Does Laser Hair Removal Only Works for Hair in the Anagen Phase?

I've never shaved my arms because I'm afraid it'll appear thicker when it grows so since the hair was there for many years, it should be in the telogen phase then? Will shaving it now make it into anagen phase?

Doctor Answers 4

Laser hair removal

Shaving or other external hair removal such as depilatories will not cause hair to grow back darker or longer. That is a myth.

As you may have heard, the actual hair is dead tissue. Only the root is living. Also, don't try to change the hair growth cycles. We really can't do much about that either.

If you are getting laser hair removal, just be patient and confident. This process really does work. It just takes time.


Nashville Dermatologic Surgeon
5.0 out of 5 stars 1 review

How laser hair removal works

With multiple Laser hair removal treatments, significant long-term hair reduction can be achieved. In general, two or more treatments are required at each site. 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.
Removing hair does not make it grow back thicker, darker, or quicker. The opposite is usually the case.


Mitchell Schwartz, MD
South Burlington Dermatologic Surgeon
4.7 out of 5 stars 12 reviews

Laser Hair Removal and Hair Phases

Shaving the hair on your arms will not cause it to grow back thicker. In a way, it does feel like thick prickly stubble when it first starts to grow back. But at a certain point during the growth, the strands taper off and no longer feel this way. So it might be easier to understand how this myth came to be. In the context of laser hair removal, shaving is actually quite beneficial for the procedure. The treatment does work better for hair in its active growth phase (anagen). This actually helps minimize the pain from the procedure. Also, during the anagen phase, melanin is more abundant. Melanin is needed to absorb the laser energy which then affects the hair follicle causing it to enter a resting phase. 

Sanusi Umar, MD
Redondo Beach Dermatologic Surgeon
4.6 out of 5 stars 32 reviews

Laser Hair Removal

Shaving unwanted hair will not cause the hair to grow back thicker.  I recommend that my patients shave any areas that they want to treat with laser hair removal before their appointment.  The laser hair removal will work best if the hair is in the active growth cycle also known as the anagen phase.  Treatment should be done every four, six or eight weeks depending on the area of the body being treated to ensure that the hair follicles will be lasered during the anagen phase.

Michele S. Green, MD
New York Dermatologist
5.0 out of 5 stars 75 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.