In short: One session is not enough. At Swiss Derma Clinic, four to eight treatments are usually appropriate depending on hair and skin type, spaced four to eight weeks apart. In individual cases it can be fewer or more, because body area, hair colour, hair thickness and hormones all play a part. „Permanent“ here means a long-term reduction in hair growth, not a promise that no hair will ever grow again.
Why one session is not enough
In laser hair removal, the pigment melanin in the hair absorbs the light energy. This creates heat, which damages the hair follicle. It works mainly on hairs in the active growth phase.
Not all hairs are in this phase at the same time, so each session only reaches some of them. Follow-up appointments are meant to reach the hairs that were resting last time. That is why you need a series with intervals rather than one stronger treatment.
What the number of sessions depends on
Four to eight treatments is a guide, not a fixed plan. We discuss roughly how many sessions you are likely to need after examining the areas concerned. These factors influence the assessment:
- Hair colour: Dark hair absorbs the light energy best.
- Hair thickness: Coarse hair usually responds better than fine hair.
- Skin: Your Fitzpatrick skin type determines the choice of settings. Darker skin can also be treated if the method and experience are right for it.
- Body area: Laser hair removal on the legs does not have to follow the same plan as treatment on the face.
- Hormones: Hormonal fluctuations and hormone-containing medicines can stimulate hair growth and make additional appointments necessary.
The limit with light hair
White, grey, blonde and red hair contains little suitable pigment and does not respond reliably to laser treatment. More sessions do not simply make up for this. Before starting a longer series, check whether your hair is suitable for the treatment.
Preparation and the first session
For the treatment to work, the hair root must stay in the hair shaft. The main points before your appointment:
- Stop plucking, waxing, epilating and sugaring at least three weeks beforehand. You can still shave.
- Do not bleach or lighten the hair.
- Avoid intense sun and tanning beds in the days before and after, and use sunscreen with SPF 50.
- Shave the areas the evening before. On the day of treatment, the skin should be freshly washed and free of make-up, deodorant and sunscreen.
- Mention any tan, previous problematic scars, recurring cold sores and all medicines and supplements during the consultation. Please do not stop any medication on your own.
Allow about an hour for your first session, including preparation and aftercare. Our team checks the treatment areas as well as pigment changes and moles with a dermatoscope and covers them if necessary. The laser pulses can feel like brief warm pinpricks, and the cooling on the device eases the sensation of heat. Suitable eye protection is essential.
Afterwards, redness, swelling and sensitive skin are possible. Blisters, pigment changes, burns or scars occur rarely. Please contact us if you develop blisters, crusts or severe discomfort so that the skin can be assessed before the next appointment. You can return to work the same day.
The treatment timeline
The ideal interval is usually four to eight weeks and depends on the natural hair cycle, the body area and how your skin reacts. As an example: six sessions six weeks apart add up to around seven months from the first appointment to the last. So plan for the series to take several months.
| Stage | When | What happens |
|---|---|---|
| Consultation | Before starting, ideally at least three weeks before the first session | Assess skin and hair, clarify suitability and expectations |
| First session | Day 0 | Check the areas, treatment, aftercare advice |
| First week after | Days 1 to 7 | Be gentle with the skin, reduce direct sun or cover the areas |
| Hair falls out | Days to a few weeks after | Do not pluck the hairs, the body sheds them on its own |
| Follow-up sessions | Every four to eight weeks | Review hair growth and tolerance, set the next interval |
| After the series | Depending on regrowth | Assess the result, discuss a touch-up if needed |
If there is hardly any change after several treatments, suitability should be reviewed. Further appointments without assessing the result so far achieve little.
What „permanent“ means
The aim is to reduce hair growth in the long term. Many patients remain largely hair-free for months or even years after a series. Most will eventually notice some regrowth, though these hairs are often finer, lighter and fewer in number. A touch-up can then be useful. There is no fixed annual appointment, however: what counts is the actual regrowth.
Women’s facial hair is a special case. With laser hair removal on the face, hormones have a strong influence, so a permanent result like that on most other parts of the body cannot be expected there. The upper lip and chin can grow hair again even after a successful series.
When a medical assessment matters
Heavy hair growth is not always just a cosmetic issue. If women develop thick, dark hair on the face or body along with irregular periods, the cause should be investigated. If strong dark hair growth starts suddenly or your voice becomes deeper at the same time, a prompt medical examination is important.
At Swiss Derma Clinic in Zurich, laser hair removal is carried out by experienced practitioners under medical guidance or by the dermatologist. Before treatment, we advise you, analyse your skin and hair type and discuss what result and roughly how many sessions you can expect.
Frequently asked questions
Are six sessions always enough?
No. Six sessions are within the usual range but do not guarantee a particular result. Some courses need fewer appointments, others more. It depends on your skin, your hair, the body area and how you have responded so far.
Can I shorten the intervals?
Please do not change the intervals on your own. The appointment should fit both hair growth and the skin’s recovery. More frequent laser sessions do not automatically reach more hairs. Discuss preferred dates and planned trips early on.
Can I shave between sessions?
Yes, you can shave. The skin is more sensitive for a few days straight after treatment, though. Avoid plucking, waxing and epilating throughout the series, because these remove the hair root that the laser targets.
Do extra sessions help with light hair?
Usually not reliably, because the suitable pigment is missing. Have it assessed beforehand whether a series is worthwhile for you and, if necessary, discuss another method of hair removal.
How do I find out my personal schedule?
You will receive an initial assessment after your skin and hair have been examined. It is then reviewed according to how you respond. You can find more about what we offer on our laser hair removal in Zurich page.
This article does not replace a medical examination.





