Post-Inflammatory Hyperpigmentation (PIH): How to Treat It

Post-inflammatory hyperpigmentation (PIH) is a flat, discolored mark - ranging from light brown to dark brown or gray-black - that appears on the skin after an area of inflammation has healed. It is one of the most common skin concerns across all skin types and tones, yet it is frequently misunderstood, misidentified, and mistreated.

This blog is dedicated specifically to PIH. Not all hyperpigmentation types - if you want broader context on how PIH fits into the wider family of pigmentation concerns, our hyperpigmentation guide covers that ground. And not only blemish-related PIH, which is the narrow version of this conversation that most guides stop at. This is the full picture: PIH from acne, eczema flares, burns, waxing, insect bites, contact dermatitis, ingrown hairs, laser treatments, and beyond.

PIH affects every skin tone, but it is more pronounced and longer-lasting in medium to deeper skin tones - something this guide addresses directly and in depth.

By the time you finish reading, you will know what causes PIH at a biological level, how the science works, how long marks typically last, which ingredients are proven to fade them, how to build an effective daily routine, and how to prevent PIH from forming in the first place.

The best starting point for most people treating PIH is our Tranexamic Acid Serum ($19 / 30ml) - and we will explain exactly why as we go.

What Exactly Is Post-Inflammatory Hyperpigmentation?

Most people discover they have PIH the same way: the blemish clears, the eczema flare resolves, the insect bite stops itching - and yet a dark mark remains, sitting stubbornly on the skin long after the original incident has gone. That mark is PIH. Understanding what it actually is - at a biological level - is the first step to treating it effectively.

According to WebMD’s overview of post-inflammatory hyperpigmentation, PIH occurs when the skin produces extra melanin following irritation or injury. But the fuller scientific picture is worth understanding, because it is what makes certain treatment ingredients so precisely effective.

The Melanin Science, Explained Simply

Your skin contains two key cell types relevant to PIH. Keratinocytes are the surface skin cells that make up the outer layer of your skin. Melanocytes are the deeper pigment-producing cells that generate melanin - the pigment that gives your skin its color and helps protect it from UV radiation.

When skin experiences inflammation - from any cause - keratinocytes send out chemical distress signals. Those signals reach the melanocytes, which respond by ramping up melanin production. This is, in principle, a protective response. Melanin acts as a kind of natural shield against further damage. The problem is that in some people, and in response to some inflammatory triggers, this response goes into overdrive. Far more melanin is produced than the situation requires, it distributes unevenly across the affected area, and when the inflammation eventually resolves, a concentrated deposit of dark pigment is left behind.

That deposit is PIH.

PIH Is Not Scarring

This distinction matters enormously, both for how you feel about your skin and for how you treat it. PIH is not structural scarring. There is no damage to the collagen matrix beneath the skin’s surface. The skin’s architecture is entirely intact. PIH is purely a melanin distribution issue - which is genuinely good news, because melanin-related concerns respond well to targeted topical skincare in a way that true structural scarring does not.

If the marks on your skin are raised, indented, or have a textural quality, that is scarring - a different concern altogether. PIH is always flat. If you can feel a mark when you run a fingertip across it, you are not dealing with PIH alone.

PIH vs PIE: Knowing the Difference

A critical distinction worth understanding early is the difference between PIH and PIE - post-inflammatory erythema. Both are flat marks that remain after inflammation, and many people have both simultaneously, particularly after acne blemishes.

PIE is red or pink and is caused by damaged or dilated blood vessels beneath the skin’s surface. PIH is brown, dark brown, or gray-black and is caused by excess melanin. They look different, they have different causes, and they respond to different treatments.

There is a simple press test to tell them apart. Press a clean finger firmly onto the mark for a few seconds. If the color temporarily whitens or blanches under the pressure, that is PIE - the pressure is temporarily displacing blood from the dilated vessels. If the color stays exactly the same regardless of pressure, that is PIH - the pigment is sitting in the tissue itself and cannot be displaced.

For readers whose primary concern is post-blemish marks, our acne scars and post-blemish marks guide covers both PIH and PIE in that specific context. For understanding PIH as one type within the broader hyperpigmentation family, the full hyperpigmentation guide provides that wider context.

Now that you understand what PIH is and how it forms, the next question is: what set it off in the first place? The answer is broader than most people expect.

