Laser prep is not complicated, but every item on the list exists for a specific reason. Understanding the why makes it much easier to remember.
Before Your Appointment
Shave the treatment area. Required, not optional, more on why below.
Arrive with clean skin. No lotions, oils, or products in the treatment area.
Avoid tanning. Before your treatment and throughout your entire course.
If treating the face, pause Retin-A and similar products for at least 3 days before your appointment.
Do not numb the treated area. Come to your appointment without numbing cream applied.
Tell your technician about any changes, to your skin, medications, skincare routine, or anything else. We adjust accordingly. This is not a formality; medications and actives genuinely change how skin responds to heat.
Why You Have to Shave Before Laser
The simple version: laser works by targeting and burning the melanin (pigment) in the hair follicle. If the hair is not shaved and is sticking out above the skin, some of the laser energy gets absorbed by the hair outside the skin instead of traveling down into the follicle where it needs to work.
If your hairs are very fine, this matters less. But if you have thick, coarse hair, unshaved hair meaningfully wastes energy that should be reaching the follicle.
Why one day before, not the morning of?
In case you accidentally nick or cut yourself while shaving.
Giving your skin 24 hours allows small cuts to heal. If you shave right before your appointment and cut yourself, your technician cannot safely treat that area and will have to skip that spot, which means paying for a session that misses part of your target area.
Why You Can't Wax, Pluck, Tweeze, or Sugar
Laser targets the pigment inside the hair follicle. When you wax, tweeze, pluck, or sugar, you remove the entire hair from the follicle.
No hair, no target. Those follicles cannot be treated during your session, which slows your progress and often means more sessions overall.
Shaving is the only method to use between laser appointments. It cuts the hair at the surface while leaving the follicle intact.
If you have recently waxed and want to begin laser, wait about two weeks, or until you can see enough hair growing back for the laser to target.
Why Tanning Is a Problem
When you tan, your skin produces more melanin in its most superficial layer.
Since laser targets melanin, more pigment in the skin makes it harder for the laser to distinguish between the hair and the surrounding skin, which increases the risk of skin damage.
Apply sunscreen daily and protect the treated areas from tanning between sessions. This is true for every skin tone, but it matters most for clients with more melanin, where a burn carries a higher chance of leaving hyperpigmentation behind.
During Your Session
A note on comfort and settings, since clients often wonder what "should" happen.
With laser, higher settings do produce better results, the stronger the laser, the more effectively the follicle is destroyed. But because there is a real risk of burning, settings have to increase gradually rather than starting high.
We aim for the highest comfortable setting you can tolerate. A good way to gauge this is a 1–10 comfort scale. If you are consistently below a 6, there is usually room to increase the setting.
Our Candela GentleMax Pro has a built-in cryogen cooling system that cools the skin before the laser's heat reaches it, and we use cold compresses during treatment to help minimize heat spread into surrounding skin.
After Your Treatment
Avoid anything hot for the rest of the day. This is the main rule.
That means:
- No hot showers
- No saunas
- No hot tubs
- No intense exercise
Heat and sweating irritate freshly treated skin, and can bring back reactions that had already settled.
Continue avoiding tanning throughout your treatment course, and wear sunscreen daily.
Keep the skin clean and skip heavy oils or pore-clogging products on the treated area.
Normal Reactions and What They Mean
Hives. Hives after laser are normal and common, especially during your early sessions, and they can be a positive sign. It means the laser successfully targeted the follicle. The follicle essentially exploded inside the pore, causing temporary bumps and hive-like swelling that last a couple of minutes.
If you apply heat the same day, these reactions can return and may feel itchy. This is the specific reason for the no-heat rule.
Hair "growing back" a few days later. This is the most common panic call I get, and it is not what it looks like. Those are usually dead hairs shedding from the follicle, not new growth.
Because the hair is shaved before laser, when the laser targets the follicle the treated hair inside the skin can start pushing out and shedding. This is completely normal. You will notice the true reduction closer to your next appointment as treated follicles continue shedding and stop producing hair.
Acne. Uncommon and rare, but it happens. Heat from the laser can affect bacteria naturally present on the skin, and if the skin was not properly cleansed beforehand it may contribute to temporary breakouts lasting a few days. The fix is the prep list: clean skin, no heavy oils or lotions before treatment.
Quick Checklist
24 hours before: shave the area.
Day of, before you come: clean skin, no lotions or oils, no numbing cream, no fresh tan. Face clients, no Retin-A for 3 days.
Rest of the day after: no hot showers, saunas, hot tubs, or intense exercise. Sunscreen going forward.
Between sessions: shave only. No waxing, tweezing, plucking, sugaring, or tanning. Note how often you are shaving: we will ask.
Related reading
- Can You Shave, Wax, or Tweeze Between Hair Removal Sessions?
- Is Laser Hair Removal Dangerous? Radiation, Burns, and Other Myths
- How Many Laser Hair Removal Sessions Do You Actually Need?
Have a question this didn't answer? Book a free consultation at our Midwood, Brooklyn studio or call 718-360-2902. We'll look at your hair and skin, answer everything, and build a plan with you.