Published 12 September 2026. This replaces an earlier article that claimed our herbs treat the scalp while they colour. It is written for anyone who wants to know what herbal scalp care actually rests on — and it sorts every claim into one of three bins, because most writing on the subject does not.
The three bins
- Tradition. What Ayurvedic practice has said and done, sometimes for a very long time. A real record of use. Not a record of results, because nobody was counting.
- Measured. What a study found. We say what was studied, on whom, and what the study did not test — because the distance between a study and a pouch of powder is usually the whole story.
- Plausible, untested. What the chemistry makes reasonable to suspect, and what nobody has checked. This is the largest bin. It is also the one most often relabelled as the second.
Every claim below carries one of those labels. If you take nothing else from this article, take the habit of asking which bin a claim belongs in.
First, what the scalp is
None of this is about herbs yet. It is about the surface the herbs land on, and all of it is measured.
The scalp is skin. Its outer layer, the stratum corneum, is a barrier built to keep water in and most things out. Small, oil-soluble molecules cross it more readily than large or water-loving ones. Two things raise how much gets through: hydration, because wet skin is more permeable, and occlusion, because covering the skin traps moisture and warmth. A wet paste under a shower cap for an hour or two does both. That is why our How It Works page says that yes, some of what is in the paste probably reaches your scalp. It is also why “it is natural” is not a reason to skip a patch test.
The scalp is acidic. Its surface sits around pH 4.5 to 5.5. That acidity is part of the barrier, and it keeps the resident microbes in check. Products far above it — true soaps, most conventional dyes — disturb it for a while; the skin restores it, but not instantly.
The scalp has residents. A yeast called Malassezia lives on everyone’s scalp and feeds on skin oil. Dandruff is, in most people, the skin’s reaction to it. Anything that changes oil, moisture or acidity changes the conditions it lives in — which is the honest mechanism behind most “antidandruff” claims, herbal or otherwise.
The follicle runs on its own clock. A scalp hair grows for two to six years, rests, sheds, and starts again. Anything that claims to affect growth has to act on that cycle, and the cycle is slow. It is the reason a real growth study takes months, and the reason most herbal growth claims have never been tested on a human at all.
What we have measured ourselves
We own a pH meter, and we have used it on every wash and treatment powder we sell. This is the one place where our own numbers touch the scalp directly.
| Mixed with water | pH | Against the scalp’s 4.5–5.5 |
|---|---|---|
| Shikakai | 2.1–3.0 | Well below |
| Hair Treatment Powder (amla, reetha, shikakai) | 3.2–3.5 | Below |
| Amla | 3.46 | Below |
| Reetha | 4.5–4.9 | Inside the range |
| Plain tap water | 6.65 | Above |
| A true soap bar | 9.35 | Far above |
What this tells you is narrow and real: none of our washes push the scalp toward alkaline, and one of them, reetha, sits inside the scalp’s own range. What it does not tell you is whether that produces any benefit you would notice. Nobody has measured a scalp before and after months of reetha. We have measured the paste, and that is all we are claiming.
The herbs, one at a time
Bhringraj (Eclipta prostrata, syn. E. alba) — in 22 of our 24 shades
Tradition. Kesharaja, king of hair. The scalp herb of Ayurveda, used against hair loss and early greying for as long as the practice has been written down.
Measured. One animal study is the source of nearly every “bhringraj grows hair” claim online. Roy, Thakur and Dixit (2008) applied extracts to shaved rat skin daily, alongside minoxidil, and saw hair return in about half the usual time with more follicles in the growing phase. The finding is real. The conditions were: petroleum-ether and ethanol extracts (solvents that pull out what water largely leaves behind), carried in an oily cream, on shaved skin, every day, in rats. A mouse study with a methanol extract reached a similar conclusion. No human trial exists, and none of milled leaf in water.
Plausible, untested. The leaf contains wedelolactone and related coumestans, some of which show anti-inflammatory activity in cell studies. Given hydration and occlusion, some fraction likely reaches the skin. How much, from a water paste, once a month — nobody has measured, and the solvent-extract studies cannot tell you.
Brahmi (Bacopa monnieri) — in 11 of our 24 shades
Tradition. First a herb for the mind. Its hair use is real but secondary, and comes largely from being oiled together with bhringraj. A different plant, Centella asiatica, is also called brahmi in some regions; ours is Bacopa, and the two are unrelated.
Measured. The bacosides have been studied for cognition, by mouth. Applied to the scalp, we have found nothing. Claims that brahmi feeds the scalp with vitamin C and zinc do not survive a look at what a dried leaf powder actually contains, and we have withdrawn ours.
