Cosmetic dermatology: how common laser types work and typical recovery windows

Some topics only click after I hear a real person walk through them without sales-y sparkle. Lasers in cosmetic dermatology used to feel like that for me—too many colors, acronyms, and dramatic before–after photos to be sure what was real. Then I started keeping notes after my own consults and conversations with dermatology pros, and a calmer picture emerged: each laser family has a clear target in the skin, a sensible way it delivers heat or light, and a recovery window that follows from the physics. No magic, just mechanisms plus good aftercare. That’s what I want to share here—what happens under the hood, how long it usually takes to look presentable again, and small habits that make the post-procedure days kinder.

The moment lasers stopped feeling mysterious to me

It was a sketch on a notepad: three skin “targets” (water, hemoglobin, and melanin) and a few wavelength labels. Once I saw which wavelengths prefer which target, I could map the usual clinic names—PDL, Nd:YAG, CO2, Er:YAG, diode, thulium, “fractional”—to what they are doing. A high-value takeaway I wrote in the margin: downtime usually scales with how much of the epidermis you disrupt and how much heat you deliberately leave behind. Ablative resurfacing removes columns or sheets of tissue, so it needs more healing days. Non-ablative devices heat targets while leaving the surface intact, so redness and swelling tend to fade faster. If you want a quick primer to double-check basics, these helped me:

How the main laser families work in plain English

I find it easier to think in “families.” The device brand matters, but the family tells you the target and likely recovery. Here’s the cheat sheet I wish I had first:

  • Pulsed dye laser (PDL, ~585–595 nm) targets hemoglobin. It’s a go-to for facial redness, rosacea vessels, port-wine stains, and some scars. Classic settings can cause temporary purpura (purple bruising) where blood vessels clot; non-purpuric passes trade bruising for more sessions.
  • KTP (~532 nm) also leans toward hemoglobin and can address superficial vessels and some sun spots. Because 532 nm interacts with melanin, parameters matter more in darker skin tones.
  • Diode and Alexandrite (≈755–810 nm) primarily hit melanin, so they’re common for hair removal and certain pigmented lesions. The 810 nm diode is a workhorse; 755 nm alexandrite is effective in lighter skin types. Darker skin often does better with longer wavelengths like 1064 nm (see next bullet) plus careful settings.
  • Nd:YAG (1064 nm) penetrates deeper and is relatively “melanin-sparing,” making it a frequent choice for darker skin tones (Fitzpatrick IV–VI) in hair removal and deeper vessels like leg veins. It’s also used in some non-ablative rejuvenation protocols.
  • Fractional non-ablative (≈1440–1550 nm erbium glass, 1927 nm thulium) heat water in the dermis to stimulate collagen and address texture, pores, and dyschromia. They leave the surface intact while creating microscopic zones of injury underneath; your skin repairs these over days to weeks.
  • Ablative & fractional ablative (CO2 10,600 nm, Er:YAG 2940 nm) vaporize columns or sheets of tissue, directly resurfacing etched lines, acne scars, and severe sun damage. Er:YAG is often a touch “gentler” with less thermal spread; CO2 tends to create more tightening but also longer redness.
  • Q-switched and picosecond lasers (multiple wavelengths) deliver ultra-short pulses to shatter pigment or tattoo ink via photoacoustic effects with minimal heat. They’re precise and usually have low downtime but can form tiny crusts where pigment lifts.
  • IPL (not a laser) is a broad-spectrum light filtered for targets like sun spots and redness. It can be effective with trained hands, but its non-coherent light means more parameter finesse and eye protection are critical.

Two cross-cutting ideas changed how I set expectations: fractional vs. non-fractional (columns of micro-treatment vs. full-field) and pulse duration/fluence (how much and how fast energy is delivered). Fractional methods usually mean faster social downtime because healthy bridges of skin remain to speed healing. Longer pulses and lower fluences can be friendlier to melanin-rich skin when the target is blood or water rather than the pigment itself.

