This week’s issue is brought to you by Codex Labs
Welcome back, DERM Community!
Last week we sat with the pharmaceutical representative, one of the more useful and more misunderstood relationships in day-to-day practice, and worked through how to run a 20-minute visit as a clinical working session instead of a sales call.
This week we're starting something new.
Over the next several issues we're running a series on the everyday patient complaints that sound trivial, get waved off, and turn out to have real mechanisms underneath them.
The kind of thing a patient mentions at the end of a visit, almost apologetically, that you can answer in thirty seconds if you know the science and lose ten minutes to if you don't…
We're opening with the one nearly every clinician has heard some version of: "My shampoo used to work great, but now my hair feels dull and oily again."
The patient's assumption is almost always the same: their hair "got used to it."
Here is what's actually happening:
Rotate shampoos every few weeks so your scalp doesn't adapt to one formula.
Scrub your scalp, not just your hair, for 60-90 seconds per wash.
Rinse with cool water at the end to seal the hair cuticle.
Clean your hairbrush weekly or you're putting buildup right back in.
More lather doesn't mean cleaner - sulfate-free shampoos work just as well with less foam.
Track your cycle or hormone shifts if your scalp changes suddenly with no other explanation, hormones are often the invisible culprit.
Give your scalp 2-4 weeks to adjust when switching routines, most people quit too early and never see results.
Indoor environments matter too - heated or air-conditioned rooms dry out your scalp just like outdoor weather does.
Keep two shampoos on hand year-round - one gentle, one stronger, so you can adjust without starting from scratch.
Moving cities is a hair reset - new water, humidity, and pollution all interact, so expect a transition period and don't blame your products right away.
Don't self-diagnose scalp conditions - seborrheic dermatitis, psoriasis, and contact dermatitis can look nearly identical, and treating the wrong one can make things worse.
Fragrance is the most common contact allergen in hair products - if your scalp is reactive, go fragrance-free before trying anything else.
Medicated shampoos stop working if overused - once symptoms are controlled, dropping to once a week maintains results without resistance buildup.
Stress is a major flare trigger for both seborrheic dermatitis and psoriasis, managing it is part of the treatment, not just a bonus.
Hair loss from scalp conditions is often reversible if caught early, but delays in treatment make recovery slower and less complete.
Practical Reset
The instinct when a shampoo "stops working" is to abandon it and buy something new. That's usually the wrong move, and it resets the same cycle a few months later.
The better approach is structural.
Rotate, don't abandon. Alternate a gentle daily shampoo with a clarifying shampoo roughly once a week to clear buildup before it accumulates.
In hard-water areas, work in a chelating formula occasionally to lift mineral deposits the everyday shampoo can't.
Match wash frequency to the scalp in front of you, not to habit, and expect that frequency to shift with the season.
Counsel against constant switching. Changing shampoos too often gives the scalp nothing stable to settle into and tends to create the exact instability the patient is complaining about.
And anchor the whole conversation on the one line worth repeating: when a shampoo seems to stop working, the product almost never lost its efficacy. Biology and environment reshuffled the equation around it.
Interested in reaching our 8,000+ subscribers?
Click here to learn more!
We’ve Put Together a Free Guide Just for You!
My Shampoo Stopped Working: A Quick Reference
This guide turns that complaint into a fast, evidence-based workup. You'll get a rapid diagnostic table that maps the five questions to ask against the most likely cause and the immediate action for each, from product buildup and hard water to sebum shifts, overwashing rebound, and underlying scalp conditions. From there it lays out the Strategic Rotation Protocol (why random switching fails and what to recommend instead), solutions broken down by cause with real product examples, and a scalp-conditions table covering seborrheic dermatitis, psoriasis, and folliculitis, with clear referral criteria. It closes with the clinical pearls worth keeping in your back pocket.
830.05 KB • PDF File
Some Jobs We Think You’re Gonna Love:
Find them here!
Want to Go Deeper?
Take one of our modules
Whether you’re a clinician, student, or educator, our eczema module breaks down atopic dermatitis, contact dermatitis, dyshidrotic eczema, nummular eczema, and more.
Book Recommendation of the Week
“Skin Microbiome Handbook: From Basic Research to Product Development” by Nava Dayan
The book provides a comprehensive detailed summary of current status on skin microbiome research in health and disease as well as key regulatory and legal aspects.
Inspiration of the Week
“Dwell on the beauty of life. Watch the stars, and see yourself running with them.”
-Marco Aurelius
👋🏻 See you next Thursday, DERM community!
Thanks for joining us on Beneath the Surface.
Over the coming weeks we're going past the small complaints and into the bigger ground: the diseases that quietly worry all of us, the ones we see often enough to feel routine and rarely get to sit with properly, alongside the new and frankly fascinating trends reshaping how we understand the skin as an organ and what it tells us about the rest of the body.
Some of it will be reassuring. Some of it will challenge what we were taught.
We built Beneath the Surface to do exactly this: take the things that look simple on the surface and show you what's actually moving underneath.
Thank you for being here with us!
— The Derm for Primary Care Team