Plausible, untested. Bacoside A is a saponin mixture; saponins on skin are mildly cleansing and can be mildly irritating. Beyond that we have nothing to offer, and we do not claim a scalp effect for brahmi at all.
Neem (Azadirachta indica) — sold on its own; not in any shade
Tradition. The village pharmacy of India. For the scalp: itch, flaking, and the general category of “things living on the skin”.
Measured. Neem leaf extracts show antimicrobial and antifungal activity in laboratory glassware, including against yeasts. That is an in vitro result — a dish, not a scalp — and the famous neem compound, azadirachtin, is in the seed, not the leaf we mill. What the leaf carries is nimbolide and related limonoids. No controlled trial of neem leaf on the human scalp that we can find.
Plausible, untested. If a leaf paste changes the oil and moisture on the scalp surface for an hour, it changes the conditions Malassezia lives in. That is a mechanism, not a result. Whether it moves a dandruff score, nobody has counted.
Amla (Phyllanthus emblica) — in 23 of our 24 shades
Tradition. In every Ayurvedic hair oil, for the scalp and the strand both.
Measured. Our own meter: pH 3.46, and it holds when diluted. Amla is what keeps our pastes acidic, and acid is on the same side as the scalp’s own surface. That is a measured fact about the paste. What is not measured is any effect of that acidity on the scalp over months of use.
Plausible, untested. An acidic paste does not disturb the acid mantle the way an alkaline one does. Reasonable to expect, never counted.
Reetha and shikakai (Sapindus mukorossi, Acacia concinna) — the washes
Tradition. The soap of the subcontinent before there was soap. Shikakai is Tamil for “fruit for the hair”.
Measured. Both clean through saponins, which we can show you by pH and by the thin, short-lived foam they make. Shikakai is our most acidic powder; reetha is the one that sits inside the scalp’s own range. We have compared them side by side on the shikakai page.
Plausible, untested. A cleanser that does not push the scalp alkaline should leave the barrier less disturbed than one that does. We think that is right. We have not measured a scalp to prove it. And saponins sting: keep both out of your eyes.
Henna and indigo — the pigments
These are not scalp herbs, but they sit on the scalp for an hour, so they belong here. Measured: henna allergy is rare compared with PPD allergy, which is why PPD-based “black henna” is the thing to avoid. Measured, and important: henna and its relatives are a concern for anyone with G6PD deficiency, and we say so on every product page. Tradition: henna is cooling and indigo is drying, in the Ayurvedic sense. Untested: anything beyond that.
What is actually documented about your scalp and a plant colour
Read back over the herbs and notice the pattern. The tradition is long. The animal data is thin and far from the pouch. The human data is almost nothing. That is the honest state of herbal scalp care in 2026, and no brand is in a different position, whatever its copy says.
So where is the benefit? It is in what a plant colour leaves out, and that part is not tradition and not inference. It is on the label, and it is audited.
- No PPD — the most common cause of hair-dye allergy, and present in most permanent colour including much of what is sold as natural.
- No ammonia and no peroxide — nothing on the scalp for that hour that lifts the skin’s pH or oxidises it.
- Twelve plant powders and nothing else, certified by a body that reads the formula rather than the marketing.
Subtracting the irritants is documented. Adding a benefit is not. We would rather you buy on the first than on the second, and we would rather say that plainly than borrow a rat study and call it a promise.
Plants are not inert
Bhringraj is in the daisy family; people sensitive to ragweed or chrysanthemum occasionally react to it. Saponins sting the eyes. Henna is a G6PD concern. Patch test on the inner forearm 48 hours before a full application — the absence of anything synthetic does not change that rule.
What it would take to say more
A real answer needs milled herb, in water, at our ratio and frequency, on human scalps, for months, with a comparison group, counting something a dermatologist would count: shed hairs, follicle density, a dandruff score, irritation. That study has not been done for any herb on this page. If it is, the result goes here whichever way it lands.
Until then: the shade counts are facts, the pH readings are facts, the tradition is a fact, the rat study is a fact with four caveats, and the rest is a plausible idea we are not going to sell you as a finding.
Reference
Roy RK, Thakur M, Dixit VK. Hair growth promoting activity of Eclipta alba in male albino rats. Arch Dermatol Res. 2008;300(7):357–364. doi:10.1007/s00403-008-0860-3 · PMID 18478241. Petroleum ether and ethanol extracts in a water-in-oil cream, applied daily to shaved rat skin, against a 2% minoxidil control.
pH readings are our own, on a handheld meter calibrated against standard buffers, at room temperature; batches vary and we publish the range. Radico Colour Me Organic and our single-herb powders are cosmetic products for external use on hair. They are not intended to diagnose, treat, cure or prevent any condition of the scalp.