Head&shoulders
The Amazon link is an affiliate link. Greenlens may earn a commission; it never changes a rating or ranking.
Raters split
Ingredient safety
A 32-point gap between the two loudest voices.
Cleaner options
See 41 cleaner alternatives
Same category, ranked by ingredient safety, never by affiliate payout.
Lowest 68 · highest 100 · gap 32
Coverage & match quality
4 ratings · 2 of 4 axes
no black box
We don't rate products ourselves. We collect what each public rater already says, put every scale on common ground, and keep the disagreements visible instead of averaging them away.
Collect each rater's own score
Every source keeps its native verdict for this product. We never invent a score for an axis a source didn't measure.
Normalize to 0–100, higher = better
Raters can use different scales and directions: some where a low number means safe, some where a high one does. We map them all onto one 0–100 axis and flip the ones that run backwards so the numbers are finally comparable.
Average per axis, but keep the spread
Scores on the same axis become one representative number (their mean). When raters split by 20+ points we flag it and keep every rater's number. A disagreement is never blended into silence.
Your weights make the overall
The ring is the weighted average of the four pillars using your weights. It's computed fresh every time and never stored, so there's no hidden “objective” default.
worked example · Ingredient safety
Raters split here, so this 79 is a midpoint, not a consensus. The spread stays on the “every rater” list above.
Greenlens Ingredient Scan
Independent · EU regulatory reference
Flagged 4 of 24 ingredients: 2 of concern, 2 regulated allergens.
Starts at 100; 20 other ingredients carried no recognized regulated hazard. Absence of a flag means no regulated hazard was recognized — not proof of safety. This is one lens; see where raters disagree above.
Tune your weights
composite recomputes live
+No rater covers this axis for this product, so its weight can't move the score.
No rater covers this axis for this product, so its weight can't move the score.
Range 49–65
Ingredient safety is lifting your score: Greenlens Ingredient Scan (Independent) scores it 68 while Greenlens Tolerance Screen (Independent) scores it 100.