What Causes Post-Inflammatory Hyperpigmentation? (It Is Not Just Acne)

Here is the single most important thing to understand about PIH: any event that causes inflammation in the skin can trigger it. Acne and blemishes are the most commonly discussed cause - but they are far from the only one. If you have dark marks and you have never had a breakout in your life, this section is written for you.

The underlying mechanism is always the same: inflammation activates the keratinocyte-melanocyte signaling pathway, melanocytes overproduce melanin, and a dark mark is left behind. The cause of the inflammation changes. The biological response does not.

Acne and Breakouts

The most talked-about PIH trigger. When a blocked pore becomes inflamed - whether as a pustule, papule, or cyst - the surrounding tissue experiences significant inflammatory activity. After the blemish resolves, a dark mark often remains in its place. Picking or squeezing blemishes dramatically worsens this response by intensifying the inflammation and pushing it deeper into the tissue. Our acne scars and post-blemish marks guide covers this specific cause in full detail.

Eczema Flares

Eczema is a chronic inflammatory skin condition, and PIH is one of its most common long-term consequences - particularly in people with medium to deeper skin tones. During an eczema flare, the affected skin is in a state of prolonged inflammation. When that flare eventually resolves, the skin’s pigment-producing response can leave behind PIH that persists long after the eczema itself has quieted. For people with recurring eczema, new PIH is continuously being created alongside existing marks - which is why managing the underlying condition is as important as treating the resulting pigmentation.

Contact Dermatitis

Contact dermatitis is a localized inflammatory reaction triggered by exposure to an irritant or allergen. Common culprits include certain metals (nickel in jewelry, for instance), fragranced products, household chemicals, and plant contact. The affected area becomes inflamed, and once that inflammation resolves, PIH can appear precisely in the shape of whatever triggered the reaction - a patch of darker skin where a bracelet sat, or where a product was applied.

Burns, Including Sunburn

Thermal burns and UV burns both trigger a strong melanin response. Sunburn-induced PIH is particularly common and frequently underestimated - many people attribute lasting dark patches to the sun exposure itself rather than recognizing them as PIH following the inflammatory sunburn event. This is also one of the reasons daily SPF is non-negotiable when treating PIH: UV exposure both causes and significantly worsens it.

For a deeper understanding of why sun protection matters every single day, do I need to wear SPF all year round? sets out the case clearly.

Waxing and Hair Removal

Waxing involves heat, friction, and the mechanical trauma of stripping hair from the follicle. All three are inflammatory in nature. For people with medium to deeper skin tones in particular, the melanocyte response to this kind of localized trauma can be strong enough to produce PIH - particularly in areas that are waxed repeatedly, such as the upper lip, underarms, and legs.

Ingrown Hairs

An ingrown hair creates localized inflammation as the trapped hair irritates the surrounding skin. The same melanin overproduction pathway is triggered, and if the ingrown hair is picked or squeezed, the inflammation intensifies. Dark marks left by ingrown hairs - particularly on the legs and bikini area - are PIH.

Insect Bites and Stings

The body’s immune response to an insect bite produces localized inflammation that can be surprisingly significant. The resulting dark marks - especially on the legs, where bites are most common - can persist for months and are classic PIH.

Laser and Aesthetic Treatments

Laser therapies work by creating controlled injury to the skin. For many skin tones, this is manageable - but for people with darker skin tones, the melanocyte response to that controlled injury can result in PIH. This is a known and documented risk of certain laser treatments, and it underscores why discussing PIH prevention strategies with a qualified clinician before any procedure is important.

Psoriasis Flares

Like eczema, psoriasis is a chronic inflammatory skin condition. Flares leave PIH in resolved areas, and the cyclical nature of the condition means new PIH is regularly being created alongside existing marks.

Cuts, Abrasions, and Minor Skin Injuries

Any wound that heals through an inflammatory process can result in PIH. A scraped knee, a cat scratch, a surgical incision - if the healing process involves significant inflammation, a dark mark may follow.

Aggressive or Incompatible Skincare

This cause is frequently overlooked, and it is an important one. Over-exfoliation, the misuse of strong actives, or the use of products that cause irritation and inflammation can all trigger PIH - particularly in medium to deeper skin tones where the melanocyte response to irritation is stronger. Using too much glycolic acid, layering incompatible actives, or introducing retinol too aggressively can all produce the inflammation that leads to PIH. The solution is not to avoid active skincare, but to introduce it correctly.

