When do transplanted hairs take root? Conditions that affect engraftment and timing of completion

Whether transplanted hair "takes root (becomes established in the new location)" cannot be judged by the appearance immediately after surgery or by the temporary shedding of hair. The damage incurred when harvesting the hair, desiccation, storage methods, the density of transplantation, and the post-operative hair growth cycle all affect results. Final evaluation is approximately one year after surgery.[1][2].

What remains if engraftment is successful?

Whether engraftment has succeeded is assessed not by the visible hair shaft (the visible part of the hair) but by whether the transplanted hair follicles (the root structures that produce hair) generate new hair in their new location. The hair shaft may shed temporarily. Therefore, shedding of hair in the early period after surgery alone does not indicate failed engraftment of the hair follicles.[3].

What factors influence the process from harvesting to transplantation?

What matters is the series of steps: harvesting the hair follicles without cutting them, preventing desiccation, storing them under appropriate conditions, and transplanting them without excessive force. Research comparing hair follicle survival using preservation solutions and temperature has been conducted, and the handling of the time spent outside the body is critical.[1].

Does higher density transplantation improve engraftment?

No, simply increasing density does not automatically improve engraftment. The engraftment rate varies depending on surgeon skill, transplant density, hair follicle preparation, and degree of desiccation. Review articles (papers summarizing multiple studies) also explain that a certain number of transplanted grafts do not engraft.[4].

When can results be evaluated?

Hair growth becomes apparent around three to four months post-operatively, and changes become more noticeable around six months.[2]According to guidelines (official directives for physicians), final result evaluation is performed nine to twelve months post-operatively. The approach indicates avoiding premature decisions about additional procedures.[5].

Monitoring progress when concerned

Keep progress photographs under the same lighting and hairstyle. Assess not only the transplanted area but also changes in the original hair. If you notice delayed hair growth, localized redness or pain that persists, or other concerns, avoid adding treatment based on your own judgment—instead have a physician examine you to confirm the hair growth cycle and scalp condition.