Compare · Ingredients

Niacinamide vs Polyhydroxy Acids

Niacinamide: Supports barrier function, uneven tone and oiliness. Polyhydroxy Acids: Offers exfoliation through ingredients such as gluconolactone and lactobionic acid.

Research updated 2026-10-25

Six niacinamide products on white, including The Ordinary 10% + Zinc 1%, Paula's Choice Booster and EltaMD UV Clear

Five PHA toner and serum bottles lined up on white with clear liquid swatches beside them

Which one?At a glance What it helps Diagrams Using both Strengths Results Safety How it works Products Questions

Which one is right for you?

Choose Niacinamide if…

Choose for barrier support, uneven tone and oiliness; often the gentler starting point.

Barrier support or sensitive skin
Uneven tone or oiliness
You want a gentle, stable starting point

Choose Polyhydroxy Acids if…

Choose for mild exfoliation when stronger acids are uncomfortable; tolerance still varies.

Sensitive skin that stings with AHAs
Mild dullness or texture
Gentle exfoliation

Fine together

Can you use both?

A gentle pairing: PHAs exfoliate lightly and niacinamide calms.

At a glance

● Niacinamide

● Polyhydroxy Acids

Type

Vitamin B3 (nicotinamide)

Polyhydroxy acid (PHA) family

What it does

Supports the barrier and improves uneven tone

Offers exfoliation through ingredients such as gluconolactone and lactobionic acid.

Best for

Barrier support; uneven tone; oiliness

Acne; Dull Skin; Sensitive Skin

Studied concentrations

2–5%

14% gluconolactone in an acne trial; newer studies test mixed-acid formulas.

When to use

Morning or night

Start on a few evenings weekly; increase only if comfortable.

Time to results

About 4–12 weeks, depending on the concern

Often 8–12 weeks in small cosmetic studies; results may be subtle

Irritation

Usually low; stinging or redness can occur

Can still sting or cause a rash; sensitive skin does not guarantee tolerance.

Sensitive skin

Often suitable in a gentle formula

Choose a simple formula and test a small area first. Avoid actively inflamed or broken skin unless the product is specifically directed for it.

Available

Over the counter

Cosmetic or OTC products; some high-strength procedures are separate treatments.

What it helps

Compare uses by strength of evidence. Evidence level describes confidence in a benefit, not its size.

Evidence level

Niacinamide

Polyhydroxy Acids

Moderate evidenceSome supportive research

a very close view of irritated dry skin with fine flaking and no identifiable body part on light skin.

Barrier Support

Supports barrier lipids and helps reduce water loss in dry skin.

A relaxed forehead with faint shallow horizontal fine lines.

Wrinkles and Fine Lines

A small controlled trial of 5% niacinamide found modest improvement in fine lines.

Uneven Skin Tone.

Uneven Skin Tone

Can improve uneven pigmentation with regular use and sun protection.

Oiliness.

Oiliness

2% niacinamide improved some measures of facial oiliness in controlled studies.

—

Limited evidenceEarly or small studies

Inflamed acne on light skin. The spots sit in a patch of pink, and the ring of redness around each one is easy to see. A few have a yellow-white head, and the skin between them is dry and flaking.

Acne

Small trials suggest benefit for inflammatory acne; consider it a supporting option.

Flat tan patches with soft irregular edges across the forehead and upper cheek of an adult with light skin, the surface completely smooth.

Melasma

A small trial of 4% niacinamide found improvement alongside sunscreen.

Redness and fine superficial vessels across a light-skinned cheek and nose.

Rosacea

A niacinamide moisturizer was studied for barrier support; its other ingredients also matter.

Inflamed acne on light skin. The spots sit in a patch of pink, and the ring of redness around each one is easy to see. A few have a yellow-white head, and the skin between them is dry and flaking.

Acne

One controlled trial found fewer lesions with 14% gluconolactone.

Dull Skin on light skin.

Dull Skin

Small studies of PHA formulas suggest smoother surface texture.

Sensitive Skin on light skin.

Sensitive Skin

Some tested formulas were well tolerated; this is not proof that all PHAs suit reactive skin.

Insufficient evidence

Enlarged Pores on light skin.

Enlarged Pores

Less oil may make pores less noticeable; lasting pore-size reduction is unproven.

Extreme close-up of light skin in an active eczema flare, too close to tell which part of the body it is. Blotchy pink-red inflammation covers the whole frame with no clear edge, with small raised bumps, fine dry scale and a few fresh scratch marks.

