I mailed Dr Lee a similar question a year ago, his words in bold:
Hi
I've been a user of your Xandrox15 minoxidil solution for approximatly two years and in my recenly purchased bottle the color of the solution is clear instead of the regular yellowish hue.
Is that normal?
It is normal. The color of minoxidil in a water/alcohol solution varies from colorless to dark amber.
does that say anything about the minoxidil concentration/effectiveness of the specific sample?
There is no change in the viability of the formula.
Best wishes,
Richard Lee, M.D.