This question was posed by a hair loss sufferer seeking hair loss help on our hair restoration forum and answered by Dr. Michael Beehner of Saratoga Springs, NY who is one of our recommended hair restoration physicians. His professional answer is below.
My understanding is that it is normal to have shafts of transplanted hair fall out within weeks or a month, and that they will (hopefully) grow back after 3 to 4 months after the hair transplant procedure. I realize that not all heads are created equal but, on average, if there is such a thing, what is the percent of transplanted grafts that will continue to grow after transplanting without falling out first? Maybe it would better ask if it is common to have hair grow without falling out, or is it completely unheard of?
Your impression is correct, in that the great majority of the hairs that are transplanted (most of which are only 1/8th inch long) are shed during the first few months, before the “real” hairs appear 3-4 months post-operatively. They usually shed in one of two ways: some fall off with the scab at the 6-10 day point, while others just “sit in place” in the skin, even though down deep in the skin they are literally disconnected from the follicle (the living part of hair), which shrivels up and hibernates for that time period. These short stubs then can sit there for weeks or they can fall off at anytime. The best way to tell a “disconnected,” non-growing one from one that is going to grow is to simply look at it a couple of weeks later. If it is longer, then it is growing. It’s as simple as that.
I find that around 5% of hairs keep on growing from the day of the hair restoration procedure, and in some patients, this percentage is even much higher, but they are definitely the exceptions.
The other issue you alluded to was what percentage of the hairs that are transplanted actually survive and grow. Many studies have been done to look at this, some with tiny boxes out in the middle of bald skin, and others deep in the center of a thousand other sites, and the averages are somewhere around 90% survival for all follicular units (FUs), and around 99% for multi-follicular units (MFU) grafts (DFU’s and TFU’s). The FU studies range from the high 70’s to even higher than 100% (due to hidden telogen stage hairs that later grow). The percentage you receive from your doctor will depend on the skill of him/her and the staff more than anything. In two research studies I conducted, 1-hair FU’s did not survive as well as 2-hair FU’s. Again, the probable reason for this is the same as for why MFU grafts survive better – namely, because of the extra protection and buffering against the elements of drying and trauma that the extra tissue between the follicles provides.
Mike Beehner, M.D.