Clinical study of the bond repair protocol
CLINICAL STUDY
Bond repair protocol
Repaired, stronger and nourished hair
The Bond Repair Protocol was developed to repair hair.
Thanks to a combination of complementary treatments, it acts directly on the hair fibre to restore its structure, improve its strength and restore softness, suppleness and shine to the hair.
Scientifically evaluated effectiveness
The repair protocol has undergone two types of scientific evaluation:
- two ex vivo studies to analyse the effect of the protocol on the hair fibre
- a consumer study to assess perceived effectiveness after use
The protocol studied includes:
- Bond repair shampoo
- Bond repair mask
- Bond repair serum
EVALUATION PROTOCOLS
The method
Ex vivo studies on the hair fibre
Ex vivo studies are carried out on natural human hair strands.
This scientific method makes it possible to precisely observe the condition of the hair fibre and its improvement after using the protocol.
The protocol consists of:
- analyse the initial condition of the hair fibre
- apply the complete routine
- compare the results with untreated hair strands or hair strands treated with a neutral product
Study using SCANNING ELECTRON MICROSCOPY (SEM)
This method is carried out on hair strands, making it possible to visualise the surface of the hair, and is performed in several stages:
- Analyse the initial condition of the hair fibre
- Bleach the hair strands
- Analyse the condition of the hair strands
- Apply the complete protocol
- Observe the effect of the protocol on the surface of the hair
Observations are carried out on 10 hair strands using a scanning electron microscope, enabling precise analysis of the hair surface and the condition of the cuticle. Hair morphology is then assessed by a trained expert according to an evaluation scale.
Colourimetric evaluation
The protocol consists of monitoring changes in the condition of the hair fibre across 3 groups:
- Treated group: bleached hair strands + treated with the tested products (shampoo, mask & conditioner)
- Positive control (CTR+): bleached, untreated hair strands
- Negative control (CTR-): unbleached, untreated hair strands
Measurements are taken at 5 time points: before bleaching (T-1), after bleaching (T0), then after 1, 8 and 16 applications (T1, T8, T16).
An Ellman test (colourimetric method) is carried out to quantify thiol groups (-SH) in hair strands, making it possible to assess the protocol's ability to repair disulphide bonds degraded by bleaching. Ellman's reagent reacts with free thiols to produce a yellow anion measurable by spectrophotometry at 412 nm. The intensity of absorbance is directly proportional to the thiol content.
Two measurements are taken:
1. free thiols naturally present in hair
2. total thiols after complete reduction of disulphide bonds with sodium borohydride (NaBH4 ).
The samples are incubated, neutralised and then analysed to quantify thiols based on the absorbance obtained.
STUDY RESULTS
The results
Studies demonstrate a visible improvement in the quality of the hair fibre:
- the fibre is repaired and strengthened*
- the surface of the hair is smoother*
CONSUMER RESULTS
The damaged appearance of lengths and ends is reduced
Hair appears softer and more supple. It is nourished and stronger.
A usage test was conducted on 44 subjects after 28 days of using the Bond Repair Protocol (Luxéol Bond Repair Shampoo + Mask + Bond Repair Serum), 2 to 3 times a week.
Repaired, nourished and visibly more beautiful hair
97% find their hair revitalised, hydrated and nourished
95% find their hair repaired
95% find that the protocol restores the hair fibre
97% find their hair more beautiful
97% find their split ends less visible
90% notice immediate and long-lasting results
*Ex vivo tests, 10 hair tresses, 16 applications of the Protocol (Shampoo, Mask and Bond Repair Serum):
+64% surface repair, measured by scanning electron microscopy
+46% deep repair, assessed by colourimetry
