New hair transplant review challenges fixed donor limits

Dr. Umar and colleagues outline how individualized assessment may reveal additional graft options while identifying areas to avoid

MANHATTAN BEACH, Calif., Oct. 22, 2026 /PRNewswire/ -- Dr. U Hair and Skin Clinic in the Los Angeles area reports that a new clinical review led by Sanusi Umar, MD, challenges reliance on fixed maps to define hair transplant donor areas. The open-access paper, "Redefining the Safe Donor Area in Follicular Unit Excision: Toward Dynamic, Patient-Specific Zones," was published Oct. 16 in the Journal of Cosmetic Dermatology.

Read Dr. Umar's illustrated companion article for clinical photographs and a plain-language explanation of how the shave test helps guide individualized donor assessment.

Traditional donor maps identify hair at the back and sides of the scalp that is relatively resistant to pattern hair loss. These maps remain useful starting points, but may exclude usable hair in some patients or include thinning regions in others.

"A donor map should be a starting point, followed by examination of the individual patient," said Dr. Umar, a board-certified dermatologist and lead author. "That assessment may reveal additional graft options, including finer hair for a softer hairline, or show why harvesting boundaries need to be smaller."

Evidence reviewed and key findings

The narrative review, authored by Dr. Umar, Aditya K. Gupta, Vasiliki Economopoulos and Mesbah Talukder, examines donor variability and tools for refining boundaries. It revisits Dr. Umar's 2015 observational series of 128 men treated with nape and periauricular hair for hairlines and temples.

Key points included:

• The shave test examines changes in hair thickness and density after close clipping. A gradual transition toward the nape and around the ears may support selective harvesting of additional peripheral hair.
• An abrupt decline in thickness or density can reveal unsuitable hair and indicate that donor boundaries should be narrowed. Magnified scalp examination, age, family history and hair-loss progression help guide selection.
• Donor grading and ratio-based methods provide additional tools for refining boundaries. When peripheral scalp hair is unsuitable, clinicians may consider conventional scalp donor hair or separately assess beard and body hair as alternative sources where clinically appropriate.
• Thirty-three patients from the earlier series completed longer-term questionnaires at an average of 4.6 years. The review separately presents one patient's 14-year follow-up showing retained transplanted hairline coverage despite further native frontal hair recession.

Why the findings matter

Follicular unit excision, or FUE, enables individual hair units to be harvested across broad scalp areas. As larger sessions place greater demands on donor resources, individualized assessment can help identify additional usable hair while protecting unsuitable zones.

The framework starts with a conservative core donor area, then refines its borders using scalp findings. Selected peripheral regions may offer additional grafts, while donor thinning can require a smaller harvestable area. Decisions also consider remaining donor coverage and future hair loss.

The authors call for larger prospective studies with standardized long-term follow-up. A favorable shave test does not guarantee lifelong graft permanence or establish a universal additional graft allowance. Read the full open-access review at https://doi.org/10.1111/jocd.71250.

About Dr Sanusi Umar

Sanusi Umar, MD, is a board-certified dermatologist, founder of Dr. U Hair and Skin Clinic, and a UCLA and Harbor-UCLA clinical instructor specializing in complex hair loss, baldness and scarring alopecias.

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