A 2024 systematic review published in the Journal of the European Academy of Dermatology and Venereology by Kashetsky et al. noted that while most clinical research on PIH treatment has focused on acne-related causes, PIH occurs across a much broader range of inflammatory triggers - reinforcing exactly the breadth of causes outlined here.

PIH on the Body, Not Just the Face

One of the most underacknowledged facts about PIH is that it occurs anywhere on the body where inflammation has taken place. Legs are a common site - insect bites, shaving irritation, ingrown hairs, and eczema all frequently affect the legs and leave PIH behind. Arms and the décolletage are common eczema sites. The back and chest can carry PIH from acne breakouts. Any body area exposed to burns, friction, or trauma is susceptible.

The same principles and ingredients that treat facial PIH apply to body PIH - with the additional consideration that skin cell turnover is slower on the body than on the face, meaning improvement timelines are typically longer.

With the full picture of PIH causes established, the question every reader now has is the same: is this going to go away, and if so, how long is it going to take?

Does PIH Go Away? How Long Does It Last?

The honest answer, which you deserve upfront: for the vast majority of people, PIH is not permanent. It does fade. But “it fades eventually” is not nearly specific enough to be useful, so here is the more complete answer.

Realistic Timelines for PIH Fading

The timeline for PIH to fade depends on several factors - but unlike many answers in skincare that hide behind “it depends,” here are the actual numbers:

Mild, superficial PIH: Visible fading can begin within 4-8 weeks with a consistent routine that includes targeted treatment ingredients and daily SPF.
Moderate PIH: Significant fading typically takes 3-6 months of consistent treatment. You will see progressive improvement month on month.
Deep or long-standing PIH: Can take 6-12 months or longer. Deeper pigmentation - from prolonged or severe inflammation, or from PIH that has been present for a long time without treatment - requires patience and consistency.
PIH in medium to deeper skin tones: Takes longer at every stage because melanocytes are more densely active and produce a stronger, more sustained response. But it absolutely does fade with the right approach. The depth of the mark does not determine whether it will fade - only how long it will take.
PIH on the body: Body skin has a slower cell turnover rate than facial skin. Marks on the legs, arms, or back typically take longer to fade than equivalent facial PIH - sometimes significantly longer.

For a detailed look at how long the hero treatment ingredient specifically takes to show results, how long does Tranexamic Acid take to work? gives realistic, week-by-week expectations.

What Determines How Quickly PIH Fades?

Several factors influence the rate of improvement:

Depth of the original inflammation - A deep, cystic blemish or a severe eczema flare produces deeper PIH than a surface-level event. Deeper PIH fades more slowly.
How long the mark has been present - Fresh PIH responds faster than marks that have been sitting on the skin for months or years. Starting treatment early makes a meaningful difference.
Skin tone - Medium to deeper skin tones have more active melanocytes, which means marks are deeper at baseline and take longer to clear - but they do clear with consistency.
Whether the original trigger is still active - If you are still experiencing recurring acne breakouts, ongoing eczema flares, or repeated waxing without protective measures, new PIH is constantly being created alongside existing marks. Managing the underlying trigger is not optional if you want to see real progress.
Daily SPF use - This is not a minor consideration. UV exposure is the single biggest obstacle to PIH fading. Every day without SPF, UV stimulates melanocytes to produce more melanin, deepening existing marks and working directly against every treatment ingredient you are using.
Consistency of treatment - PIH responds to sustained, consistent treatment. A routine used intermittently will produce intermittent results.

What Makes PIH Worse or Prevents It From Fading

Beyond UV exposure without SPF, several behaviors actively worsen PIH or stall its fading:

Picking, scratching, or otherwise interfering with active blemishes, eczema patches, or bites - each interference re-triggers inflammation and deepens the PIH response
Using harsh, irritating, or incompatible actives that cause inflammation in the skin
Not treating the underlying inflammatory condition driving new PIH

PIH without any treatment will, in many cases, eventually fade on its own. Superficial PIH may resolve over many months. Deeper PIH may persist indefinitely without intervention. But proactive, targeted treatment dramatically shortens that timeline - and our Tranexamic Acid Serum is the most effective starting point we recommend.

The right approach is not passive. Knowing which ingredients to reach for - and why they work - is exactly what the next section covers.

The Best Ingredients for Treating Post-Inflammatory Hyperpigmentation

Different ingredients target PIH through different mechanisms. Some work upstream by blocking the melanin production signal. Others work at the surface by accelerating cell turnover so that pigmented cells shed faster. Some address the inflammatory driver directly. The most effective routines combine ingredients that work at multiple points in the PIH process.

