Donor Area

The donor area is the horseshoe of scalp at the back and sides of the head where hair is genetically resistant to DHT. It is the only hair used in a transplant.

Where you'll meet it

In every consultation, usually as a number. How many grafts your donor area will yield is the most important fact about your own head.

Why only this hair

Follicles here are largely insensitive to DHT, and they keep that insensitivity when they are moved. Transplanted hair behaves like where it came from, not where it ends up.

The limits

Somewhere around 6,000 to 8,000 grafts is a typical lifetime ceiling, and many people have less. Surgeons work to a maximum harvest density rather than a maximum number, thinning the area evenly so it still reads as full.

Over-harvesting produces a visibly thin or moth-eaten donor area, which is harder to disguise than the loss it was treating and cannot be reversed. Body hair extends the supply at lower reliability; nothing restores it.

How it is measured

With a densitometer or magnified camera, counting follicular units per square centimetre at several points. A lifetime estimate given without measurement is a guess, and usually an optimistic one.

Ask for the number and write it down. Every surgeon you ever see will want it.

← Back to the Glossary