Typical recovery windows you can actually plan around

Every face is unique, and settings vary, but these are the ranges I keep on my calendar. I plan conservative first, knowing an extra day or two of healing sometimes happens, especially after stronger passes:

  • PDL for redness: immediate swelling and warmth; if purpura is induced, expect purple “polka dots” that fade in ~3–7 days. Non-purpuric settings may give 24–72 hours of redness and puffiness with little bruising. Makeup is often okay once skin is intact (ask your clinician).
  • Fractional non-ablative (1440–1550): pinkness and a “sunburn” feel for 24–72 hours. A dry, sandpapery texture and light flaking can last 3–7 days. Bronzing “grids” may be visible briefly under close light.
  • 1927 thulium for dyschromia: similar to above but with more noticeable bronzing; 3–5 days before you look fully presentable, though subtle flake can persist a week.
  • Fractional ablative CO2 or Er:YAG: ooze and crusting for 2–4 days, then fresh pink skin as re-epithelialization completes by about day 5–7. Background redness can linger 2–6+ weeks, fading with gentle care and sunscreen.
  • Fully ablative (full-field) resurfacing: social downtime is more like 7–14 days for initial healing, with redness softening over several weeks. The payoff can be substantial for etched lines and scars, but it’s a commitment.
  • Q-switched/picosecond for pigment: immediate whitening (“frosting”) then tiny crusts that shed in ~3–7 days. Tattoos may blister; dressings and ointment are your friends for the first few days.
  • Hair removal (diode/alex/Nd:YAG): pinkness and perifollicular bumps typically settle within hours to 1–2 days. Avoid tight gym wear on treated areas day-of.
  • IPL photofacial: redness 24–48 hours. Brown spots often darken before they flake over 3–7 days—that’s expected “peppering,” not a complication.

How many sessions? A rough, non-absolute mental model I use: hair removal often needs 6–8 spaced visits; PDL for facial vessels 2–4; non-ablative fractional 3–5; ablative fractional 1–2 deep sessions or several lighter ones. Your plan should be personalized to your skin type, goals, and ability to take downtime.

Matching goals to devices without hype

Instead of chasing brand names, I try to map goals to mechanisms. Here’s how I walk myself through it:

  • Diffuse redness or visible capillaries → PDL or KTP (longer pulses if you bruise easily or prefer minimal purpura). Consider Nd:YAG for deeper leg veins.
  • Sun spots and mottled pigment → 1927 thulium or IPL; for discrete spots, a Q-switched or picosecond pass can be precise.
  • Texture, pores, mild acne scarring → non-ablative fractional (1440–1550). Larger, tethered scars may benefit from fractional ablative or combined approaches.
  • Etched lines, severe photodamage, stubborn scars → fractional ablative CO2/Er:YAG with realistic downtime planning.
  • Unwanted hair → diode/alexandrite in lighter skin; long-pulse Nd:YAG in darker skin types with cautious settings and test spots.

If you like to read official patient pages while planning a consult, two clear overviews live here: Mayo Clinic on Laser Resurfacing and the AAD on Laser Hair Removal. They’re not brand-specific, which I find refreshing.

Little habits I’m testing that seem to shorten downtime

None of these are promises—just small, evidence-informed tweaks I log in my notes and discuss with a clinician before doing:

  • Pre-care “quieting”: pausing retinoids, exfoliants, and home acids 3–7 days before most light/laser sessions so the barrier is calm.
  • Sun discipline: two weeks of shade-seeking and broad-spectrum SPF 30+ before and after—nothing torpedoes outcomes like a fresh tan or post-procedure UV hit.
  • Antiviral if prone to cold sores: for perioral treatments (especially ablative), clinicians often prescribe prophylaxis. I add reminders to actually start it when told.
  • Moist wound healing after ablative passes: bland occlusive ointment, frequent reapplication, saline soaks, and avoiding “helpful” actives until the surface has closed.
  • Gentle cleansing gadgets off: no brushes or scrubs—just hands and a fragrance-free cleanser.
  • Smoke-free healing window: tobacco/nicotine constrict vessels and can slow recovery; I treat the week before and two weeks after as non-negotiable.

For structured how-to pages, I keep these bookmarked: MedlinePlus Laser Resurfacing Care and the ASDS Skin Resurfacing page.