Here is what the evidence supports, and which products to reach for.

Tranexamic Acid (2%) - The Hero Ingredient for PIH

Tranexamic Acid is, for most people treating PIH, the single most important ingredient to start with. Its mechanism is precise: it blocks the keratinocyte-melanocyte signaling pathway at the point where inflammation triggers excess melanin production. In other words, it works upstream of the problem - interrupting the signal that tells melanocytes to overproduce, rather than simply trying to manage the resulting pigment after the fact.

This upstream mechanism makes Tranexamic Acid particularly well-suited to PIH specifically - because PIH is, at its core, a consequence of exactly the signaling pathway that Tranexamic Acid disrupts.

What makes it additionally suitable for a wide range of users is its exceptional tolerability profile. It is non-irritating, non-photosensitizing, suitable for sensitive skin, and pregnancy-safe. Unlike some brightening ingredients that come with trade-offs - irritation risk, the need for careful sun protection, contraindications in pregnancy - Tranexamic Acid has virtually none.

Our Tranexamic Acid Serum ($19 / 30ml) contains 2% Tranexamic Acid alongside 2% Acai Berry Extract and a Vitamin C derivative for triple-action brightening. It is designed for use in both the AM and PM routines. For the full scientific background on this ingredient, our Tranexamic Acid ingredient guide goes deeper on the mechanism and the evidence.

Azelaic Acid (10%) - The PIH Specialist for Sensitive and Reactive Skin

Azelaic Acid approaches PIH from a different angle. Its primary mechanism in this context is anti-inflammatory - it calms the inflammatory cascade that creates PIH in the first place, addressing the root cause rather than just the resulting mark. It also mildly inhibits tyrosinase, the enzyme involved in melanin production, adding a direct brightening effect alongside its anti-inflammatory action.

This dual approach makes Azelaic Acid particularly valuable for PIH caused by eczema, rosacea, contact dermatitis, and other inflammatory skin conditions - where calming the inflammatory driver is as important as targeting the resulting pigmentation. It is especially well-suited to sensitive skin types where stronger brightening actives might cause irritation and - counterproductively - more PIH.

To the question many people search specifically: does azelaic acid help with post-inflammatory hyperpigmentation? Yes - and clinically meaningfully so. It is pregnancy-safe and suitable for use AM and PM.

Our 10% Azelaic Acid Serum for Redness Relief ($20 / 30ml) has been clinically proven to minimize redness in four days. For the full ingredient breakdown, the azelaic acid ingredient guide covers the evidence in detail.

Niacinamide (10%) - Calming the Inflammatory Driver

Niacinamide addresses PIH through two complementary mechanisms. First, it reduces the inflammatory response that triggers melanin overproduction in the first place - meaning it helps prevent new PIH from forming at the same time as it helps fade existing marks. Second, it inhibits the transfer of melanin from melanocytes to surrounding skin cells, reducing the spread of pigmentation across the affected area.

This makes Niacinamide particularly valuable for people whose PIH is ongoing - where recurring acne, eczema flares, or other triggers keep creating new marks. Niacinamide helps break that cycle while actively fading what is already there. It is safe for all skin types, pregnancy-safe, and especially well-suited to oily and acne-prone skin given its additional pore-minimizing and sebum-regulating properties.

Our 10% Niacinamide Serum ($13 / 30ml) is safe for AM and PM use and layers well with Tranexamic Acid. The niacinamide ingredient guide covers the full science.

Vitamin C (15% Ascorbyl Glucoside) - Brightening and Antioxidant Defense

Vitamin C serves two distinct functions in a PIH routine. First, it inhibits tyrosinase - the enzyme that catalyzes melanin production - directly reducing the amount of pigment being produced. Second, it neutralizes UV-triggered free radical damage, providing a layer of antioxidant defense that complements SPF by addressing the oxidative stress that UV exposure creates in the skin.

The form matters significantly here. Our 15% Vitamin C + EGF Serum ($20 / 30ml) uses Ascorbyl Glucoside - a stable, gentle derivative that does not oxidize in the bottle, does not cause the irritation associated with L-Ascorbic Acid, and is suitable for sensitive skin. It is best used in the AM, where its antioxidant properties work alongside your SPF to protect against UV-driven melanin stimulation throughout the day. It pairs powerfully with Tranexamic Acid.

The Vitamin C ingredient guide covers how different Vitamin C derivatives compare and what the evidence supports.

