Can a FUE hair transplant damage existing hair follicles?

It is absolutely possible to damage existing hair follicles with any hair restoration procedure whether it be the strip or the FUE.  In an FUE procedure, care needs to be taken in regards to grafts extraction, small punch size, and minimal punch depth.  Also, over harvesting of grafts can create vascular trauma and lead to significant irreparable damage to the donor zone.  Recipient site creation is also important.  Sites need to be as small as they can be (matching the grafts) as well as care being taken not to hit the surround follicles while creating the sites.  With an experienced surgeon you should have no problem.

Dear ryanSAThanks for the question. The points among hair shafts for inserting the follicles are incised by microsurgical technique with the help of magnifier equipment. There is no risk regarding this procedure for those patients with an apparent thinning, who have non-hairy scalp large enough among the follicles.
Considering the risk of doing harm to existing hair, hair transplant is not recommended for those individuals who are experiencing the beginning stages of hair loss and whose hair does not show an apparent thinning. In such cases, medical treatments are tried first. I wish you all the best.

Yes it is possible to damage existing hair follicles and even have shock hair loss associated with surgery.  All surgeries have its risks and benefits.  The decision to have surgery is based on the benefits outweighing the risks.

This question accentuates the importance of the making of recipient sites and the involvement of medical decision making to assure you are treated not just as someone in whom to put in hair grafts, but also have your hair loss properly diagnosed and a plan made for the future.Great you are on Propecia, and you need to realize that there are some challenges in working between already existing hairs, but the risks can usually be minimized by careful techniques.

If FUE procedure done correctly, it should not damage the existing hair. We have different punch sizes for hair transplant and different devices to extract the grafts. These methods may change based on the type of recipient or donor hair you have to avoid any damage to your donor or recipient hair.