Science, Now + Beyond

Is henna actually safe for you to use?

Pay attention to what you put on your body.

You either love or hate the smell of henna, and I love it.

For me, it has only ever meant good times. My earliest memories of henna entail weddings, moon sighting parties before Eid, and my mom trying to teach white kids about our culture by bringing something fun to school. Friends of mine have said on separate occasions that it smells like Christmas and, while I don’t know exactly what this means, it is certainly a positive association.

So what a surprise it was when I learned that there were instances where people had in fact been harmed by henna.

Maybe you have an aversion to the smell and stain sure, it’s not for everyone, or maybe you don’t want to wear it for fear of drawing unwanted attention at work. But allergic reactions? Those were new to me.

And then I heard about black henna which is a very real and potentially harmful concern.

Right now in the United States, it’s wedding season, and part of wedding season is lots of henna.

But what about black henna? What is it exactly? How does it work, what’s the science behind it, and should you be concerned?

Henna in its most basic form is actually relatively conditioning on the body.

It is made by grinding up the leaves of the henna plant and mixing them up with water and a mildly acidic liquid like black tea to form a paste. It is only after this paste is made that the leaves will release lawsone, which is key to the stain. Lawsone is a red-orange pigment, and when henna is applied to the skin, it is lawsone bonds to keratin in the skin to produce a stain. People who have used henna before may have noticed that its color appears stronger on the palms of hands as opposed to their backs. This is due to the fact that the skin is thicker here and therefore more layers of lawsone can be absorbed into the deeper layers of skin. This is also possibly one of the reasons henna tends to turn out darker on women of color than on white women, because skin that already has melanin in it tends to be thicker than skin that does not.

Once the henna has dried and the paste has been removed, the henna oxidizes. This is why it can take a few takes to get that sought-after rich hue.

Black henna tends to work much faster than natural henna, and one of the reasons for this is that black henna typically contains less actual henna and more PPD. PPD, or paraphenylenediamine, is a chemical used in black hair dye (hence the name “black henna”). When black henna comes in contact with the outer layer of the skin, it can cause a reaction in some individuals though not everyone reacts. On people with particularly delicate skin, black henna can cause the skin to erupt in red blisters that can sometimes lead to permanent scarring. Some can become sensitized to black henna as well, meaning that, if you come into contact with black henna once, you can later experience a strong adverse reaction to it even if you did not experience one the first time around.

So what does this all amount to? Should you be worried?

Well, it’s a bit hard to say is everyone should be the same amount of concern. There’s not a great wealth of information as to if and how black henna affects different types of skin. However, it’s safe to say that it is certainly best to avoid if possible.

How can you tell black henna from more natural henna? If it’s coming to you in a powdered form, it more likely to be natural if it is of a greener shade as opposed to a deeper black or brown one. Real henna is also never actually black, neither as a paste nor on the hand, but closer to an orange or reddish-brown, so if it looks black, be wary. Some individuals have also said they can tell a difference in the smell between black and natural henna, but there is more research to be conducted on this whole topic.

Many henna cones sold at your local South Asian foods store lack accurate ingredient lists, so it can be hard to tell what’s in them before use. That’s not to say to avoid them entirely, but rather to test them out on a small patch of skin before a full design. If you’re really concerned, you can also look into getting an allergy test done by a professional. In the meantime, if you’re willing and able to find some, there are some local and independent businesses who make their own natural henna cones so you can know and trust exactly what’s in them.

To be honest, I will probably keep using the low-quality cones I get at my local South Asian store. It’s what I’m used to.

But knowing all of this, when faced with the option, I might try instead to go for the organic option. Either way, I don’t know that I’ll ever want to give it up completely.

Via [Image description: A henna design is applied to an outstretched palm.]
Via [Image description: A henna design is applied to an outstretched palm.]