Glycolic Acid (10%) - Accelerating Cell Turnover

Glycolic Acid operates differently from the ingredients above. Rather than blocking melanin production, it accelerates the removal of already-pigmented cells from the skin’s surface. As an alpha hydroxy acid (AHA), it dissolves the bonds between dead surface skin cells, causing them to shed faster and revealing the fresher, less pigmented skin beneath.

Does glycolic acid help with post-inflammatory hyperpigmentation? Yes - meaningfully so, especially when combined with ingredients that work upstream on melanin production. The two mechanisms are complementary: blocking new melanin while removing existing pigmented cells at the surface.

The critical usage rules: PM only, 2-3 times per week (not nightly), and always follow with SPF the next morning because exfoliation increases photosensitivity. Do not use directly on actively inflamed skin. Our Glycolic Acid Toner($18 / 100ml) is the go-to format for facial use. On the body, the Glycolic Acid Exfoliating Body Stick targets both PIH and surface texture on areas like the legs and arms.

Retinol and Retinal - Long-Term Skin Renewal

Retinoids are the long-game ingredient for PIH - particularly for deeper, more established marks. They work by accelerating the entire skin cell renewal cycle, meaning pigmented cells at the surface are shed and replaced faster. They also inhibit tyrosinase, adding a direct melanin-suppression effect to their renewal action.

For long-standing PIH that has not responded as quickly as hoped to other approaches, adding a retinoid to the PM routine drives meaningful progressive improvement over time.

For those new to retinoids, our Starter Retinol ($15) is the correct entry point - using a lower concentration to allow the skin to adjust before building up. For those already experienced with retinoids, our Advanced Retinal delivers faster results. Both are PM-only products and should never be used on actively inflamed or irritated skin.

For comprehensive guidance on using retinoids for post-inflammatory marks, retinol for scarring and post-acne marksis the definitive resource. The retinol ingredient guide covers the wider science, and what not to mix with retinol is essential reading before introducing a retinoid into a routine that already contains exfoliating acids.

SPF - The Non-Negotiable Treatment Step

SPF is not optional in a PIH routine. It is not a nice-to-have finish. It is a treatment step - arguably the most important one.

UV exposure stimulates melanocytes to produce more melanin. For skin that already has active PIH, every unprotected sun exposure deepens existing marks and creates the conditions for new ones. UV exposure undoes the work of every other ingredient listed above. A routine built around Tranexamic Acid, Vitamin C, and glycolic acid will deliver a fraction of its potential if SPF is skipped.

Choose a broad-spectrum SPF 30 or higher suited to your skin type and wear it as the final AM step, every single day - regardless of the weather or the season. Visit our SPF guide to find the right formula for your skin. For the case for year-round SPF use, do I need to wear SPF all year round? makes it compellingly.

With the ingredients toolkit in place, the next step is knowing exactly how to put them together into a daily routine.

How to Build an Effective PIH Skincare Routine

Knowing which ingredients to use is the foundation. Knowing how to combine them - in the right order, at the right frequency, without creating the kind of irritation that makes PIH worse - is what turns a collection of good products into a genuinely effective routine.

Morning (AM) Routine for PIH

Step 1 - Cleanse: Begin with a gentle cleanser appropriate to your skin type. For oily or acne-prone skin, our Salicylic Acid Cleanser is effective without stripping. For sensitive or dry skin, the Oat Cleansing Balm ($17 / 150ml) is a calming, non-disruptive option that supports the skin barrier.

Step 2 - Hydrate: Apply the Hyaluronic Acid Serum to damp skin immediately after cleansing. This creates the hydrated base that allows subsequent serums to penetrate effectively and supports the skin barrier throughout the day.

Step 3 - Treat: Apply our Tranexamic Acid Serum as the core brightening step. Use it AM and PM for maximum effect - this is the foundation of your PIH treatment routine.

Step 4 - Brighten (optional boost): Layer the 15% Vitamin C + EGF Serum after the Tranexamic Acid for dual-action brightening and antioxidant UV defense. Wait approximately 60 seconds between layers to allow each serum to settle before applying the next.

Step 5 - Moisturize: For oily or combination skin, the Omega Water Cream is a lightweight, balancing option. For dry skin, the BioActive Ceramide Moisturizer delivers rich barrier support.

Step 6 - SPF: Apply a broad-spectrum SPF 30 or higher as the final AM step, every morning, without exception. Visit our SPF guide to choose the right formula for your skin type. Apply after moisturizer and before any makeup.

