How well you prepare for each session has a measurable effect on results. The two most common reasons sessions get rescheduled or rendered less effective are tan skin and improper hair length — both of which are 100% avoidable.

Here's the complete prep checklist, in order.

6 weeks before your first session

  • Stop waxing, threading, and plucking the treatment area. Hair removal that pulls the follicle out (anything except shaving) makes laser ineffective — there's nothing left for the laser to target. Switch to shaving exclusively starting now.
  • Schedule the consultation if you haven't. A reputable clinic does a free consultation and patch test before booking a package. Use this to confirm the laser type and ask about your specific skin/hair combination.

4 weeks before each session

  • No tanning beds. Tanned skin absorbs more laser energy and dramatically increases burn and pigmentation risk.
  • Avoid intentional sun exposure. Even a "light tan" can cause your clinic to reduce laser settings or postpone treatment. If you can't avoid sun (outdoor work, beach vacation), use SPF 50+ daily and stay out of peak sun hours.
  • No self-tanner or spray tans. Self-tanner pigment sits in the upper skin layers and confuses the laser. Most clinics require it to be fully washed off — which usually takes a week or two and several aggressive exfoliations.

2 weeks before each session

  • No medications that increase photosensitivity (when possible). This includes some antibiotics (doxycycline, tetracycline), retinoids (Accutane requires a 6-month gap before starting laser), and certain acne medications. Discuss anything you're on at the consultation.
  • Pause aggressive skincare. No retinol, glycolic acid, salicylic acid, or chemical exfoliants on the treatment area. Resume 1 week after each session.
  • Stay hydrated. Well-hydrated skin tolerates laser energy better and recovers faster.

1 week before each session

  • Confirm no sunburn anywhere on the treatment area. Burned skin is a no-treat — your clinic will reschedule, and you may forfeit the session if you don't reschedule yourself with advance notice.
  • Avoid blood thinners if possible. Aspirin, ibuprofen, and supplements like fish oil or vitamin E can slightly increase bruising risk. Acetaminophen (Tylenol) is fine.

24 hours before your session: the shaving rule

This is the single most important prep step. Shave the treatment area 24 hours before your appointment.

Why timing matters:

  • Shave too late (morning of): your skin may be slightly irritated, which makes the laser more uncomfortable and reactive.
  • Shave too early (3+ days before): hair will be too long when you arrive. Long surface hair absorbs laser energy above the skin, which (a) reduces the energy reaching the follicle and (b) can cause surface burns or singeing.
  • Shave 24 hours before: stubble is gone, skin is calm, and the laser energy goes straight to the follicle target.

Some specifics:

  • Use a fresh razor. Old razors irritate skin and miss patches.
  • Shave with the grain to avoid bumps.
  • Don't wax, depilate, sugar, or pluck. Shaving only.
  • Don't apply lotion, oil, or fragranced products to the area after shaving.

The "are you supposed to shave before laser hair removal?" question gets asked every day on social media. The answer is yes, always. The clinic expects to see clean, shaved skin when you arrive.

The day of your session

A few hours before:

  • Shower — clean skin, no residue
  • Don't apply deodorant, lotion, perfume, oil, or self-tanner on the treatment area
  • Drink water — well-hydrated skin handles laser better
  • Eat normally — laser sessions aren't long enough to need fasting prep

30–45 minutes before (optional):

  • Apply numbing cream if you're using it. Standard protocol is 4–5% lidocaine cream, applied in a thick layer, covered with plastic wrap. Lasts about an hour of numbness.

Important: don't apply numbing cream over a large area. Lidocaine absorbed systemically from full-body application has caused serious complications. Stick to one or two areas at a time, never the entire body.

  • Take ibuprofen (200–400 mg) if you're pain-sensitive. Skip if you're a frequent bruiser.

Right before the appointment:

  • Wear loose, comfortable clothing — especially over the treatment area
  • Bring your aftercare items if you'll be heading directly elsewhere — aloe, fragrance-free moisturizer, SPF 50+ for any exposed treated skin
  • Be honest about medications and sun exposure. A clinic that knows about a recent sunburn or a new antibiotic can adjust the settings. A clinic that doesn't know is more likely to over-treat.

Special prep notes by body area

Face / upper lip / chin:

  • Skip moisturizer or makeup on the area that morning
  • Numbing cream is more commonly used here

Underarms:

  • Skip deodorant the morning of (apply normally only after the session is done and skin has calmed)
  • Numbing cream rarely needed

Bikini / Brazilian:

  • Trim to about 1/8 inch with scissors if your hair is very long, before shaving
  • Schedule outside your menstrual cycle if pain sensitivity is a concern
  • Wear loose pants or a dress to the appointment

Legs:

  • Shave the night before (24 hours), not the morning
  • Long sessions — bring earbuds and a podcast

Back:

  • You'll need help shaving — ask a partner or pay for a quick prep wax at a salon (only if you can't shave it yourself, and only with shave gel — no actual waxing)

What to expect at check-in

  • The technician will inspect the treated area for tan, sunburn, or visible irritation. If any of these are present, they'll reschedule.
  • They'll confirm your shaved status and may touch up missed patches with a clinic razor.
  • They may take baseline photos (especially at session 1) to track progress.
  • They'll wipe the area with a cleanser and apply a thin layer of conducting gel for some lasers.
  • You'll wear protective eyewear during treatment. Don't peek under it during pulses.

Why prep matters for results

The two most-cited reasons sessions feel less effective:

  1. Tanned skin → clinic reduced the laser energy to avoid burning → fewer follicles disabled per session → you need more sessions overall
  2. Hair too long or too short → laser energy absorbed in surface hair or skipped the follicle entirely → that session contributed almost nothing

Both are entirely avoidable. Following this checklist is the difference between getting the full value out of a $1,000+ package and effectively wasting a session or two.

When to reschedule

Reschedule the appointment (most clinics will move you without a penalty if you give 24 hours notice) if any of:

  • You have a sunburn or significant tan on the area
  • You're on a new antibiotic or photosensitizing medication
  • You're sick with a fever
  • You've had a chemical peel or microneedling on the area within 2 weeks
  • You can't get the treatment area shaved properly in advance

A clinic that pressures you to keep the appointment when one of these applies isn't acting in your interest.

Booking your next session

A well-prepared session is uncomfortable for 5–25 minutes and produces visible results within 2 weeks. A poorly-prepared one is uncomfortable, less effective, and possibly damaging. The checklist above takes maybe 30 extra minutes of effort across the week before your session.

Browse vetted providers in your city if you haven't booked yet, and bring this guide to your consultation — it'll show the clinic you've done your homework.