I sometimes hear from people who have been suffering from telogen effluvium hair loss who worry that their hair follicles have been damaged and, as the result, will be unable to produce healthy or normal hairs once again.
Common comments are things like: “I’ve had hair loss for over a year. During that time, my regrowth was thin and it kept falling out so that it never had the chance to regrow normally. Now, the shedding seems to have stopped. But I’m worried about my regrowth. Will my follicles be able to produce normal and healthy hair again? Or, have they been damaged from this process? I have an awful feeling that I’m going to regrow thin, sickly, flyaway hairs.”
I’m certainly not a medical expert, but in my own experience and observation, as long as the triggers that kicked off the shedding in the first place have been removed and you have no other scalp or hair loss issues, then normal hair cycles (including regrowth) should eventually resume. Sometimes, people worry that their scalp or ability to regrow hair has been negatively affected because they see their new hair fall out or they notices that it looks thin early after recovery. Sometimes, the new hair has to grow a few inches in length before it begins to reach a normal diameter. Also, it is possible to need a couple of shedding cycles before your normal hair cycles resume.
If your hair is a couple of inches long or you’re still seeing things that worry you for a couple of months after recovery, then there are a couple of other possibilities. The first is that the original trigger has returned or a new trigger has come up. If your hair loss is due to medical issues, then it’s possible that they are not completely resolved. Another possibility is the inflammatory process. Rapid and drastic hair shedding and regrowth can sometimes cause an inflammation process in your scalp your can affect your regrowth. If this is the case though, you’ll often see a reddish or pink scalp that feels tight or itches.
If you’ve ruled these things out, ask yourself if it’s possible that the telogen effluvium was instead an androgen driven process. Androgen driven hair loss or androgenetic alopecia is the most common form of hair loss, even for women. And one of the symptoms of this type of hair loss is a scalp and hair follicles that struggle to regrow and maintain healthy hair because of the excess androgens (or your body’s reaction to normal androgens.) So if you’ve given your regrowth plenty of time and you’re still seeing things that make you worry, then it might be a good idea to explore if your hair loss is androgen driven. Also, some hair loss starts out as an effluvium and eventually turns into androgen driven loss as soon as the person reaches the age where the androgenetic alopecia would have begun in the first place.
So to answer the question posed, it’s my experience that the follicles are not negatively affected by shedding in the long term. While it’s possible for hair to look different when it is still short and it’s not uncommon to have a few abnormal cycles before normal patterns resume, follicles should behave normally several months after the shedding is over. If they aren’t, then it’s important to see if there are any other possibilities (like inflammation, medical issues, or androgens) that need to be addressed.