Evening (PM) Routine for PIH

Step 1 - Cleanse: If you have worn SPF or makeup during the day, double cleanse. Begin with the Oat Cleansing Balmto dissolve and remove SPF fully before following with your regular cleanser. Incomplete SPF removal can clog pores and contribute to breakouts - and more breakouts mean more PIH.

Step 2 - Hydrate: Apply the Hyaluronic Acid Serum to damp skin to support overnight hydration and barrier function.

Step 3 - Treat: Continue PIH treatment with the Tranexamic Acid Serum. Its non-irritating profile makes it safe and effective to use at both AM and PM.

Step 4 - Exfoliate (2-3 nights per week, not nightly): On exfoliation nights, apply the Glycolic Acid Toner after your Tranexamic Acid Serum to accelerate surface cell turnover. Do NOT use on the same nights as retinol.

Step 5 - Renew (alternate nights from exfoliation): On non-exfoliation nights, use either Starter Retinol (if you are new to retinoids) or Advanced Retinal (for experienced retinoid users). PM only. Never layer directly with glycolic acid in the same routine.

Step 6 - Moisturize: Finish with the BioActive Ceramide Moisturizer to support overnight barrier repair and lock in the treatment steps applied above.

The Beginner’s Starting Point

If this feels like a lot, here is the simplest effective entry point:

AM: Cleanser - Tranexamic Acid Serum - Moisturizer - SPF
PM: Cleanser - Tranexamic Acid Serum - Moisturizer

Start here. Use this consistently for 2-3 weeks. Then add one new product - Vitamin C in the AM, or glycolic acid 2 nights per week in the PM - and allow the skin to adjust before adding anything else. Building slowly prevents the irritation that creates more PIH.

PIH on the Body - Routine Adjustments

Body PIH follows the same ingredient principles, but the format needs to suit the application area. The Glycolic Acid Exfoliating Body Stick is designed specifically for body use, targeting both PIH and surface texture on the legs, arms, and back. Apply SPF to any body areas with PIH that are regularly exposed to UV - particularly the legs and arms.

Body skin has a slower cell turnover rate than facial skin, so improvement takes longer. Expect the timeline milestones above to shift outward by several weeks to a few months for body PIH.

The key layering rule: Glycolic Acid and retinol should never be used in the same PM routine. Alternate them across different evenings. Vitamin C stays in the AM routine. Tranexamic Acid is safe AM and PM. For a full reference on safe product layering, what not to mix with retinol and the skincare routine guide are the places to go.

Understanding your routine is powerful. Understanding how your skin tone affects every part of this picture - from how PIH forms to how fast it fades - takes that knowledge one essential step further.

PIH and Skin Tone: What People with Medium to Deeper Skin Tones Need to Know

Post-inflammatory hyperpigmentation is a concern across every skin tone - but it is not an equal-opportunity one. For people with medium to deeper skin tones (Fitzpatrick types III-VI), PIH tends to be deeper in color, more persistent, and more psychologically significant than in lighter skin tones. Understanding why helps you work with your skin’s biology rather than against it.

Why Skin Tone Affects PIH

People with medium to deeper skin tones have a higher density of melanocytes, and those melanocytes are more reactive to inflammatory signals. When any inflammatory event occurs - a blemish, an eczema flare, friction from waxing - the melanocyte response is stronger, producing more melanin than in lighter skin tones experiencing the same trigger. The result is deeper pigmentation that takes longer to clear.

This is not a flaw in darker skin. It is skin biology - a more responsive melanin system that, in everyday life, provides greater natural protection against UV damage. The trade-off is a heightened susceptibility to PIH following inflammation.

According to research specifically reviewing PIH in skin of color, PIH represents one of the most significant dermatological concerns for people with Fitzpatrick skin types IV-VI, with marks that are deeper, longer-lasting, and associated with greater impact on quality of life. This is a real and well-documented clinical reality - not an exaggeration.

