I hear this question regularly and I read the debate online often about many different items and traditions. My personal answer is an emphatic "no, henna itself is not disrespectful." I don't say this lightly. Much time, research, and thought goes into my statement, "no, it is not disrespectful for Westerners to use or wear henna". Not only do I say it's not cultural appropriation, I'd argue that the West has enriched the henna tradition in ways that have never been done before!
In my experience, the idea that henna is cultural appropriation, has been from the Indian and Pakistani community. Perhaps this is because I am closer to these communities since Asad (my other half) is Pakistani-American. People making this claim, generally argue that henna is Indian in origin and Westerners using henna is disrespectful of the culture and religious sensibilities of India.
Henna is not originally from India. Our first evidence of henna is over 5000 years ago in Egypt. Henna was found on the hair and the nails of mummies. Some of the first evidences of henna as body art is in Syria about 4000 years ago. We have further evidence of what was possibly henna used throughout the middle east in ancient Goddess worshiping cultures 5000-3000 years ago. We also have possible evidence of henna use in North Africa during this time. It seems henna was not used in Indian until around 500 BCE at the earliest, only 2500 years ago.
The amazing thing about henna is that it wasn't started in one single area and brought to other areas. It looks like henna developed independently in places where it grows well and brought to even more areas from these many different points. Essentially henna has no single birthplace!
Even more interesting, I think, is that henna has history in most major religions. I think many Westerners think of henna as being a Muslim or Hindu thing, but henna has a rich history of use in the East in both Judaism and Christianity along with ancient religions such as the ancient Goddess religions that I mentioned earlier. Henna's history predates Judaism, Christianity, and Islam.
This means henna has no owner. Henna is an equal opportunity art and should be embraced by anyone interested in it, no matter what their ethnicity!
Every culture henna has touched, has enriched the art of henna in unique ways.
About Cultural Appropriation...Though no one culture "owns" henna, there is something to be said for a white girl like me doing something that Indian, Pakistani, or other ethnic women may have taken heat for in America. The very fact that some women and girls have dealt with discrimination for being "different" because they wore/wear henna, bindi, or even their traditional clothing means we should consider what it means for us (by "us" I mean white girls like me) to wear these same things.
Being educated about henna and acknowledging the plight of others is a good start to being sensitive. Being willing to have open conversations about henna and cultural appropriation, and educating others about henna are also helpful. Understanding what the West has done to enrich the art of henna is important too.
Most importantly, we should guard against our own hidden biases and bigotries. We should be aware of our own privilege and try to see things from other people's point of view.
What has the West, in particular the USA done for henna?Many folks see the West as having commercialized henna with festival henna booths offer tattoo-style henna to tourists. I'd argue that you see that in tourist areas in India, Morocco, and other places in the world as well. I'd also argue that we in the West have advanced henna to a degree never done in history in such a short period of time.
The West has introduced henna to science! Western pioneers such as Catherine Cartwright-Jones have explored the science behind henna to find out how and why henna works. This has lead to major improvements in the safety and quality of henna stains. We no longer do things just because we were told "that's how it's done." We now do things based on the actual science of henna.
It's easier than EVER to get great henna stains from natural henna without jumping through weird (and sometimes gross or dangerous) hoops. For example, we no longer mix into our henna or cover our skin with camel urine to get better henna color...whew!
We know which essential oils work to give henna better color and why they work. We know which essential oils are safe in our henna and we know how much essential oils is safe to add to our henna paste. We know to add the oils to the paste and not directly to the skin which is unsafe.
We've also enriched the art of henna! North American henna artists have taken it upon themselves to deeply research different styles of henna. We can now identify the foundations of different henna styles from all over the world including Indian, Pakistani, Gulf, Arabian, Moroccan, Mauritanian, and more. We have also mastered the art fusing different styles together. I'd hazard a guess that we have some of the best henna-educated henna artists in the world.
So, enjoy wearing henna! Enjoy doing henna!
Embrace the West's modern contributions to henna while honoring the history of henna.