them if you prefer.
8. It pairs genuinely well with retinoids, reducing their irritation.
9. Give it 8–12 weeks for pigmentation, with photographs.
10. Sunscreen is not optional if you are treating marks.
11. It reduces excess pigmentation; it does not change your skin tone.
12. Any cream that works in days is suspect, steroid misuse on Indian faces is common and hard to reverse.

Product detail: Glowo 360 and pigmentation cream. Related: sunscreen, the one step that actually matters and पिगमेंटेशन कैसे हटाएँ.