Methodology for the Predicted Selection of Hair Extension Technology Depending on the Structure of Natural Hair and the Desired Aesthetic Result

The contemporary hair extension market has developed faster than the methodological standards that should guide professional choice. In practice, extension technology is still selected too often based on trend visibility, price, or the client’s immediate aesthetic request, while the structural compatibility of natural hair is evaluated inconsistently. This creates a clinically and cosmetologically relevant problem, because the same desired result may be achieved by methods that differ greatly in traction profile, load distribution, thermal exposure, maintenance intensity, reversibility, and risk of shaft weakening. This article develops a literature-based methodology for the selection of hair extension technology based on the structure of natural hair and the desired aesthetic result. The study synthesizes twenty English-language scientific sources, including empirical studies, reviews, case reports, and technical investigations of hair fiber properties. A secondary analytical layer compares ten empirical publications (identified in Section 2.1) to isolate recurring variables usable in professional consultation. On that basis, an authorial methodology is proposed. It integrates five diagnostic blocks: fiber thickness, density, curl pattern, cumulative damage, and scalp tolerance, and aligns them with four groups of aesthetic aims: length increase, volume increase, combined transformation, and localized correction. The article argues that the safest and most convincing visual result is achieved not by the most technically impressive extension system, but by the method whose mechanical behavior matches the carrying capacity of natural hair and the realistic aesthetic objective.