The short answer

A hair transplant works by moving hair follicles from an area of the scalp where hair grows permanently — usually the back and sides of the head — to an area where hair has thinned or been lost. Because those relocated follicles keep growing in their new position, the result is lasting. The procedure is carried out under local anaesthetic while you are awake, takes most of a day, and with modern techniques leaves no visible linear scar. In essence, it does not create new hair; it redistributes the hair you still have to where it is needed most.

The biology behind it

To understand why a transplant works, it helps to know why some hair is lost and some is not. In most pattern hair loss, the follicles at the back and sides of the scalp are genetically resistant to the hormone that causes thinning elsewhere — which is why balding tends to follow a pattern, leaving a horseshoe of hair that persists even in advanced cases.

A transplant takes advantage of this. When those resistant follicles are moved to a thinning area, they keep the characteristics of where they came from — a principle known as donor dominance — and carry on growing much as they did before. This is why transplanted hair is generally permanent, while the untransplanted hair around it may continue to thin.

Many of the terms used on this page — follicular unit, graft, donor area, and others — are explained in more detail in our hair transplant glossary, which may be a useful companion if any of the language here is unfamiliar.

The procedure, step by step

Although details vary between clinics and techniques, a hair transplant generally follows the same sequence over the course of a day.

It begins with planning and design. The surgeon assesses the scalp, agrees the shape and position of the new hairline or the areas to be filled, and marks them out. This stage matters more than its short duration suggests, because the design largely determines how natural the result will look.

Next comes preparation and anaesthetic. The donor area is trimmed, and local anaesthetic is applied to numb both the donor and recipient areas — a step that usually takes around thirty to sixty minutes and is, for most people, the only genuinely uncomfortable part of the day.

Then extraction. In the most common method, follicular unit excision (FUE), individual follicular units are removed one by one from the donor area using a small punch tool, leaving tiny marks that heal without a visible linear scar. Extraction typically takes between two and four hours, depending on how many grafts are needed. The extracted grafts are kept in a preservation solution while they wait to be implanted.

After extraction, the recipient area is prepared and the grafts are implanted. The surgeon creates small sites in the thinning area at the correct angle and direction, and the grafts are placed into them — either into pre-made sites, or, in the DHI variation, created and filled in a single motion with a specialised pen. The differences between the main techniques are covered separately, but the underlying goal is the same: to place each graft so that it grows in a natural direction and pattern.

A standard session runs to somewhere between six and eight hours in total, with most cases of two to three thousand grafts completed in a single day. Larger cases may run longer or be split across two days to protect the grafts.

What the day feels like

The clinical steps describe what happens, but not what it is like to sit through — which is something clinics do not always explain well.

For most people, the experience is long rather than painful. Once the anaesthetic has taken effect, the extraction and implantation themselves are generally not painful, though they are lengthy: you are awake throughout, usually lying down or reclining, and many people read, watch something, listen to music, or doze through parts of it. There are normally breaks for food and rest.

The part most people find genuinely uncomfortable is the anaesthetic injections at the start, before the numbing takes hold. It is a real discomfort but a brief one, and many clinics use methods to reduce it. Beyond that, most patients are surprised by how tolerable the day is — the more common complaint afterwards is tiredness and stiffness from sitting still for hours, rather than pain.

What happens after

In the days after the procedure, small scabs form around each transplanted graft and the scalp may be swollen and tender; the scabs typically fall away within one to two weeks. The transplanted hairs themselves usually shed a few weeks later — an expected and much-misunderstood stage — before the follicles begin producing new growth after a few months. The final result generally takes twelve to eighteen months to mature fully.

This is only a brief outline; what recovery involves, stage by stage, is covered in our guide to hair transplant recovery.

What to do next

Understanding how a hair transplant works is a good first step. The next — and more personal — question is whether one would work well for you: whether your hair loss is the type a transplant treats, whether your donor supply is sufficient, and whether the timing is right. That depends on your particular situation.

That is what a FOLiQA assessment is designed to help with. You complete a detailed intake about your hair loss and your goals, and we give you an honest, independent verdict on your candidacy — yes, no, or not yet — with the reasoning explained. We are paid by you, not by clinics, so the assessment's only job is to get your decision right.

The cost is €59. Set against a procedure that runs into the thousands and cannot be undone, understanding whether it is right for you — before you commit — is worth a great deal.

This guide is general information, not medical advice. Read our full disclaimer.