Science Library
Hair Strength Testing
Strength language becomes trustworthy when the measurement method stays visible. Hair can feel softer or smoother while remaining structurally weak, which is why ANATOMY treats tensile testing as a method worth explaining in public.
This path follows the proof: single-fiber testing, cross-sectional area, controlled force, breakage under brushing, and the difference between surface feel and mechanical behavior.
What this path explains
Hair strength testing measures how a fiber behaves under controlled force. The 135% claim is meaningful only beside the method, the substrate, and the limits of what the reading can prove.
Start here if the proof claim is what brought you here.
- What Is Tensile Testing for Hair?How fiber strength is measured and why cross-sectional area matters.
- What 135% Stronger Hair MeansA careful reading of the quantified strength claim.
- Why Damaged Hair Breaks When BrushedHow mechanical stress reveals prior structural weakness.
- Heat Damaged Hair: Structure vs Surface FeelWhy heat styling can expose damage that surface feel hides.
Hair porosity science
The porosity cluster in the ANATOMY Science Library covers the structural mechanism that connects bleach damage, cuticle integrity, cortex disulfide loss, and the chemistry that actually rebuilds the fibre:
Mechanism comparisons
Three reaction classes underlie most bond-repair products. Comparison pages contrast them on chemistry, evidence, and application context.
- ANATOMY vs Olaplex Click chemistry vs sulfur-bridge crosslinker. Chemistry, evidence base, and application context.
- ANATOMY vs K18 Click chemistry vs keratin-mimetic peptide. Independent tensile data vs single-step speed.
- Olaplex vs K18 Sulfur-bridge crosslinker vs keratin-mimetic peptide, third-party comparison.
Glossary
Definitional pages. Each entry explains one concept with mechanism-first language.
- Disulfide bondThe S-S covalent bond between two cysteines that gives hair its strength.
- Click chemistryThe 2022 Nobel Prize-winning reaction class.
- Thiol-ene couplingMono-adduct click reaction between a thiol and an alkene.
- Thiol-yne couplingBis-adduct click reaction between a thiol and an alkyne.
- KeratinThe structural protein that forms hair fiber.
- CuticleThe outer scale layer that protects the cortex.
- CortexThe structural core of the hair fiber where reconstruction happens.
- CysteineThe sulfur-bearing amino acid that forms disulfide bonds.
- Cysteic acidThe terminal oxidation product of cysteine in bleach damage.
- Tensile strengthThe force-at-break measurement standard.
Private protocol
Get the molecular reconstruction protocol.
Where damage actually sits, why the complete system comes first, and the private first-order offer — sent by email.