About this notebook

Nutrient Notebook is a small independent site that reads the evidence behind hair supplements and writes it down plainly. It covers Nutrafol, Viviscal, biotin, saw palmetto and the other ingredients people most often ask about, and it grades each on what published studies show.

Not reviewed by a clinician

The direct answer: nobody on this site is a doctor, dermatologist or pharmacist, and no clinician has reviewed these pages.

Every page is written from published sources: peer-reviewed papers found through PubMed, fact sheets from US government agencies such as the FDA and the NIH, regulator guidance from the FTC, and the sellers' own product pages and labels. We name each source and the date we read it. We do not claim medical review, and if you ever see a page here that suggests otherwise, please tell us so we can fix it. Nothing here is medical advice; a doctor who knows you should make any decision about starting, stopping or combining treatments.

How grades are set

The direct answer: by the design of the best evidence we can find, not by popularity or payout.

Our five grades, from Good to Untested, are defined on the hair growth supplements evidence page. The one scored product review, our Nutrafol review, adds a published 10-point rubric covering trial design, independence, safety candour and price candour, and shows the arithmetic. If a new trial appears, the grade changes; if a price changes, the page changes and the date moves.

What we will not publish

• Before-and-after photos, testimonials or invented results.
• Dosing instructions for any supplement or medicine.
• Coupon codes or "where to buy cheapest" pages for prescription drugs.
• Claims that a supplement cures, guarantees or permanently fixes hair loss.
• Rankings of clinics or named doctors.

How the site is paid

The direct answer: through affiliate commissions on a few supplement brands, disclosed on every page that carries a link.

When you buy through one of our marked links, the seller may pay us a commission. That money never decides a grade, and our affiliate disclosure lists every programme we use and the ones we have refused. The steps we recommend most often, seeing a doctor, asking for a blood test and buying over-the-counter medicines from any pharmacy, earn us nothing.

Corrections

If you find an error, a stale price or a study we missed, write to us through the contact page. We correct the page, update its date and, where the change affects a grade, say so on the page.