Your hair has a three-bond integrity score.
A personalized estimate of the three bond types in your hair — and how to rebuild what is missing.
Take the assessment →What is a three-bond integrity score?
Your three-bond integrity score is a personalized estimate of the structural health of your hair across the three bond types every strand contains — disulfide, hydrogen, and ionic. The score is returned at the end of the 90-second StrandSense assessment, alongside your hair type, porosity, and a regimen built for your result.
Each bond receives its own integrity score on a 0–100 scale, with a corresponding level — Strong (75–100), Moderate (50–74), or Depleted (0–49). The three scores together give you the most useful single-page summary of your hair's structural state you will find anywhere.
Above is what a sample scorecard looks like. Most hair has uneven integrity across the three bonds — that is exactly the point of measuring all three. A regimen built for disulfide repair alone will not address the hydrogen and ionic bonds your scorecard shows are depleted.
This is an estimate, not a laboratory measurement.
A 90-second assessment cannot literally measure the tensile strength of your hair. What StrandSense does is calculate your bond loss risk across the three bond types using inputs you provide — your hair type, history, environment, and routine.
The same way a doctor's cardiovascular risk assessment estimates your heart health from your inputs without literally measuring every artery, StrandSense estimates bond integrity from the inputs that cosmetic chemistry has established as the strongest predictors of bond loss.
It is an estimate. It is also the most accurate one you can get without a trichology lab — and the only one designed to inform a regimen built around all three bond types.
The three bonds, scored.
Each of the three bond types is broken by a different set of forces. The integrity score for each is calculated from a different cluster of inputs.
Disulfide.
Covalent bonds formed between cysteine amino acids. The structural backbone of your hair. The fewest in number but the strongest individually.
Hydrogen.
Weaker than disulfide bonds, but ten times more numerous. Responsible for daily shape, definition, and movement. Break and re-form constantly.
Ionic.
Bonds between charged amino acid groups. Sensitive to one variable above all others — pH. Determine how flat the cuticle lies.
What StrandSense considers.
The assessment captures information across four categories. Each input is weighted differently for each of the three bond scores. Below is the input set in its entirety — full transparency about what feeds the calculation.
Hair characteristics
Damage history
Daily routine
Environmental factors
Self-observed signals
Each input contributes a weighted value to one or more of the three bond scores. The algorithm is calibrated against the bond-loss patterns observed in our clinical trial — which tested across every hair texture, with priority on Type 3 and Type 4 hair.
Tracking improvement over time.
Your first scorecard is the baseline. Every assessment you take afterward is compared against it. You see exactly how your three-bond integrity is shifting as your regimen does its work.
After 12 weeks on a NUELE regimen built for your scorecard, the typical improvement curve looks like the one above — disulfide and hydrogen integrity climbing significantly, ionic integrity steadier and more dependent on continued use of pH-balanced shampoo. Your specific results will depend on your starting scorecard and how consistently you use the recommended regimen.
Your account dashboard shows your scorecard history in one place. Every retake adds a new column to the chart. Over a year, the trend lines tell the story your hair has been writing the whole time.
When to retake the assessment.
The retake is the most important part of the StrandSense relationship. Your first scorecard tells you where you are. The retake tells you where you are going.
Take your first assessment
Establish your baseline. Receive your scorecard and the recommended regimen for your three bond integrity scores. Begin the regimen consistently.
Your first retake
This is the primary retake moment. Twelve weeks matches the clinical-trial duration — the timeframe over which bond rebuild becomes measurable. Most customers see significant improvement in disulfide and hydrogen integrity. We will send you a reminder when the date arrives.
Standing quarterly cadence
Once you have a baseline and a 12-week check-in, the rhythm becomes part of how you relate to your hair. Quarterly retakes let you see seasonal patterns and continue to refine your regimen as your hair evolves.
After any major hair event
Retake the assessment after color, chemical processing, a big chop, transition, pregnancy, or a climate change. These are the moments your bond integrity profile shifts most dramatically — and your regimen often needs to shift with it.
Common questions.
How accurate is my three-bond score?
Your score is a predictive estimate, not a laboratory measurement. It is calibrated against bond-loss patterns observed in our clinical trial and the published cosmetic chemistry of hair bond damage. For most people, it is significantly more accurate than any other haircare diagnostic available without lab access. It is most accurate when you answer the assessment honestly — including signals about damage history and daily routine that you might minimize elsewhere.
Why did my score change?
Three reasons. First, the inputs changed — if your routine, environment, or damage history has shifted, your bond integrity score reflects that. Second, the regimen is working — consistent use of bond-repair products genuinely improves the underlying integrity of your hair. Third, your self-observed signals (breakage, frizz, definition) have shifted, which the algorithm captures.
What if my score does not improve?
The most common reason is regimen inconsistency — using the Hair Mask once a month instead of weekly, or skipping the Hair Serum on busy days. The second most common reason is continued exposure to a damage source that is not addressed in the regimen — for example, heat styling at high temperatures, or hard water at home. If you have used your regimen consistently for 12 weeks and your scores have not improved, reach out — we will help you investigate.
Do I need a NUELE account to track over time?
No. You can take the assessment anonymously every time. However, if you create a free NUELE account, your scorecard history is saved automatically, and you can see your bond integrity changes side-by-side without needing to remember your past scores. The account also unlocks the 12-week reminder email and the progress dashboard.
Is there a perfect score?
No hair has 100 across all three bonds. Even healthy hair is constantly losing and reforming bonds — that is normal biology. The goal of the regimen is not perfection but the highest sustained integrity your hair can carry. Most NUELE customers achieve and maintain a 75-plus average across all three bonds after a year of consistent use.
Take the StrandSense assessment.
Free. 90 seconds. Your three-bond integrity score, your hair type, and the regimen built for what your scorecard returns.
Take the assessment →