Doxycycline + Water = Red Water?

[BDs]

My water turns red, is this a normal reaction?

 

[BlueShadow]

It is hard to say. Different formulations of doxycycline may have dyes or such added to them, to explain the red color. However, all of the doxycycline I have seen (all 2 brands, LOL) were white and remained white when dissolved in water. So this does initially seem odd to me.