Why Underarm Laser Hair Removal in Hongdae Can Be Ineffective Even After 20 Sessions

Hello. I’m Dr. Jo Wonjin, and I’ve been treating skin conditions for 10 years.

I’ve had underarm hair removal 20 times,

but it still comes back like a sharp pencil lead ㅠㅠ

It was hard going through it for over a year,

so why won’t it go away?

The main reasons your underarm laser hair removal may not have worked can often be explained by these three factors:

1. Low-energy treatment

2. Too short a treatment time

3. Repeating the same method every time

Some people still keep growing hair even after more than 20 sessions.

As shown in the photo above, underarm hair tends to be thicker and stronger than hair on other parts of the body.

You may be wondering whether the device is not good or whether your body type is the issue.

Today, under the topic of why underarm laser hair removal in Hongdae can be ineffective even after 20 sessions, I’ll explain the following:

• How underarm laser hair removal works

• Three reasons laser hair removal can lose effectiveness

• Frequently asked questions about laser hair removal

I often hear concerns about hair removal results in the consultation roomㅎㅎ

How underarm laser hair removal in Hongdae works

Laser hair removal works by having laser energy absorbed by the melanin pigment in the hair, and that heat destroys the hair follicle.

There is one important point here.

Laser is effective only on hair in the growth phase.

Hair goes through a cycle of growth phase → regression phase → resting phase,

and hair in the regression or resting phase is hardly affected even if a laser is applied.

That is why the basic process of hair removal is to repeat treatments every 4 to 6 weeks,

and gradually target the hairs as they enter the growth phase.

Three reasons underarm laser hair removal in Hongdae can lose effectiveness

1. The hair is thick, but the energy level is too low

Underarm hair tends to be thicker and the follicles are deeper than in other areas.

To destroy the follicles of such thick hair, enough energy must be delivered accordingly.

However, in some cases, the treatment is performed with the output set too low because of concerns about burns or pain.

If the energy is too low, the heat cannot reach deep enough into the follicle,

so the follicle is not completely destroyed and only gets damaged before recovering again.

In the end, the pattern repeats: it seems to fall out for a short time after treatment, then grows back before long.

That is why you need a detailed evaluation first, and then a consultation about the energy output suited to your hair before starting treatment.

2. The treatment time is less than 1 minute

Because the underarm area is small, some places that finish quickly

can treat both sides in less than a minute total.

Proper hair removal requires the entire treatment area to be irradiated without gaps.

Because the underarm skin folds, it needs to be spread out flat and carefully treated,

and areas with high follicle density may also need overlapping passes.

Treatments that end too quickly can leave blind spots where the laser does not reach,

and the follicles in those areas remain untouched.

3. You keep getting treated the same way without doctor feedback

With each session, the condition of the hair changes.

At first, the hair is thick and dark, but over time it becomes finer, and the distribution of the remaining hair also changes.

Naturally, the output and treatment method should be adjusted accordingly.

• If the early sessions mainly targeted thick hair, later sessions need settings suited to finer hair
• If one specific area is especially resistant, the energy or number of passes for that area should be adjusted
• Depending on the progress across sessions, the device may need to be changed or used in combination with another method

If you keep receiving the same treatment every time without careful physician review, of course the effect will be limited, right?

I also have a lot to say about the way laser treatment is done,

and if you read the post below, you’ll understand why I’m emphasizing the points above.

Frequently asked questions about underarm laser hair removal in Hongdae (FAQ)

Q. Will getting it done more often improve the hair removal effect?

A. It is not always better to do it more often.

For the best results, you should keep the 4 to 6 week interval exactly, matched to the hair’s "growth phase" that the laser can destroy.

Q. Does hair removal make you sweat more?

A. Laser only destroys the hair follicles and does not affect the sweat glands, so it does not actually increase sweat production.

It only feels that way because without hair, sweat flows down more directly.

Q. Can I pluck hairs that grow in between sessions?

A. If you pluck the hair, the hair root (pigment) that the laser needs to target at the next session disappears, so you will not get any hair removal effect at all.

Never pluck it; you should only shave lightly.

Summary of the key points for underarm laser hair removal in Hongdae

If there is no effect even after more than 20 sessions, you should check the treatment method before blaming your body type.

Check item	Key point
Energy output	Is the output strong enough for the thickness of my hair?
Treatment time	Is the area being carefully treated without blind spots?
Doctor feedback	Are the settings being adjusted after reviewing progress each session?

If even one of these three is missing, the problem is not the number of sessions but the method.

Simply increasing the number of sessions when there is no effect can cause unnecessary stimulation and lead to issues such as pigmentation.

Please make sure to receive treatment at a place that gives a proper diagnosis and takes care with each session.

Thank you. This was Jo Wonjin.