Identifying Indigo for Hair and Indigo Dangers – KNOW your indigo, or at least know which indigo is safe to colour hair

There are many types of indigo plants, and some are poisonous. The indigo which I sell, and which I consider safest for hair, is the powdered leaves of the indigofera tinctoria plant. It’s a greenish colour powder that looks a bit like henna but smells different to henna; it has a strong odour.

A satisfied customer from Italy, who wishes to remain anonymous, wrote to me recently and we engaged in the following e mail dialogue which I am reproducing here as I feel it is a beneficial discussion containing valuable food for thought :

Indigo Dialogue



: “Hello! I’m a happy customer of yours and buy indigo from you since I’ve started using henna and indigo together. (I’ll probably be doing a repeat order in the next couple of weeks.) It works beautifully and my hair hasn’t been in as good a condition for years. However, I recently came across this webpage. it mentions several species of indigo. I know you stock indigo tinctoria, but given (according to this site) there are several species of indigo some of which are very poisonous, please could you reassure me that you know about this and also know that your suppliers for indigo are equally skilled in distinguishing between these subspecies of indigo.

Many thanks
Anon, Italy



: Thanks for taking the trouble to bring this site to my attention. Yes, I am aware that there are many different species of indigo, and that some are poisonous.

However, as far as I am aware, and my supplier ( who is knowledgeable about species of henna, indigo and cassias – there’s only one henna in fact, but different flowers and plant structure depending upon maturity / immaturity sometimes give the impression of there being more species of henna ) , powdered indigofera tinctoria leaves have been used safely for centuries to colour hair. But I have to say that there is little in the way of scientific analysis that either proves or disproves “safety”. I’ve always considered it beneficial , and certainly safer than hair dyes. However, you may be interested to look at the links on the website home page under “Is henna safe?” – you’ll see a link there to a European Commission paper on indigo ( and henna ) which make scary reading. Nothing is certain, but I personally feel, given the lack of conclusive & trustworthy scientific research / evidence, that indigo and henna have to be looked at with a balancing exercise approach – in my opinion they are far safer than chemical hair dyes. The problem with the European scientific papers is that they are conducting an analysis of the extracts ( of henna) and focusing largely on fermented indigo, and they have not conducted “human studies” i.e. indigo experiments on humans.To the layperson who is looking for scientific assurance that indigo is safe, as far as I can understand or see, there is no such assurance available in the scientific community. But I would argue that 1. hair dyes are just so blatantly unsafe and 2. henna/indigo have been used safely for centuries, and that these two factors alone add up to making henna / indigo the safer option for colouring hair over hair dyes.

Do have a look also at the henna tribe thread on this topic here – I’ll give hennacat a nudge to post her information up.

All best wishes Sabrina.”



: “I’m inclined to agree with you with respect to looking at this as a relative risk thing. As someone who became sensitised to permanent dyes, I’m very happy with my henna/indigo results. Btw I have extremely sensitive skin and react to lots of things, but have no trouble with either henna or indigo thankfully.

Also I’ve done a bit more digging and found that the method of extraction can be critical. (I’m sure you know all this btw) If indigo is chemically extracted, as it is for use in fabric dyes then other chemicals that truely are known to be harmful to people can contaminate it. This would not be the method your suppliers use, as it results in purple crystals, not green powder. However, it’s labelled as indigo nonetheless. I read on a forum today of someone getting indigo from a Chinese herbalist and noticing that instead of the green powder it was purple crystals, eek. The ’herbalists’ obviously didn’t know the difference, which is worrying. Think of the possible consequences. Someone becomes ill, gets taken into hospital and they find out the problem is indigo, which is true, but not the indigo they should have been taking. This is leaving aside the problems people have with ’black henna’ and the ppd issues. So there’s a lot of potential bad indigo press to counter, none of which are the lovely product you sell.I shall certainly continue with henna and indigo for reasons I’ve already stated. My scalp’s happy and I’ve got my hair shine back. I’m also very happy with your product and hope you do good business, as there are precious few trusted indigo sellers in Europe. More generally I hope the method continues to grow as there are a lot of happy henna only or hennindigo heads out there and there are also a lot of people (like me a year or two back) who really wanted an alternative to the dyes available from salons or the chemists. with best wishes”


: “Thanks for your reply Anon. I think your initial question, and subsequent comments are extremely valuable in focussing our minds on safety issues and on the decision making process to be applied in making a reasonably informed decision about henna / indigo, given the lack of information and conclusive scientific research.

I had another customer contact me a week ago to say they had bought indigo from a herbalist in India and that it was blue and was that the true indigo as opposed to the one I’m selling – the blue indigo is the “vat indigo” , i.e. fermented, and probably ( but not necessarily – you’d have to ask ) having undergone an extraction process in which chemicals are used. Now that is scary – an ayurvedic – specialist – herbalist in India passing off fermented chemically contaminated indigo as pure indigo for colouring hair ! And a year ago, an India trader sent me a trade sample of indigo for hair colour – again, it was the blue powder chemically contaminated stuff. And unfortunately, you’re bound to be right – this sort of misinformation /misunderstanding is going to rear its ugly head time after time until there’s enough public awareness of what “pure indigo” is and what “pure henna” is.

Anyway, thanks again for triggering an interesting, and crucial, dialogue in the world of henna / indigo hair dye ! Best wishes always”



: “Thanks again for your reply. As many of the new henna and/or indigo users get to hear about it from the web, I think the only thing for all of us to do is just post as widely as possible what ’real’ indigo looks like, it’s botanical name and what vat indigo looks like, as well as the ’black henna’ quagmire issues! and then hopefully this will protect as many people as possible and also hopefully put shark sellers out of business.