Eczema

Barrier benefits do not establish niacinamide as an eczema treatment.

A relaxed forehead with pronounced deep horizontal furrows.

Deep Wrinkles

Fine-line improvement does not establish correction of deep folds.

Flat tan patches with soft irregular edges across the forehead and upper cheek of an adult with light skin, the surface completely smooth.

Melasma

The reviewed sources do not establish this ingredient as a treatment for this concern.

The front of one shin on pale skin. The surface is pink with fine white flaking and a few shallow cracks, and the skin around it is even in tone.

Dry Skin

The reviewed sources do not establish this ingredient as a treatment for this concern.

Acne scarring on light skin. Small sharply cut pits and broad shallow dips across a cheek, several sitting inside faint flat pink marks, with no active spots.

Acne Scarring

The reviewed sources do not establish this ingredient as a treatment for this concern.

How it works

Niacinamide mechanism diagram. Supports the skin barrier: Helps skin make lipids that reduce water loss. Reduces pigment transfer: Less pigment reaches neighboring skin cells. — Open full-size diagram
Diagram explanation and sources
Supports the skin barrier: Helps skin make lipids that reduce water loss. Reduces pigment transfer: Less pigment reaches neighboring skin cells.
Schematic illustration; not a measurement of skin penetration. Effects vary with ingredient identity and formulation.
Source 1 · Source 2 · Source 3 · Source 4

Polyhydroxy Acids mechanism diagram. Loosens surface cells: PHAs promote shedding in the outer skin. Helps bind water: Hydroxyl groups contribute to water binding. — Open full-size diagram
Diagram explanation and sources
Loosens surface cells: PHAs promote shedding in the outer skin. Helps bind water: Hydroxyl groups contribute to water binding.
Schematic illustration; not a measurement of skin penetration. Effects vary with ingredient identity and formulation.
Source 1 · Source 2 · Source 3

Using both in one routine

Built from where each one usually sits in a routine. Introduce one at a time.

Morning

Step 1

Cleanser

Step 2

Polyhydroxy AcidsMorning or night

Step 3

NiacinamideMorning or night

Step 4

Moisturizer

Step 5

Sunscreen

Night

Step 1

Cleanser

Step 2

Polyhydroxy AcidsMorning or night

Step 3

NiacinamideMorning or night

Step 4

Moisturizer

Strengths and forms

Concentrations

Clinical studies commonly use 2–5% niacinamide for particular concerns. Higher marketed strengths are not a proven upgrade for everyone.

2%

4–5%

10%

Studied for facial oiliness

Controlled studies tested a finished formula for measures of facial oiliness; results do not mean every oily skin needs niacinamide.

Studied for tone and skin aging

Different trials studied pigmentation, melasma or fine lines. The concern and finished formula matter.

Higher marketed concentration

Available in skincare, but not established as universally more effective than the lower studied strengths.

Choosing a strength: A comfortable 2–5% product is a reasonable place to look when choosing for the studied concerns; evaluate the complete formula.

Higher strengths: Higher percentages may sting or irritate some skin. Do not keep increasing the concentration when the product causes discomfort.

Formula matters: Niacinamide is also included in moisturizers without a stated percentage. That does not mean the moisturizer cannot support skin comfort.

PHA is a family name, not one ingredient or one standard strength. A clinical acne trial used 14% gluconolactone; that result cannot be transferred directly to lactobionic acid or mixed-PHA products.

14%

Studied gluconolactone lotion

An older controlled acne trial tested this specific formula. It does not establish the best percentage for all PHA skincare.

Choosing a strength: Check which PHA is listed, whether the product stays on or washes off, and whether it also contains other exfoliating acids.

Higher strengths: A PHA product can still irritate, particularly when combined with other acids. A high total-acid percentage is not a validated benefit rating.

Formula matters: The individual acid, acidity and base formula matter. A blended-acid percentage does not reveal the amount of each PHA.

Forms

Serum · Moisturizer · Toner

Toner · Serum · Cleanser

When you’ll see results

Approximate windows, not promises.

● Niacinamide

● Polyhydroxy Acids

First few weeks

First few weeksAssess comfort. Moisturizer benefits may appear before changes in tone or lines.

First few weeksAssess tolerance and texture; immediate softness can come from the base formula.

4–8 weeks

4–8 weeksOiliness or uneven pigmentation may begin to improve.

4–8 weeksSubtle changes may appear in some tested products; evidence varies.

8–12 weeks

8–12 weeksReassess tone and fine lines; expect modest changes.

