Ayurvedic hair care · Single herb
Shikakai
Acacia concinna — shikai, fruit for the hair
It washes like reetha. It leaves the hair different.
Radico makes two herbs for washing, and they are not interchangeable. Both clean through saponins, and both produce far less foam than a shampoo. What separates shikakai is what the hair feels like afterwards. Its Sanskrit-derived name says as much: shikai means fruit for the hair, and it has been the washing herb of Ayurvedic hair care rather than a general-purpose cleanser.
Radico Organic Shikakai Powder is milled Acacia concinna, grown on our own certified organic farms. One ingredient in the pouch and nothing else. It carries no pigment, so it will not colour hair or shift a herbal colour you already have.
If you are choosing between the two
Reetha
Sapindus mukorossi
A wash and nothing else. Cleans thoroughly, leaves the hair clean, and asks you to condition separately if it needs it.
Shikakai
Acacia concinna
Washes and softens in one step. Hair comes out easier to comb through, which is why it became the traditional choice for hair specifically.
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They can also be used together, and traditionally often were. Neither is a stronger cleanser than the other in any way we have measured — the difference is in what is left behind, not in how much is taken away.
What each herb is for
Radico makes eight single herbs you can buy on their own. They are not variations on one another — they do three different jobs. (Our colour formulas draw on a wider set, including henna, indigo and manjistha.)
Cleanse
Used in place of shampoo. Both foam gently from natural saponins.
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Reetha
Sapindus mukorossi
A gentle wash, nothing added
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Shikakai
Acacia concinna
Washes and softens in one step
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Scalp and roots
Worked into the scalp with the fingertips, where hair begins.
Strand
Drawn through the lengths, where the hair itself needs help.
Two of the eight touch colour. Amla cools and deepens a henna result — which is exactly why it is in 23 of our 24 shades, as a deliberate part of the recipe. Colorless henna is named for what it does not do, but a long application can leave a faint golden cast on white or very light hair. The other six — including shikakai — are colour‑neutral and can go into any Radico shade without changing it.
- Botanical name
- Acacia concinna
- Plant family
- Fabaceae — the legume family
- Part used
- [SEED_OR_POD]
- Key compounds
- Triterpenoid saponins — the plant’s own surfactants
- Acts on
- Cleansing, and the feel of the strand afterwards
- Lather
- Thin and short-lived, as with reetha. It cleans without the foam you may be expecting
- Effect on colour
- None
- In Radico’s shades
- In 1 of the 24 — Sun Blonde alone, the same as reetha
Composition
What is actually in shikakai
Radico Organic Shikakai Powder has one ingredient: milled Acacia concinna — the dried pod and the seed inside it, ground together — grown and processed on our own certified organic farms. Nothing is added.
Like reetha, it cleans through triterpenoid saponins: molecules with a waxy, oil-loving core and a water-loving chain of sugars. That architecture is what every soap and shampoo uses, and it is why a plant can wash hair at all.
A named saponin
Concinnoside B
A triterpenoid saponin, and one of several the plant carries. Its sugar chain includes an amino sugar — an N-acetyl group, which is why the formula carries a nitrogen that most saponins do not.
- Formula
- C43H67NO13
- Mol. weight
- 806.0 g/mol
- PubChem SID
- 275754598
A note on names. The same structure appears in PubChem’s compound records as acaciamine, reported from other Acacia species. That is a naming difference rather than a different molecule — and it is part of why shikakai’s chemistry is harder to pin down than reetha’s, whose two principal saponins each have a single clean entry. We name the compound class as well as the compound, because the class is the part we are confident describes the whole pouch.
We measured the pH, and it surprised us
Shikakai is widely described as acidic. We have not found anyone publishing a number, so we took one.
Across repeated measurements the reading moved between about 2.1 and 3.0. We give the range rather than picking a figure from inside it: this is a suspension of milled plant material, not a clear solution, so the probe reads whatever happens to be against it, and that is not uniform.