Do you mind if I link to your site at a haircare forum I post on specifically addressing this issue?

Many thanks”

So, what are the other types of indigo ? And which ones are safe ?

Well, I’m not an expert on indigo so I’m not the best one to tell you about the different species that exist – my speciality and my interest is purely the powdered leaves of the indigofera tinctoria plant alone and that’s the one I sell.

Here are some links which tell you about all kinds of indigo, and about indigofera tinctoria – just to give you an idea and to alert you to the fact that there’s not just one type of indigo. You’ll see references in some of these links to indigo being fermented. Can I just clarify here that my indigo is not fermented, or “extracted”, and neither is it “indigo vat dye” ( to which, IN MANY CASES BUT NOT ALL, chemicals are added ) ; my indigo is purely the crushed leaves of the indigofera tinctoria plant and has nothing added to it, and it colours hair. It’s green and not blue. The blue indigo has generally undergone some sort of change or treatment, or it comes from a different plant : – USEFUL RESOURCE FOR LEARNING ABOUT INDIGO & WOAD COMMON MEDIEVAL PIGMENTS BLUE WILD INDIGO PLANT ( NOT INDIGOFERA TINCTORIA) – INDIGO DYE

Indigo in Bengal

A Word about Indigo

DON’T try using indigo alone on any light hair colour (blonde hair colour / ash hair colour ), including grey hair, as it has the potential to produce blue or green and it may not be a shade you like ! But if you’re interested in blue or green, then go ahead and strand test. On dark hair colour it is generally considered safe to use indigo alone and it will darken the hair even more towards black hair colour, but it may leave the hair dull and dry and it will lack the glossy effect that comes when it’s used with henna.

On grey hair, make sure the hair is orange from your henna before using indigo. And if the grey hair looks bluish after using indigo ( rare, but it could happen if henna didn’t cover it properly), then just repeat the henna application followed by indigo again.

Always do a strand test and even if you like the idea of using indigo on its own, do experiment by using it after henna hair colour as well. I personally find indigo is best used with henna for optimum results and spectacular hair colour.

What happens if you indigo grey hair or white hair without using henna first ?

This is what happens, as demonstrated by Maryam :

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Maryams’ Grey Hair ( roots are showing through after previous henna / indigo applications)Indigo straight on to grey hair / white hair turns it a blue greenHenna on top of the indigo blue green hair turns it back to henna orange brown
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Now the indigo result after henna !



Patch Test

Some people would say it’s ridiculous to even suggest a patch test for anything as natural as henna, indigo, and cassia obovata. Although it’s true that these products are exceptionally safe to use – let’s face it, they’re a life saver compared to the chemical alternatives – the fact remains that we also have to acknowledge that in this day and age of allergies, allergic reactions, and haywire immune systems, a patch test is generally regarded as sensible [for any product] to check for allergies. Remember that even though these colour dyes come from plants, they can cause allergic reactions as well ! I’ve developed an allergy to vegetable derived glycerine on my face! Vegetable derived glycerine is a natural product, although I imagine it’s the stuff used in the extraction process that’s causing the problem. The point is, don’t assume that because something is “herbal”,“natural” or “organic” it means allergy free. Very few people, if any, will experience allergy symptoms from pure henna, pure indigo, and pure cassia obovata but it’s best to test and to be safe.

First time users are reminded to start out with the Renaissance Henna Hair Colour Kit which comes complete with a detailed instructions booklet suitable for absolute beginners.


How to do a Patch Test

Pre-mix a small quantity of henna powder – about 5gms – according to the instructions in the Renaissance Henna Hair Colour Kit, and apply the paste to the inside of your arm or elbow crease. You can tie an old piece of material (cotton or muslin), or some plastic wrap like cling film, around the arm to keep the paste in place. Henna will stain the skin red / red orange. Wash off a couple of hours later and wait 48 hours. If you experience no irritation in that time then it’s reasonably safe to assume you can use it without any problem.

Next, do an indigo patch test. Mix up about 5gms of indigo hair colour into a paste according to the Instructions in the Kit and wash off after about an hour or longer. Indigo may stain your skin a bluish colour. Wait at least 48 hours. If you experience no irritation in that time then it’s reasonably safe to assume you can use it without any problem.

Similarly, do a patch test for cassia obovata. Leave on for half an hour or longer and wash off. Cassia obovata should not stain at all, but if it does stain it should be an exceptionally light yellow to light orange colour and it should wash off or fade within about 24 hours.

The skin stains are nothing to worry about. Provided you’re not allergic to these plants, the application of henna, indigo, and cassia obovata is probably good for you. If you do not experience any irritation, it’s fine to go ahead and use Renaissance Henna hair colours and hair conditioning products.


Always do a Henna Hair Colour Strand Test and an Indigo Hair Colour Strand Test

Although a strand test may not be a fantastic indicator of your end result colour – it’s usually a lame indicator in comparison to the real thing – it’s still essential. You want to be sure that you are not averse to the likely colour or range of hair shade colours that you might achieve with henna hair dye or henna plus indigo. The best strand test result is achieved by testing a small chunk of hair on your head from as close to the nape of you neck as possible ( that way it’s unlikely to show too much if the result is not what you want ). Get someone to help you section your hair, apply the paste, and cover it (try cling film / saran wrap, wrapped around it) to avoid staining the rest of your hair. If you don’t like the idea of testing your hair this way, then wait till you have a trim and ask your hairdresser to put aside enough of your hair for testing. If your hair isn’t long enough for this kind of strand test or cut hair test, then collect enough hair from your hairbrush for hair colour testing, but generally this gives disappointing results.