Adapting Your Approach for Medium to Deeper Skin Tones

Several adjustments make a meaningful difference for people with medium to deeper skin tones:

Prioritize anti-inflammatory ingredients as much as brightening ones. Calming the inflammatory trigger at source - with Niacinamide and Azelaic Acid as daily pillars - reduces the melanin output before it becomes PIH. Treating the result without addressing the driver is a partial solution.
Avoid over-exfoliation and aggressive actives. Any additional irritation creates more inflammation, which produces more PIH. This is a cycle that traps many people: using harsher actives in the hope of faster results, causing irritation, and creating new PIH in the process. With medium to deeper skin tones, the margin for error with aggressive actives is narrower. Build slowly, use gently, and let the routine do its work over time.
Tranexamic Acid’s tolerability advantage is particularly relevant here. Its non-irritating, non-photosensitizing profile means it can be used consistently without the risk of setting off new inflammation - a meaningful consideration when irritation itself is the enemy.
Consistent SPF is proportionally more critical. UV deepens PIH more dramatically in skin with higher melanocyte density. Missing SPF days costs more in terms of PIH persistence for medium to deeper skin tones than for lighter ones. Our SPF guide covers how to choose and apply effectively.

Debunking a Harmful Myth: SPF for Darker Skin Tones

Darker skin tones are not immune to UV damage. This is a persistent and genuinely harmful myth that contributes to real harm - including worsened PIH, accelerated photoaging, and increased skin cancer risk. Melanin provides some degree of natural UV protection, but not complete protection. SPF is equally non-negotiable across all skin tones when treating or preventing PIH.

PIH During Pregnancy

Hormonal changes during pregnancy increase the skin’s overall sensitivity to inflammatory triggers, which can make PIH more pronounced or harder to fade during this period. The good news is that the most important PIH treatment ingredients are pregnancy-safe: Tranexamic Acid, Vitamin C (as Ascorbyl Glucoside), Niacinamide, and Azelaic Acid can all be used throughout pregnancy.

The ingredient to avoid during pregnancy is retinol - retinoids in any form should not be used while pregnant. For a comprehensive guide to which ingredients are safe and which to avoid, our pregnancy-safe skincare guide covers everything you need to know.

Preventing PIH Before It Forms

The most effective PIH intervention is prevention. For people with medium to deeper skin tones especially - where the melanocyte response is stronger - preventing the inflammatory trigger from creating PIH in the first place is far easier than fading marks after they have formed.

Practical prevention steps:

Treat underlying inflammatory conditions - eczema, recurring acne, rosacea - consistently and proactively, rather than managing flares reactively
Do not pick, scratch, or interfere with active blemishes, eczema patches, insect bites, or any other inflamed skin. Each interference deepens and prolongs the inflammation
Apply SPF daily to any skin exposed to UV
Introduce skincare actives one at a time and allow the skin to adjust before adding more - actives that cause irritation create the inflammation that leads to PIH
Before any laser treatment or aesthetic procedure, discuss PIH risk management with the treating clinician - particularly if you have a medium to deeper skin tone

If you are unsure what type of hyperpigmentation you are dealing with, what type of hyperpigmentation do I have?helps you identify your specific concern before building a routine around it.

When to See a Dermatologist

If 3-6 months of consistent treatment - with targeted ingredients and daily SPF - produces no visible improvement in your PIH, it is worth seeking professional assessment. A dermatologist can determine whether prescription-strength treatments or in-clinic procedures are appropriate, and can assess whether any underlying skin condition is contributing to ongoing PIH that topical skincare alone cannot fully address.

Frequently Asked Questions About Post-Inflammatory Hyperpigmentation

What is post-inflammatory hyperpigmentation?

Post-inflammatory hyperpigmentation (PIH) is a flat, dark or discolored mark left on the skin after an area of inflammation has healed. It is caused by excess melanin production triggered by the skin’s inflammatory response. PIH affects all skin types and tones, though it is more pronounced and longer-lasting in medium to deeper skin tones. It is not scarring - the skin’s structure is intact, and it responds well to targeted topical treatment.

What causes post-inflammatory hyperpigmentation?

Any form of skin inflammation can trigger PIH - including acne breakouts, eczema flares, burns, contact dermatitis, waxing, ingrown hairs, insect bites, psoriasis, cuts, abrasions, and skin irritation caused by incompatible skincare. The mechanism is the same regardless of the cause: inflammation signals melanocytes to overproduce melanin, and the excess pigment remains after the inflammation resolves.

Does post-inflammatory hyperpigmentation go away?

Yes - for the majority of people, PIH does fade with time and the right treatment. The timeline depends on the depth of the original inflammation, the skin tone of the person affected, and whether daily SPF is being used consistently. Without treatment, superficial PIH may fade over many months to years. With targeted ingredients and daily SPF, fading is significantly accelerated.

How long does post-inflammatory hyperpigmentation last?

