Shock loss after a hair transplant: Why does it happen, and is it permanent?

What is shock loss?

Shock loss is the temporary loss of some of the transplanted hair, or of the hair around it, in the weeks after a hair transplant. When and to what extent it happens varies from person to person.

In everyday use, the term covers two separate things: the shedding of the transplanted hairs, and the loss of your own hair that was already in or around the recipient area. In medical sources, the term “shock loss” or “postoperative effluvium” (temporary shedding after a procedure) is mostly used for the second; the shedding of the transplanted hairs in the first weeks is considered an expected part of the process. It is important to tell the two apart, because they do not always follow the same course.

In both cases, the underlying process is similar: the hair falls out, but the follicle (the root that produces the hair) often stays in the skin and, after a resting period, starts producing hair again. In other words, when a hair falls out, it does not necessarily mean that its root has been lost too.

Why does shock loss happen?

Every follicle follows a cycle made up of growth (anagen), transition (catagen) and resting (telogen) phases; we describe this cycle in our article on the hair growth cycle. When a follicle in the growth phase is put under sudden stress, it can end this phase early, enter the resting phase and let go of its hair. Shock loss is mostly explained by this kind of shift in the cycle; the difference is that it happens in and around the recipient area during the same period.

In transplanted hair

Grafts (small pieces of tissue carrying one or more hairs) are cut off from the blood supply from the moment they are removed until they are placed in the channels; in their new location, their blood supply is not restored straight away but builds up again over time. Most of the transplanted follicles let go of their hair in the weeks that follow; this is thought to be how they respond to that stress: by entering the resting phase.

In your own surrounding hair

If you have hair of your own in the recipient area, the channels are opened between these hairs. The strain on the tissue while the channels are being opened, the swelling and healing response that follow, and temporary changes in blood flow in the area are thought to be factors that may contribute to these follicles being affected as well. Some of these follicles may also enter the resting phase early and let go of their hair. Less often, similar shedding can also occur in the hair that remains in the donor area, where the grafts are taken from.

This is likened to telogen effluvium, which affects the whole head, except that here it is confined to the recipient area. However, when the shedding starts and how long it lasts can vary from person to person. The details of the process, and how much each factor contributes, are not fully known; most likely, several factors are at work together.

When does it start, and when does it pass?

The shedding often starts in the weeks after the procedure and may continue for a while. When the scabs come off, some short hairs may come away with them; this is a normal part of healing and in most cases does not mean that the graft has been lost.

A follicle that has let go of its hair rests for a while; on the scalp, the resting phase normally lasts a few months. That is why the recipient area is often at its sparsest in the first few months. If the surrounding hair has also fallen out, the area may look even sparser than before the procedure for a while. This can be worrying, but on its own it does not show what the result will be.

Transplanted hair usually starts to grow within a few months, at first as fine, sparse hairs. Healthy hair that fell out temporarily also often grows back on a similar timeline. It takes longer for the hair to thicken and for the result to become clear; this period also varies from person to person. We describe the timeline in detail in our article on when transplanted hair grows.

Is shock loss permanent?

In most cases, no; but this is not the same for every hair. Whether a hair that falls out will grow back depends largely on its condition before it fell out.

Miniaturization (shrinking of the hair root) is when, in genetic hair loss, sensitive follicles shrink from one cycle to the next and produce thinner, shorter hairs; we describe this in our article on male pattern hair loss. Some of these follicles might have stopped working over time anyway, even without a transplant; shock loss may bring this process forward.

In this case, some of your own hair in the recipient area may not grow back, and the difference the transplant makes to that area may look smaller than you expected. We want to be clear about this: we cannot tell you in advance that every hair will grow back after shock loss. A transplant also does not stop the loss of your own hair in areas that were not transplanted; this hair loss may progress over time.

Who is more likely to have shock loss?

Shock loss is reported to be more common in the following situations:

• When you have a lot of your own hair in the recipient area and the grafts are to be placed between these hairs
• When a large share of this hair has already become thin
• When your hair loss is still progressing quickly
• In women, because the transplant is often done between existing hairs

Having one of these does not mean you will have shock loss, and it can happen even if you have none of them. These factors only show that we need to weigh the possibility more carefully when planning.

What do we not know yet?

• Who will have it, and to what extent: In two people who had a transplant with a similar plan, shock loss can follow very different courses, and the reason for this difference is not fully known. We can look at risk factors during the examination; however, it is not possible to predict in advance whether shedding will happen or how much.
• Which thinned hairs will grow back: We cannot reliably predict in advance whether a miniaturized follicle will produce hair again after the stress.
• Can it be fully prevented? A careful technique that avoids damaging the roots of existing hair may help reduce the risk; however, there is no known method that fully prevents shock loss.
• The role of medications: Some doctors believe that taking medications used for hair loss around the time of the procedure may reduce shock loss; the evidence supporting this is limited. Only your doctor can determine, after assessing you, whether such a medication is suitable for you. If you are already taking a medication, mention it during the examination; do not start any medication or supplement on your own, and do not stop a medication you are taking without asking your doctor.
• Supporting procedures: The evidence that procedures such as PRP reduce shock loss or speed up recovery is limited.

How do we approach shock loss during the examination and follow-up?

During the examination, we look not only at the bare areas but also at your own hair remaining in the area to be transplanted. From differences in thickness between hairs, we assess how much of this hair has become thin; examining the scalp with a magnifying device (trichoscopy) can help with this assessment. Before the procedure, we talk openly with you about the possibility of shock loss and the fact that hair that has already thinned may not grow back.

When opening the channels and placing the grafts, we take care not to damage the roots of existing hair. After the procedure, we give you written aftercare instructions; if there is a difference between the general information in this article and your instructions, follow your instructions. We describe the general framework of aftercare on the hair transplant aftercare page.

At follow-up appointments, we review the overall condition of your hair as well as the recipient area. Contact us without waiting for your follow-up appointment if:

• The shedding is spreading beyond the recipient area, is happening in patches, or is not easing even after months have passed
• You have increasing pain, redness, swelling or discharge in the recipient area or the donor area, or you develop a fever

In an emergency, or if you cannot reach us, go to the nearest healthcare facility. If we suspect that the shedding has a cause unrelated to the hair transplant, we recommend that you see a dermatologist for an assessment; we do not diagnose online. Whether you are suitable for a hair transplant is determined during the examination; the healing process and results also vary from person to person.