Yes, just make sure that you ask the artist what is in their henna paste, they should be able to tell you, and it should be a simple recipe, for example, I mix my henna paste with:

• henna powder
• lemon juice or water
• lavender, or tea tree essential oil
• sugar or molasses

So basically stay away of any henna that looks like these "henna" cones in the image below:

Good luck, I'm sure you will find an experienced artist who mixes their own paste!