8–12 weeksCompare photographs in the same lighting and reassess benefit.

3–6 months

3–6 monthsContinue if it helps and remains comfortable.

3–6 monthsPhotoaging trials often need several months; expect modest rather than dramatic change.

6–12 months

6–12 monthsLong-term benefit is less well defined than short-term results.

6–12 monthsLong-term evidence is limited for many cosmetic actives; continue only if useful.

Safety and sensitive skin

Common reactions

Stinging, redness, dryness or a rash can occur. Fragrance, preservatives and other ingredients may also contribute to a reaction.

Can still sting or cause a rash; sensitive skin does not guarantee tolerance.

When to stop

Stop for persistent burning, swelling or an itchy rash. Seek urgent help for trouble breathing or rapidly worsening facial swelling.

Stop for persistent burning, swelling, blistering or a new rash. Seek urgent care for breathing difficulty or a severe allergic reaction.

Sensitive or inflamed skin

Choose a gentle formula and test a small area. Barrier-support claims do not mean every product suits rosacea or eczema.

Choose a simple formula and test a small area first. Avoid actively inflamed or broken skin unless the product is specifically directed for it.

Pregnancy & breastfeeding

This topical ingredient is not a retinoid. Review the complete product with your clinician; do not assume every combination formula is suitable.

Not covered in this guide yet

Important limits

Niacinamide supports skincare; it does not replace diagnosis or established treatment of persistent acne, melasma or an inflamed rash.

Do not use a cosmetic product as a substitute for diagnosis of an unexplained, changing or persistent skin problem.

Pregnancy

Not covered in this guide yet

Low-strength leave-on acids are generally considered acceptable; ask the clinician managing your pregnancy.

How it works

In the skin

On the skin. A water-soluble vitamin used in serums and moisturizers.

Entering skin. Human studies show delivery into the outer skin; uptake depends on the formula.

Conversion. Cells use niacinamide to help make NAD+, which supports energy and repair.

Skin response. Supports production of barrier lipids, including ceramides, and helps reduce water loss.

Additional effects. Reduces pigment transfer between skin cells in laboratory models.

On the skin. The finished product delivers polyhydroxy acids in a particular vehicle.

Entering skin. No single molecular mass. The 500 Da guideline cannot be applied to this whole ingredient family or mixture.

Conversion. No activation step is established as necessary for its intended topical role.

Skin response. PHA ingredients promote surface exfoliation and may also bind water; individual acids and formulas differ.

Additional effects. Proposed pathways do not establish a measured depth of delivery or clinical benefit beyond the studies cited.

Getting in

Below the 500 Da guideline. Human studies show that the formula strongly affects uptake.

No single molecular mass. The 500 Da guideline cannot be applied to this whole ingredient family or mixture.

Product examples

Niacinamide

The Ordinary Niacinamide 10% + Zinc 1% — Budget serum.
Paula’s Choice 10% Niacinamide Booster — Mixes into moisturizer.
CeraVe PM Facial Moisturizing Lotion — Niacinamide plus ceramides.

Polyhydroxy Acids

Isntree Hyper Acid 4 AHA BHA PHA LHA 30 Serum
NeoStrata Ultra Moisturizing Face Cream
Gold Bond Ultimate Pedi Smooth Foot Cream

Common questions

Niacinamide:Does niacinamide help fine lines?

There is clinical evidence, including a small 12-week controlled trial of a 5% moisturizer. Expect modest improvement; it does not erase deep wrinkles.

Niacinamide:Is 10% better than 5%?

Not necessarily. Many clinical studies used 2–5%, and a higher concentration is not proven to work better for every concern.

Niacinamide:Can niacinamide treat acne by itself?

Small trials suggest benefit, but the evidence is limited. Persistent, painful or scarring acne needs an established acne treatment plan.

Niacinamide:Does niacinamide permanently shrink pores?

That has not been established. Less oil or a smoother appearance can make pores look less obvious without permanently changing their structure.

Niacinamide:Why does my niacinamide product sting?

The concentration, other ingredients or your skin barrier may be responsible. Reduce use or stop if irritation persists; you do not need to push through it.

Polyhydroxy Acids:What should I choose polyhydroxy acids for?

Choose for mild exfoliation when stronger acids are uncomfortable; tolerance still varies.

Polyhydroxy Acids:How strong is the evidence?

A 150-person trial tested 14% gluconolactone for acne. Evidence from that molecule or a mixed-acid serum does not establish identical effects for all PHAs.

Sources

Sources and further reading

Dermapedia on YouTube