Hair Regrowth
A very common question that we hear from patients is, How long will it take for hair to regrow? The answer is fairly simple in almost all cases of hair loss or after a hair transplant: for the most part, we all follow a very similar hair growth cycle.
Although there can be many reasons why hair is falling out, it is pretty standard that you can expect hair to grow back within the same time period.
A hair strand starts to grow from the root, otherwise known as the follicle. Hair feeds off of our blood supply. That is where the nourishment that is necessary for a healthy and growing hair comes from. Hair typically will take years to grow from start to finish. Over those years, hair will complete 4 stages of growth before it falls out.
The 4 Stages of Hair Growth
- Anagen (growth phase) – This phase typically lasts 2 to 7 years and will determine the overall length of your hair. Most people will regrow hair at a length of 6 inches per year.
- Catagen (transitional phase) – This is the stage where the reset button gets pushed on your hair regrowth. Usually the hairs that are transplanted will enter into this phase after a hair transplant. This stage will typically last 10 days as the hair follicle shrinks and detaches from the dermal papilla. This is why we can expect that the hairs from the transplanted follicles will start to fall out at about 2 weeks post-op.
- Telogen (resting phase) – This phase lasts about 3 months. Roughly 15% of your hair is in this phase at any given time. That is why it takes 3 months to see the new hairs starting to regrow after a hair transplant.
- Exogen (new hair phase) – This is the part of the resting phase where old hair sheds and new hair begins to grow. It is an expected level of hair loss to be roughly 50 to 100 hairs per day while in this phase.
Some types of hair loss can alter this cycle, however. With telogen effluvium, the hairs will enter into the resting phase too early, so more hair will be lost all at once instead of at the normal cyclical times. The good news though about hair that is lost due to telogen effluvium is that if the trigger for the hair loss is found and treated, the hair cycle will adjust to its regular cycle and the hair will start to grow back.
Catagen effluvium is a form of hair loss that is mostly seen in cancer patients who are receiving radiation therapy. This is when the hairs enter into the transitional phase all at once and therefore fall out and don’t regrow. But once this cycle can be reset, the hair will grow back. Some people have noticed that the hairs may grow back a different colour or texture than their original colour and texture.