Mild PIH can begin to visibly fade within 4-8 weeks of consistent treatment. Moderate cases typically take 3-6 months. Deeper or longer-standing PIH - particularly in medium to deeper skin tones - can take 6-12 months. Body PIH takes longer than facial PIH due to slower skin cell turnover. For ingredient-specific timeline expectations, how long does Tranexamic Acid take to work? gives week-by-week guidance.

Is post-inflammatory hyperpigmentation permanent?

For most people, PIH is not permanent with the right approach. Very deep, long-standing PIH that has not been treated and has received continued UV exposure without protection is the hardest to shift - but even in these cases, targeted treatment produces improvement. If 3-6 months of consistent treatment yields no visible change, a dermatologist can assess whether prescription-level options are warranted.

How do I get rid of post-inflammatory hyperpigmentation?

The most effective approach combines ingredients that work at different points in the PIH process. Start with our Tranexamic Acid Serum AM and PM to block the melanin signaling pathway. Add Vitamin C in the AM for brightening and UV defense. Use Niacinamide to calm ongoing inflammation. Incorporate Glycolic Acid 2-3 nights per week to accelerate cell turnover. Use daily broad-spectrum SPF without exception to prevent UV from deepening marks. Consistency across all five pillars is what produces results.

Does glycolic acid help with post-inflammatory hyperpigmentation?

Yes. Glycolic acid accelerates skin cell turnover, shedding pigmented surface cells faster and revealing more evenly toned skin beneath. It does not block melanin production at source, but it speeds up the removal of already-pigmented cells - making it a complementary, not standalone, PIH treatment. Use the Glycolic Acid Toner in the PM, 2-3 times per week, and always use SPF the following morning. Do not apply directly to actively inflamed or broken skin.

Does azelaic acid help with post-inflammatory hyperpigmentation?

Yes, particularly via its anti-inflammatory mechanism. Azelaic acid calms the inflammatory response that drives excess melanin production - targeting PIH at its trigger rather than the resulting mark. It is especially effective for PIH caused by eczema, rosacea, or contact dermatitis, and for sensitive skin types where stronger actives might cause irritation and worsen things. Our 10% Azelaic Acid Serum for Redness Relief is pregnancy-safe and suitable for both AM and PM use.

What is the difference between PIH and PIE?

PIH (post-inflammatory hyperpigmentation) is brown or dark flat marks caused by excess melanin. PIE (post-inflammatory erythema) is red or pink flat marks caused by damaged or dilated blood vessels. To distinguish them: press a finger firmly onto the mark. If it temporarily whitens, it is PIE. If the color stays unchanged, it is PIH. Many people have both simultaneously - particularly after acne breakouts. They require different treatment approaches, though some ingredients, including Niacinamide and Tranexamic Acid, support improvement of both. The acne scars guide covers PIH and PIE in the context of post-blemish marks.

Can PIH appear on the body, not just the face?

Yes. PIH can occur anywhere on the body where inflammation has taken place - legs from insect bites, shaving irritation, or ingrown hairs; arms and the décolletage from eczema; the back and chest from acne breakouts; any area exposed to burns or trauma. The same ingredients treat body PIH as facial PIH. The Glycolic Acid Exfoliating Body Stick is particularly effective for body areas. Improvement timelines are typically longer on the body than the face due to slower skin cell turnover.

Where to Go From Here

PIH - regardless of what caused it, where it sits on the skin, or how long it has been there - is addressable. The science is clear, the ingredients are proven, and the approach is consistent: target the melanin pathway upstream with Tranexamic Acid, support it with anti-inflammatory actives like Niacinamide and Azelaic Acid, accelerate cell turnover with glycolic acid or a retinoid, and protect every day with broad-spectrum SPF.

Everyone’s skin is different. Causes, timelines, and skin tone all affect how quickly you see results. But the principles are the same across the board - and knowledge of those principles is what allows you to build a routine that actually works, rather than layering products and hoping for the best.

Clear skin is achievable. Consistency and the right ingredients do the rest.

Start with our Tranexamic Acid Serum ($19) - the most effective, well-tolerated starting point for treating PIH, suitable for all skin types, morning and evening.

Not sure where your skin sits within all of this? Take our Skincare Quiz for a personalized routine built around your specific concerns. Or chat to the askINKEY team for tailored advice from someone who will take the time to understand your skin properly.

For the broader context on hyperpigmentation types and how PIH relates to the wider picture, explore our hyperpigmentation guides.