Then we diluted it, and nothing happened. At one part powder to six parts water — half the concentration — the shikakai reading stayed in the same range. We ran the same test on reetha as a control: its pH rose, from 4.90 to 5.04. Small, but it moved. Shikakai did not.
| Reetha | Shikakai | |
|---|---|---|
| Mixed at 1:3 | pH 4.54 to 4.90 | pH 2.1 to 3.0 |
| Diluted to 1:6 | Rose to 5.04 | No change |
| Consistency | A pourable liquid | A pourable liquid |
That is the signature of a buffer — a weak acid sitting alongside its own conjugate base, holding the pH steady against dilution. Both herbs buffer to some degree: an unbuffered acid would have risen by around 0.3 on doubling the water, and reetha rose by 0.14. Shikakai holds far more firmly.
It has a practical consequence worth knowing. Making the mix weaker does not make it less acidic. If you want a milder wash, use less powder or leave it on for less time — adding water will not do it.
Both are acidic. Shikakai is markedly more so — and this, we think, is a large part of why it became the herb named for hair rather than the general-purpose one.
What acidity does to hair
The outside of a hair is covered in overlapping scales, the cuticle, laid down like tiles on a roof. How flat those scales lie is most of what we perceive as smoothness. Flat scales let a strand slide past its neighbour; lifted scales catch on each other, and hair feels rough and tangles.
Alkaline conditions lift the scales. Acidic conditions let them lie down. That is the whole reason conditioners, acid rinses and every “pH-balanced” claim on a shelf exist — and it is why washing hair with true soap, alkaline at around pH 9, leaves it rough.
Shikakai does its cleaning at the opposite end of that scale. The wash and the smoothing are not two steps here; they are the same step, which is what people mean when they say shikakai conditions as it cleans.
What we notice. Hair comes out of a shikakai wash easier to comb through than we expect it to, and more so than after reetha. We are reporting that as an observation rather than a measurement — combing force can be measured properly and we have not done it. What we can say is that the pH readings give a reason to expect the difference.
What a pH of 2 also means
We would rather set this out than let the number sit there sounding like a straightforward virtue.
pH 2 is strongly acidic — the region of lemon juice. Hair’s own surface sits at 4.5 to 5.5, and cosmetic products designed to smooth the cuticle are usually formulated between 3.5 and 4.5. Shikakai, as it comes out of the fruit, is below that.
It has been used this way for a very long time, and it is on the hair for two or three minutes before being rinsed away, which is a different proposition from something left on. But a few things follow:
- Do not leave it on. This is a wash, not a mask. Two to three minutes, then rinse.
- Rinse thoroughly. Longer than feels necessary — the aim is to leave nothing behind.
- Diluting will not soften it. The buffer holds the pH steady. Use less powder or less time instead.
- Avoid it on broken or inflamed skin. Acidic material on a compromised scalp is not a good combination, whatever its origin.
- Keep it out of your eyes. Saponins sting, this is milled fruit so undissolved particles can lodge and keep stinging, and the acidity does not help. Tilt your head back, rinse with plenty of cool water if any gets in, and do not rub.
Being a plant does not make a number gentle. What makes shikakai reasonable to wash with is how briefly it is on the hair, not that it grew on a tree.
What we will and will not claim
The pH figures above are our own, taken on a calibrated handheld meter from mixes made the way we describe on this site. They are not laboratory certificates, and water hardness will move them. We publish them because they are numbers you can check yourself with an inexpensive meter, and because we have not found anyone else publishing any.
What we have not measured is any outcome. We have not compared cleaning efficiency against a shampoo, and we have not measured combing force against reetha or anything else. We are not claiming superiority on either count — we would need controlled comparisons to say that honestly. The mechanism is well established; the outcomes in our own hands are observation.
Published work on Acacia concinna covers a range of biological activity, most of it concerning extracts in laboratory conditions rather than milled pod on a human scalp. We are not claiming this powder treats any scalp condition, and in the United States a cosmetic may not make that claim.
Radico Organic Shikakai Powder is a cosmetic product for external use on hair and scalp. It is not intended to diagnose, treat, cure, or prevent any condition. Acacia concinna belongs to the Fabaceae family. Patch test on the inner forearm 48 hours before first use, and stop use if irritation develops.