Notes for skin of color and sensitive skin

Melanin is an excellent light absorber, which means darker skin can pick up energy even when it isn’t the target. That’s why device choice, parameter tuning, and test spots matter. Patterns I watch for:

  • Safer bets: long-pulse Nd:YAG (1064 nm) for hair and vessels; conservative non-ablative fractional (1440–1550) with lower densities; PDL with longer pulse widths and careful cooling.
  • Extra caution: 532 nm treatments and aggressive IPL can over-treat melanin. If used, I want an experienced operator and a clear test spot plan.
  • PIH prevention: diligent photoprotection, avoiding picking, and sometimes short-term topicals (e.g., azelaic acid) once the barrier is healed—only with professional guidance.

On the flip side, very sensitive or rosacea-prone skin may swell dramatically even with gentle settings. I build buffer days in my schedule and keep a simple routine at the sink: cool compresses, bland moisturizer, and sunscreen. When in doubt, I slow down and ask.

Yellow flags that make me pause and double-check

I keep a list on my phone so excitement doesn’t override judgment:

  • No eye protection: deal-breaker. Proper shields or goggles are non-negotiable.
  • Recent isotretinoin: timing matters; I confirm waiting periods with a clinician before ablative work.
  • Active infection, open cold sores, or dermatitis flare: reschedule rather than risk spread or PIH.
  • Promises of guaranteed results: biology varies; I want ranges and honest before/afters.
  • Push for aggressive first pass: I prefer test spots and stepped plans—especially for new operators, new devices, or new skin concerns.

If you want official wording on risks and benefits, the FDA overview and AAD patient pages are thorough without hype.

A day-by-day feel for the first week after common treatments

This is the rhythm I’ve felt and seen (always adjust to the instructions you receive):

  • Day 0: warmth, redness, and swelling. Cool packs wrapped in a clean cloth are soothing. Sleep on an extra pillow to nudge swelling down.
  • Day 1–2: PDL bruising deepens if present; non-ablative fractional feels “sunburn-y”; ablative has ooze that needs gentle cleansing and ointment. No picking.
  • Day 3–4: non-ablative bronzing shows; ablative crusts lift as fresh skin closes. Avoid workouts that chafe treated areas.
  • Day 5–7: most people are socially presentable after non-ablative and fractional ablative; lingering pink is common and make-up often OK if skin is sealed.

From there, collagen remodeling hums along for weeks to months. I set a reminder to take photos in consistent lighting every 4–6 weeks; the slow wins are easy to miss day to day.

What I’m keeping and what I’m letting go

I’m keeping my respect for the boring basics: parameter choices, patient selection, and post-care do most of the heavy lifting. I’m also keeping sun discipline and patch-test humility. What I’m letting go is brand fixation and the idea that more aggressive is always better. Good plans meet your calendar and your skin where they are.

FAQ

1) Is IPL the same as a laser?
Answer: No. IPL is filtered broad-spectrum light, not a single wavelength laser. It can treat pigment and redness with the right hands, but parameter finesse and eye protection are key.

2) How many days should I block off after fractional ablative CO2?
Answer: I plan a full week for initial healing (ooze → crust → fresh pink skin), then expect background redness that softens over a few more weeks. Exact timing depends on density/energy and your aftercare.

3) I have melanin-rich skin. Are lasers off-limits?
Answer: Not at all. Devices like long-pulse 1064 nm Nd:YAG and conservative non-ablative fractional options can be appropriate. The bigger variable is the operator’s experience and test-spot strategy.

4) Can lasers remove pores permanently?
Answer: Pores are anatomy. Some devices can reduce the appearance of large pores by smoothing texture or improving oil balance, but permanent “erasure” isn’t realistic.

5) Do I need antiviral medication every time?
Answer: If you have a history of cold sores and you’re treating areas near the mouth—especially with ablative resurfacing—many clinicians recommend short prophylaxis. It’s individualized, so ask beforehand.

Sources & References

This blog is a personal journal and for general information only. It is not a substitute for professional medical advice, diagnosis, or treatment, and it does not create a doctor–patient relationship. Always seek the advice of a licensed clinician for questions about your health. If you may be experiencing an emergency, call your local emergency number immediately (e.g., 911 [US], 119).