Part 1
The Science of Scalp Health
pH, the microbiome and the acid mantle — why most conventional shampoos work against your scalp.
The acid mantle
Your scalp surface sits at a pH of 4.5–5.5, slightly acidic. This thin protective film guards against bacteria, fungi and moisture loss. Alkaline shampoos (pH 6–9) disrupt it with every wash.
The scalp microbiome
Like your gut, your scalp hosts a whole ecosystem of bacteria and fungi. When harsh cleansers, the wrong pH or over-washing upset that balance, opportunistic organisms such as Malassezia yeast can overgrow — a common driver of flaking and seborrheic dermatitis.
Sebum is a friend, not an enemy
Sebum is your scalp's own moisturizer and barrier. Conventional shampoos strip it aggressively, so the scalp produces more. Gentle alternatives work with sebum production rather than against it.
The pH problem
A landmark study (Gavazzoni Dias et al., Int J Trichology 2014, PMID: 25210332) found that 62% of 123 commercial shampoos had a pH above 5.5 — too alkaline for the scalp. Rye flour (pH 5.0–5.5), oat flour (pH 5.5–6.0) and mineral-buffered rhassoul clay all sit far closer to what the scalp prefers.
Not medical advice
This content is for general educational purposes only and is not medical advice. It does not diagnose, treat, or cure any condition and does not create a doctor-patient relationship. For any skin or scalp concern, please consult a dermatologist or physician.
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