In practice
What using shikakai looks like
Shikakai is a wash, not a mask. You mix it to a pourable liquid, work it through the scalp for a couple of minutes, and rinse it out. The pH reading changes how that should be done — not dramatically, but in ways worth knowing before you start.
- On the hair2–3 minutesDo not leave it longer
- ConsistencyLiquidNot a paste — it pours
- Effect on colourNoneSafe on coloured and uncoloured hair
One part powder, three parts water
By weight. At that ratio shikakai makes a thin, pourable liquid rather than a paste — which is what you want for something you are going to wash with. A paste would sit on the hair; a liquid runs through it and reaches the scalp.
| Hair length | Powder | Warm water |
|---|---|---|
| Short to chin | 8–10 g (¼–⅓ oz) | 25–30 ml (1 fl oz) |
| Shoulder length | 10–15 g (⅓–½ oz) | 30–45 ml (1–1½ fl oz) |
| Long or very thick | 20–25 g (¾ oz) | 60–75 ml (2–2½ fl oz) |
Weigh the powder rather than spooning it — a spoonful of milled pod can vary by as much as a third depending on the spoon and how it is scooped. A 100 g pouch gives roughly seven to ten washes at shoulder length.
If you want a milder wash, use less powder. Do not add more water. We measured this: at one part powder to six parts water the pH did not move at all. The mix buffers, so diluting it makes it thinner without making it any less acidic.
Washing with it
- Mix and let it stand 5 minutes. Stir the powder into warm water and leave it. The saponins need a moment to come out of the plant material.
- Wet your hair first. Shikakai works on wet hair, the same as any wash.
- Pour it onto the scalp in sections, not all in one place. It is thin, so it will run — work in parts and tilt your head back to control where it goes.
- Massage the scalp for two to three minutes. This is where the cleaning happens. Expect very little foam; that is normal and is not a sign it is not working.
- Rinse thoroughly, head still tilted back. Rinse for longer than you think you need to. This is milled pod and seed, and fine particles settle at the nape and behind the ears.
Three things the pH reading tells you
- Do not leave it on. Two to three minutes, then rinse. At around pH 2 this is not something to sit on the scalp while you do something else.
- Diluting will not soften it. The pH holds steady on dilution — use less powder or less time instead.
- Keep it out of your eyes, and off broken or inflamed skin. Saponins sting; undissolved particles can lodge in the eye and keep stinging after rinsing; and the acidity does not help either. If any gets in, flush with plenty of cool running water well past the point it stops hurting, and do not rub. If irritation persists, see a doctor.
How often: two to three times a week suits most people. Shikakai removes oil without stripping, so it does not need the daily frequency a strong detergent shampoo trains hair into.
If you are coming from a sulfate shampoo, expect a few weeks of adjustment. Scalps that have been washed daily with a strong detergent tend to produce oil at the rate that washing demands, and that rate takes time to settle.
Using it with reetha
The two were traditionally used together as often as separately, and there is nothing to stop you. Blend the dry powders first, then add water at the same one-to-three ratio.
Equal parts is a reasonable starting point. More reetha gives a cleaner, more neutral wash; more shikakai gives a more acidic one and, in our hands, a smoother result to comb through.
A blend will land somewhere between the two readings we took. We measured one: our ready-made Hair Treatment Powder, which is shikakai, reetha and amla blended, reads pH 3.50 — and at that pH it can be left on as a mask, which shikakai alone should not be.
Shikakai and colour
Shikakai is in 1 of Radico’s 24 shades — Sun Blonde alone, the same as reetha and the fewest of any of our eight single herbs. That makes sense: this is a cleanser rather than a colour or conditioning herb. It carries no pigment, so washing with it will not shift a herbal colour you already have.
One thing worth timing. Do not wash with shikakai immediately after a plant colour. Henna and indigo both keep developing for up to 72 hours after application, and a surfactant wash inside that window will take some of the result with it. Give it two to three days. This matters more with shikakai than with reetha, because the acidity is working on the cuticle at the same time the colour is still binding to it.
The rest of the range
Shikakai is one of eight single herbs Radico makes for hair — and one of two for washing.
Organic Shikakai Powder See all Ayurvedic hair care
Single ingredient in every pouch. No fillers, no fragrance, no synthetic preservatives.