Sadie's Scalp Notes - Notes on your scalp, not your shampoo.

01 / About the notes

Why most hair advice misses the follicle entirely.

Most scalp content in beauty media is aggressively product-forward. A brand launches a product, marketing budgets flow, and breathless claims are published. Sadie's Scalp Notes was born out of the exact opposite discipline: What does peer-reviewed dermatological research actually demonstrate? What happens at the follicle level past the third month?

I am an independent researcher who spent over a decade deciphering clinical cosmetic patents, gas chromatography assays, and medical trichology texts so I could write with absolute clarity. This publication is where I share deep investigations that defy brief social word counts: slow multi-month product logs, formulation audits, and microscopic observations of the epidermal acid mantle.

There are no salon sponsorships here. No 10-step regimens to purchase. Simply quiet, rigorous notes whenever an insight is genuinely worth keeping.

02 / What you will find

01

Ingredient Honesty

What the formula actually contains - and what that means.

Active concentrations, molecular weight penetration depth, and the enormous gap between marketing hype and true follicular mechanism.

02

Scalp Conditions, Plainly

Dryness, oiliness, micro-inflammation - the spectrum explained.

What is physically happening at the follicle orifice and infundibulum, stripped of salon mystification and sterile medical jargon.

03

Slow Reviews

Evaluated across months, not influencer days.

Human hair follicles turn over on anagen cycles of 2 to 7 years. Meaningful changes take months to manifest; so does the writing here.

04

The Research Stack

Clinical papers, archives, and the occasional rabbit hole.

Annotated clinical trials, dermatology congress abstracts, and historical monographs outside the conventional commercial bubble.

Recent dispatches

VOL. IV · 2026 ARCHIVE

Note 04 · Ingredient Honesty

Zinc pyrithione: what actually makes it work, and when it fails.

An exhaustive look at the biochemical mechanism, the concentration problem in surfactant bases, and why the exact same active reads differently in a clinical suspension versus an everyday supermarket shampoo.

April 2026 · 12 min read

Note 03 · Slow Review

Eight weeks with a copper peptide scalp serum: the honest log.

Week-by-week dermal observations on micro-circulation, follicle density, lipid production, and what actually changed. The sensory texture, the viscosity, and the distinct finding that surprised me at week five.

March 2026 · 16 min read

Note 02 · Scalp Conditions

Seborrheic dermatitis is not standard dandruff: the critical distinction.

The two conditions stem from different yeast interactions, demand completely distinct therapeutic lipid ratios, and respond to divergent surfactants. Conflating them causes prolonged chronic irritation.

February 2026 · 14 min read

Note 01 · Research Stack

Four clinical papers on sebum that altered how I formulate.

Directly annotated citations, study methodology appraisals, and practical deductions for oil-prone scalp types. Three of these studies are open-access and available without paywalls.

January 2026 · 19 min read

The Writer

Researcher · Author

Sadie Vance

Sadie is an independent researcher and essayist dedicated to formulation honesty, scalp ecology, and evidence-based trichology. She examines peer-reviewed biochemical literature, evaluates longitudinal product efficacy, and dissects follicle-level physiology.

Through her newsletter and extended long-form monographs, she empowers readers to truly understand what ingredients touch their scalp - and what the empirical science actually supports.

Occasional Dispatches

No fixed cadence.
Just what's worth knowing.

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Notes on your scalp, not your shampoo.