There are many properties hair and nails share with the skin. Consequently, there are a number of laboratory tests that are routinely employed to evaluate skin which can be applied to both hair and nails.
Hair Care Treatment Studies/Half Head Tests:
- Thinning hair studies
- Hair shaft diameters
- Anagen/Telogen ratios
- Hair Counting analysis
- Gravimetric hair pull analysis shampoo and conditioner efficacy
- Antidandruff studies
Hair Trichological Count
Hair Count Analysis – allows the determination of the hair growth patterns, before and after treatment programs. A quantity of hair uniquely identified in a specific area of the scalp is used to establish product efficacy via video microscopic procedures.
Gravimetric “Pull” Analysis
A highly developed, manual technique for removing and measuring excess fallout aggregates of hair to establish hair loss reduction patterns.
“Hair Pluck” Technique
Employs specialized forceps to “pluck” hair shafts from the scalp in order to determine the ratio of anagen (active/growth), to catagen (rest) and telogen (passive/falling) phases of the hair growth cycle.
Hair Diameter Measurements
Direct hair diameter measurements are made using optical micrometric techniques.
Regimented Combing
This test employs a standardized combing technique designed to capture hair fallout collectively, which is then separated and counted to establish the number of individual broken, intact and bulbous hairs.
Tensile Strength
The Dia-stron Rheometer is used to measure the force, with respect to the time, necessary to elongate and break a strand of hair as a function of hair strength.
Nails
The properties of nails can be measured by various methods. Hardness can be determined via penetrometer studies. Relative density measurements are performed photo-optically. Even flexability can be determined by an exclusive modification to the Diastron Rheometer designed at Advanced Science Laboratories. Thickness measurements can be established microscopically using an optical micrometer. Additionally, there are other properties of nails, and nail care products such as porosity, brittleness, adhesion, color persistence, durability, general growth and re-application rates that may be determined under specialized Advanced Science Laboratories testing protocols.