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.