Donor area
The band of occipital and temporal scalp whose follicles are genetically resistant to androgenetic hair loss, making it the source of transplantable grafts.
The donor area is the band of scalp across the back and sides of the head — occipital and temporal — whose follicles are genetically resistant to androgenetic hair loss. Transplantation works because of a principle described early in the field’s literature as donor dominance: a follicle keeps the behaviour of the place it came from, so resistant hair moved to a balding zone keeps growing.
The area’s defining property is that it is finite and non-renewable. Every extracted graft is spent forever, and hair loss is progressive: the crown that looks stable at thirty may need coverage at forty-five. Donor planning is therefore lifetime arithmetic — how much can be taken now, at what visual thinning cost, while preserving reserves for sessions a younger patient cannot yet know they will want.
Not all of the band is equally safe. The mid-portion — the safe donor zone — is least likely to miniaturise with age; harvesting near its upper and lower margins risks transplanting hair that will later thin along with the native hair around it. Reading those boundaries on an individual patient, rather than applying a template, is part of surgical judgement, informed by family history and trichoscopic assessment.
Donor management is also where ethics become visible. Overharvesting — extraction so dense the donor looks moth-eaten — is permanent, and it is the signature of volume-driven operations. A surgeon who explains your donor budget, extraction distribution and what is being saved for later is planning a decades-long result, not a single invoice.
Assessment is multi-dimensional: density per square centimetre, hair calibre and curl, follicular-unit composition, and — for strip candidates — scalp laxity all shape what the donor can realistically fund. When scalp reserves are thin, beard and body hair are used in some plans as supplementary sources with different calibre and growth characteristics; they extend the arithmetic but obey the same rule. Nothing about the donor is renewable, so every plan is ultimately an allocation decision.
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