Six vitamin C serums. Three rounds of AHA peels. Months of tretinoin purge. And somehow the dark spots are still there, sometimes darker than when you started.
That's not bad luck. It's a pattern. Aggressive actives inflame the skin. Inflammation triggers melanin production. New PIH forms before the old PIH fades. You're running in place.
Building a PIH routine that works means solving the sequence first, then the ingredients.
The Rule That Governs Everything: Inflammation Is the Enemy
Post-inflammatory hyperpigmentation forms when inflammation signals melanocytes to overproduce pigment. The mark isn't the original injury. It's the skin's overreaction to it.
Which means any routine step that re-inflames, over-exfoliation, acid overload, barrier disruption, produces new PIH even as it claims to treat the old. As one person put it: "Many of my worst episodes were self-inflicted... ultimately cause the irritation I was trying to avoid."
That's the trap. The exit is calibration, not escalation.
AM Routine: Protection First, Brightening Second
Step 1: Gentle Cleanser
Morning cleanse strips nothing. Lukewarm water or a low-pH gel cleanser that doesn't foam aggressively. Your barrier is the wall that stops inflammation from getting in. Don't dissolve it before 9 a.m.
Step 2: Brightening Serum (Optional, Read the Calendar First)
Niacinamide or tranexamic acid (TXA) are the two actives that brighten without provoking. Both inhibit melanin transfer to the skin's surface. Neither exfoliates. Neither causes purging. If your skin is reactive, skip this step entirely for the first two weeks. Introduce it once your barrier is stable.
Vitamin C is fine here if yours is stable and genuinely formulated. The problem: most ascorbic acid serums oxidize within 30 to 60 days of opening, rendering them ineffective before the bottle is half done. Check the color. If it has turned orange or brown, it is already inert.
Step 3: Moisturizer with Barrier Actives
Ceramides, niacinamide, peptides. Something that seals. Skin that's dehydrated inflames faster and heals slower. This step isn't cosmetic. Polynae PDRN Collagen Capsule Cream fits here: PDRN (polynucleotide extracted from salmon DNA) works by activating the cells that build collagen, supporting dermal repair from underneath while the surface brightens. For PIH that's been cycling for months, this layer addresses what most brightening serums can't reach.
Step 4: SPF 50, Non-Negotiable
UV exposure is the single fastest way to deepen PIH. Melanin that's already overactive becomes more so under UV. Skip SPF on two consecutive mornings and you can undo three weeks of brightening progress.
SPF compliance is entirely a texture problem. If your sunscreen pills, feels greasy, or leaves cast on your skin, you'll find reasons not to wear it. The formulation matters more than the number on the bottle.
PM Routine: Repair at Night, Exfoliate Less Than You Think
Step 1: Double Cleanse (or Just Oil Cleanse)
Remove SPF fully. Residual sunscreen mixed with a PM retinoid or acid causes unnecessary occlusion and sometimes comedones. A clean canvas is part of the repair mechanism, not a bonus.
Step 2: Actives, One Per Night, Spaced Across the Week
This is where most PIH routines collapse. The temptation is to layer: retinoid on top of glycolic on top of kojic acid. The result is a wrecked barrier and fresh inflammation within two weeks.
The rule: one active per night, rotating across four nights maximum. The other three nights are repair nights, nothing stronger than your moisturizer.
- Night 1 and 2: Low-concentration AHA (glycolic or lactic, 5 to 8%). Exfoliates surface cells where older PIH sits. At this percentage, meaningful exfoliation without ablation.
- Night 3: Retinoid, if tolerated. Start low, 0.025% prescription or a low-percentage retinol. Accelerates cell turnover and supports collagen synthesis. Not for recently inflamed or barrier-damaged skin. Earn this step, don't start with it.
- Night 4: Kojic acid or TXA-based treatment. Inhibits the enzyme responsible for melanin production. Layering with exfoliants the same night negates the benefit and risks irritation.
Step 3: Repair Moisturizer, Every Night, Including Active Nights
Polynae PDRN Collagen Capsule Cream again. PDRN has over two decades of clinical use in wound healing and post-procedure skin recovery. The mechanism is collagen-cell activation at the dermal level, not surface occlusion. On active nights, it cushions the exfoliant's effect. On repair nights, it does the structural work. This is not a luxury step. It's the reason the actives above don't spiral into another inflammation cycle.
How to Know You're Over-Exfoliating Before the Damage Shows
The warning signs arrive before the visible reaction: skin that feels tight after cleansing, a subtle sting when your moisturizer goes on, slight redness that wasn't there last week. These are early signals. Pull back to repair nights only for five to seven days. Let the barrier recover before reintroducing any acid.
If you've already broken the barrier, raw, reactive skin that burns on contact with even water-based products, the PIH routine pauses entirely. Barrier repair is the first protocol. PIH brightening resumes only on stable skin.
The Honest Timeline
Shallow, surface-level PIH from a single breakout: four to six weeks on a compliant routine. Deeper PIH from repeated inflammation cycles, or UV-compounded pigmentation from years of skipped SPF: three to six months, with some marks taking longer depending on original depth.
The skincare industry cycles products every 60 to 90 days. That window is exactly too short to see real PIH results, which is why most people abandon routines that would have worked if held longer. The collagen-repair layer is the part that takes time. It's also the part that lasts.
Results you can see. Skin that holds them.
