Is it true that white hair can't be treated with laser?

Unfortunately, yes it is. Most laser and IPL systems rely on pigment in the hair shaft and at the root to be present. This is what heats up when the laser is applied. The heat does the work, so if there is no pigment to attract the light, we can’t get enough heat in to destroy the follicle. Sometimes, especially with hair on the face, the actual hair can appear white but have a thick dark root. This type of hair we can often treat, so if in doubt, pluck a hair out of the area you’d like to treat and take a look at the root. A nice thick dark root means a good treatment result is more likely.