Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
I'm have not done this personally but I found some threads with some information for you.
Here's a thread where someone henna'd and relaxed on the same day.
http://www.longhaircareforum.com/ha...w-discussion/5919-relaxer-henna-same-day.html
This thread is specifically about Phyto and Henna but its a bit old. 2007
http://www.longhaircareforum.com/hair-care-tips-product-review-discussion/119678-phyto-henna.html
Hope this helps.