Keep in mind: We don't add any perfumes, synthetic fragrances, or fragrant essential oils to our Hair or Beard dyes. We kept them out to let you control the experience (many of these additives are known allergens and cause adverse reactions—not what "natural product" customers want).
Henna, indigo, and all the additional herbs, have their own natural scent. All ingredients are green plants and flowers, so they will smell like powdered plants. Hey—they're a zillion times better than inhaling the chemically strong, noxious scent of traditional retail brands. Many retail brands have warnings about esophagus and lung burn potential if chronically inhaled!—yikes!
HCL always recommends to apply without added fragrances. However, if the natural scent disturbs your henna coloring process, then you can try adding some all natural, organic essential oils*; fragrances range from lavender to clove to patchouli. Careful: add just a few drops prior to application as you mix your henna powder.
*some essential oils can react with the lawsone pigment release in henna (make darker stain and/or alter shade) and provide unpredictable results. Go easy and a strand-test is always recommended.