Pre-Session and Post-Session Care

Status: draft compiled 2026-04-20.

The instructions a patient receives before and after a laser session are the single most operator-independent source of variability in outcomes. A patient who follows them carefully will have a better course than the same patient who doesn't, regardless of clinic choice. This chapter pulls the standard instructions together with the reasoning so the patient can follow them for the right reasons rather than by rote.

4-6 weeks before

Stop waxing, sugaring, threading, tweezing, plucking, and epilator use. The 4-6 week window is the minimum time for a waxed or plucked follicle to re-enter anagen with a new shaft in place. Laser without a shaft in the follicle treats empty follicles; the session is largely wasted. See ../../shortterm-deep/interactions-with-permanent-methods.md for the full sequencing rules. Shaving is fine and preferred.

Avoid tanning and UV exposure. Tanning concentrates melanin in the epidermis, which competes with follicular melanin for beam absorption and narrows the safety envelope. Self-tanners produce the same effect. The 4-week pre-session window should be sun-protected; mineral sunscreen SPF 30+ with iron oxide (for visible-light protection in darker skin types) is appropriate.

Plan facial home devices. Home IPL or home diode users should pause their home device 2-4 weeks before the in-clinic session. Continuing home use during the course is generally fine for inter-session maintenance; most clinics want to know what the patient is using.

Sources: ASLMS practice guidance; Dierickx 2000 Dermatol Clin, PMID 10903915. Confidence: C1.

1 week before

Hold topical retinoids. Tretinoin, adapalene, tazarotene (longer hold, 7-14 days). Retinoids thin the stratum corneum and reduce the epidermal safety margin; holding them allows the skin to recover some barrier function before the session. Restart 3-7 days post-session after all visible erythema has resolved.

Hold AHAs / BHAs in the treatment area. Glycolic acid, salicylic acid, lactic acid — same rationale as retinoids. 3-5 days typical.

Note any new skin condition — fresh sunburn, active cold sores, active acne flare, dermatitis, new suspicious mole or skin lesion. The clinic will often reschedule rather than treat over active skin pathology.

Confidence: C2.

24 hours before

Shave the treatment area completely. Clinics require that hair be at or below the skin surface at the time of the session. Leaving visible stubble produces superficial heating and burns because the beam heats the above-surface shaft rather than the follicle. Electric razor or blade razor; no plucking, waxing, threading, or trimming-with-root-removal.

For HSV-positive patients treating perioral or genital skin: start valacyclovir 500 mg BID × 10-14 days, beginning the day before the session. See ../complications/hsv-reactivation.md.

Skip caffeine and heavy exercise 2-3 hours before if pain control is a concern; caffeine and cortisol elevation can modestly increase perceived pain during the session. Ibuprofen 400-800 mg 30-60 minutes before is common and reasonable.

Confidence: C3.

Day of session

Arrive with clean, shaved, product-free skin. No deodorant, no makeup, no moisturiser, no sunscreen on the treatment area. The cooling plate or cryogen spray needs direct skin contact; products on the skin can reduce cooling efficacy and in rare cases interact with the beam.

Wear comfortable loose clothing to minimise post-session friction over the treated area.

Bring topical anaesthetic if the clinic doesn't provide it and if you've requested its use. See anaesthetics.md for the systemic-toxicity caps on lidocaine that limit how much cream can safely be used over a large surface area.

Confidence: C3.

Immediately post-session

Expect mild erythema and perifollicular edema. This is the desired endpoint. The skin may feel warm for 1-3 hours. Small pink-red bumps around follicles are the visible sign of beam delivery reaching the follicle.

Cool compresses or an ice pack reduce discomfort in the first hour. Avoid direct ice on the skin; wrap ice in a clean cloth.

Apply a bland emollient (petrolatum, Aquaphor, CeraVe, Cetaphil). Avoid fragranced lotions, AHAs, BHAs, and retinoids for 3-7 days.

A low-potency topical steroid (hydrocortisone 1-2.5%) is reasonable if erythema is moderate or perifollicular edema is pronounced. A medium-potency steroid (triamcinolone 0.1%) briefly is acceptable for strong reactions; avoid high-potency steroids on face and genital skin.

Do not rub, scrub, or exfoliate the treated area for 3-7 days.

Sources: Lanigan 2006 Dermatol Surg, PMID 16816888; Ali & Shukla 2025. Confidence: C2.

24-48 hours post-session

Avoid hot showers, saunas, swimming pools, hot tubs, and intense exercise. Heat and sweat in the treated field can provoke folliculitis on the freshly-wounded follicles. Lukewarm showers only; no immersive hot water for 48 hours.

Strict sun avoidance for at least 2-4 weeks. Mineral SPF 30+ reapplied as needed if sun exposure is unavoidable. For face treatments, a wide-brimmed hat is more reliable than sunscreen.

Watch for late-onset complications — blistering (within 24-48 hours is burn; contact the clinic), persistent severe erythema beyond 72 hours, developing PIH over 1-4 weeks (strict photoprotection, start topical pigmentation regimen), HSV reactivation (contact clinician if perioral/genital vesicular eruption). Shedding of treated hairs over 5-14 days is normal and desired; this is the beam's effect playing out.

Confidence: C3.

Days 5-14 post-session

Exfoliate gently starting around day 5-7, once all visible skin reaction has resolved. Shed hairs come out with a gentle washcloth or in the shower; helping them release prevents mild folliculitis from retained damaged shafts. Glycolic acid 8-15% daily is reasonable at this stage; resume retinoids.

Do not pluck or wax any new hair that appears — maintain shaving-only from the day before the next session.

Shave between sessions as needed for cosmetic maintenance. This is explicitly permitted and does not compromise the next session.

Confidence: C3.

Between sessions

Continue shaving only. No waxing, sugaring, threading, tweezing, plucking, epilator, or home IPL within 4 weeks of the next session. Home IPL during the inter-session gap is generally fine if the user already owns one; most clinics prefer patients not use home IPL during the course because it complicates parameter adjustment.

Avoid sun exposure in the treated field throughout the course. One deep tan in the middle of a course can force parameter reduction that adds 2-3 sessions to the total, offsetting months of incremental progress.

Retinoid and AHA/BHA use resumes between sessions with the hold-window discipline maintained: stop 3-7 days before the next session, restart 3-7 days after.

Confidence: C3.

Red flags to contact the clinic

• Blistering within 24-48 hours of a session.
• Severe, spreading erythema beyond the treated field.
• Persistent pain beyond 24 hours.
• New pustules or widespread folliculitis.
• New vesicular eruption suggesting HSV reactivation.
• New or changing pigmentation in the treated field 1-4 weeks post-session.
• Any visible crust or scab that doesn't heal within 7-10 days.
• Worsening symptoms rather than improving over 72 hours.

Confidence: C2.