I tried it, and repurchased once to make sure it wasn't working. It didn't do anything amazing for me. Now, part of my issue may be what is causing my hair loss (health related, and nothing I can really do much about - well, a combo of health related PLUS a medication. Staying on said medication helps with my quality of life, so I guess I'll deal with thinning hair). I think maybe it may be more beneficial if your hair is thinning due to stress or you just want it to appear fuller. I think thta my hair does better with Pureology and Redken shampoos and conditioners (and occasional L'oreal). I kept trying the Invati scalp spray and prefer Alterna's - definitely notice a difference, although it is subtle. I puchsed L'oreal's and am giving it a shot for a month or so (mostly b/c eek it is SO MUCH cheaper! It's less than $10)..
but yeah, noticed no real difference with using Invati. I'd say it's worht a shot b/c I've returned things to Aveda (but only after a short period of time b/c I hated the smell or I had a reaction). Not sure how long you need to use it to see a difference - I used it for several months (at least 3-4, maybe 6 or so?)