How Much Hair Should Fall Out After Session of Laser Hair Removal (Bikini)?

I've had one session 2 weeks ago. It seemed like a really quick session. I've had a few hairs fall out - once they fall out, are they permanently gone? Do hairs continue to fall out over time, and I won't really know how effective the treatment was for weeks yet? Or should all the hair fall out the first time, and then a portion regrows, and that's when you do your next session?

Doctor Answers 10

Laser Hair Removal

We suggest to spread your laser hair treatments 4-6 weeks apart based on the hair growth cycle. With each treatment the active growing hair is destroyed, creating less of a blood supply to the follicle, making the hair that grows back weaker and thinner. Ideally every hair in the treatment area will die and fall out with each treatment.

New York Dermatologist
4.4 out of 5 stars 5 reviews

Hair removal treatments require multiple treatments

Don't expect to have all the hair fall out after just one laser or IPL hair removal session. Multiple treatments are required because hairs cycle and only actively growing hairs are effected with each treatment. Expect to do at least six treatments about 3-4 weeks apart.

Dina D. Strachan, MD
New York Dermatologist
3.3 out of 5 stars 10 reviews

Hair Reduction After a Session of Laser Hair Removal

The amount of hair that falls out at each session of laser hair removal can vary. Hairs grow in 3 different phases, and laser hair removal is effective against hairs in the growing phase. If the hairs are in the correct phase, they should be permanently reduced. Some hairs can be ejected from the follicle immediately, while some can continue to grow and fall out over the next few weeks. We usually recommend neck and face treatments to be done every 4 weeks and any body area below the neck every 6 weeks so that the hairs will hopefully be in the correct phase for laser hair reduction. Some treatments will yield a lot of hair removal while others will result in very little hair removal. It just depends on the phase of growth.

Laser hair removal and fall out

appropriate laser hair removal involves shaving of the hair so that there is no hair shaft sticking high above the surface, otherwise too much energy may be absorbed by the epidermis and the skin could get burned.  Therefore, within two weeks you shouldn't see hair fall out because it was already shaved off.  The hair that grows out will take some time to do so and will shed probably without your seeing it.

Ronald Shelton, MD
Manhattan Dermatologic Surgeon
4.9 out of 5 stars 37 reviews

How much hair falls out with each treatment?

Ideally, every hair in the growth phase will fall out or shed after a laser hair treatment.  Since not all hair is in the growth phase, only a portion of the hair can be removed during each session.  Each treatment should either have less hair or finer hair from previous treatments.  

Anil R. Shah, MD
Chicago Facial Plastic Surgeon
4.8 out of 5 stars 143 reviews

Laser Hair Removal

The amount of hair that falls out after each treatment is 15%-20%. Laser hair removal is done when the hair is in its growth phase. An area with a faster growth cycle (like bikini area) can be treated every 4 weeks. An area with a longer growth cycle (like the legs) can be treated every 6-8 weeks. Continue your treatment to see maximum results

Hardik Soni, MD
Summit Emergency Medicine Physician
5.0 out of 5 stars 22 reviews

Laser hair removal is long-term hair removal over time

Thanks for your question. Laser hair removal is long-term hair removal over time and with each treatment
there should be loss of hair that is significant. Hair removal lasers can also work on the active growing
hairs for the most part and therefore, this is why several treatments are needed to have this work the way
we all want it to work. There are a vast variety of laser hair removal devices out there and the provider
needs to choose the appropriate device to make sure that you are receiving the most appropriate
treatments. The most commonly used treatments today are from the Lumenis LightSheer Duet and the
Alma Soprano ICE for the diode lasers, and there are many Nd: YAG lasers for those with darker skin
needing these lasers.
The fact that you have not seen that much of a result in 2 weeks should not dismay you. Continue with
the treatments and you will see the results that you are wanting. And make sure that you are seeing the
proper provider – that’s very important.

Michael Gold, MD
Nashville Dermatologic Surgeon
3.9 out of 5 stars 17 reviews

About 20% should be removed during one session

You should see at least 20% of the hair fall out after each session. If you only had a few hairs and your session was short I’m assuming that your treatment wasn’t done properly or the laser wasn’t set at the right parameters. The hair on the bikini area is usually dark and thick so it should work faster and better. You still need to do at least six sessions for the best results, but you should notice a big improvement after each treatment. We use Lightsheer Duet which I think is the best tool on the market right now

Laser Hair Removal Requires Several Treatment Sessions

In general, two or more treatments are required at each site to achieve permanent hair removal. The laser is only effective when the hair follicle is in its active growth phase. Repeat sessions will be necessary to treat those follicles when they re-enter the growth phase. Optimal long-term benefits depend on the area you wish to have treated, the hair density, and your hair’s growth cycle. Darker hair responds best to the laser, while lighter hair is less responsive. Age, ethnicity, diet, hormones, medication, and metabolism all play a part in your hair’s location, thickness and resilience. You may be right to be concerned about a really quick session. You should discuss this with your treating physician.

Mitchell Schwartz, MD
South Burlington Dermatologic Surgeon
4.6 out of 5 stars 11 reviews

Hair fallout after laser hair removal

All the hair that was effectively treated in that laser hair removal session should fall out around the same time. If you had a short treatment session and are now only seeing a little bit of hair fallout, then you may have correctly assumed that your treatment was not comprehensive. 

Your sessions should be timed according to the type of laser being used.  Also, keep in mind that blonde, red, and gray hair generally does not respond to laser hair removal, so you won't see them fall out. 

the hair that falls out is permanently gone, but you have remaining follicles that can be activated throughout your lifetime, so you can expect permanent hair reduction, but not permanent hair removal.

Carmen Kavali, MD
Atlanta Plastic Surgeon
4.5 out of 5 stars 39 reviews

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.