I am a researcher by nature and I too purchased Shikaki when I completed my Henna research. Along with a few others - Brahmi, Maka, Tulsi, Amla, and neem.
(I am a proud PJ, but it's fun for me.
)
Warning: please sift your powders especially if your hair is kinky/coily. I took a major L during one experiment.
ETA: CMW your hair looks great. I love the density.