How we test and rank products
Every product reviewed on this site has been used by a working hairstylist on multiple clients over an extended period — not tested in a single review session, not evaluated from a product sample on an editor’s desk. This is the single most important thing separating this site from the “best leave-in” listicles that dominate search results.
Below is exactly how the testing, rating, and ranking work.
Who does the reviewing
Right now, every review on this site is by Barb Thompson — a working hairstylist with over twenty years behind the chair, an R+Co global cutting educator credential, and editorial credits in Vogue, Harper’s Bazaar, InStyle, Marie Claire, and Cosmopolitan. She works in salons in Northern California and Silver Lake, LA.
Read her full bio.
As we add reviewers, every new one will be named, photographed, and credentialed on an individual bio page. No anonymous “our editors” bylines.
How the testing works
For each product category we cover:
- The reviewer tests the product on multiple clients with different hair types (fine, medium, thick, curly, coily, color-treated, damaged) through repeated real-world salon use. For the current leave-in conditioner review, Barb ranked ten products she has used on clients and in her own kit.
- Products are used in real salon conditions — wet hair, dry hair, after cutting, before blowouts, on heat-styled hair, on air-dried hair. Each product is evaluated for how it actually performs in use, not how it looks on a product-shot.
- Results are tracked across environmental conditions the reviewer can actually test: humidity, heat styling at various temperatures, multiple wash cycles, color retention, long-term buildup.
This is chair-tested, client-validated product review. It’s the same process a stylist uses when deciding what goes in their own kit.
Our rating system
Each product receives an overall rating on a 1–10 scale. This is the reviewer’s single-number verdict — how likely they are to reach for this product from their kit, weighted across everything that matters for the product category.
Most reviews also include dimensional ratings specific to the category. For leave-in conditioners, those are:
- Heat protection — how well the product shields hair from blow-drying and flat-ironing
- Moisture — how effectively the product hydrates without weighing hair down
- Shine — the reflective quality the product imparts
- Versatility — whether the product works on wet and dry hair, across hair types
- Scent — how pleasant the fragrance is and how long it lingers
Dimensional ratings let you weigh the product by what matters to you. A 9/10 overall with a 6/10 on shine tells you something different than a 9/10 overall with a 10/10 on shine.
What “clean” means on this site
We use the word “clean” on this site with specific criteria, not as marketing language. For a product to be called clean in our reviews:
- No sulfates (SLS, SLES, ALS)
- No silicones (dimethicone and its variants)
- No parabens
We acknowledge that “clean” has no FDA definition and that the term can be misleading in the beauty industry broadly. We use it here only as shorthand for this specific ingredient exclusion list, which most readers searching for “clean haircare” are actually asking about.
If a product is clean by this definition, we say so. If it isn’t, we don’t pretend otherwise — and it can still be ranked highly. Performance is the primary filter on this site. Clean is a secondary attribute we report so you can make your own call.
Conflict disclosure
Barb Thompson is a paid R+Co global cutting educator. R+Co products that appear in her reviews are flagged with this disclosure on each review page. Barb has rated R+Co products fairly — in her most recent review, R+Co products scored 8/10, placing them in her “recommended” tier but not at the top of her list.
We believe disclosing conflicts directly and letting readers weigh them is more honest than pretending they don’t exist.
Update cadence
Reviews are revisited quarterly. When a reviewer re-tests a product and finds their rating has changed (either up or down), the review is updated and the update is dated. We don’t bump publication dates without substantive updates. If a review says “updated April 2026,” something actually changed in April 2026.
Questions about our methodology?
Email hello@hairstylistapproved.com. We’re happy to clarify how any specific call on this site was made.