How long for new hair?

[spidermom]

Idle minds are the devil's workshop. So I've been wondering lately -- if I were to dye my hair a drastically different color, such as devil's butt red, how long would it take for all the dyed hair to shed out to the point where nobody can tell I ever dyed it? Has anybody gone through this or seen it happen? I know that a few of you have been growing out dye for a long time. Who's been growing out dye for the longest, I wonder?

(ETA: No cutting off the dye, only letting it all shed out.)

[Alley Cat]

Wouldn't you have to work out how long your hair was , how fast it grows and work it out from there. Say at hips you are about 34 inches that's at an average of 1/2 inch a month 78 months which would be 6 and 1/2 years. :shrug:
A long time. It wouldn't all shed out it would grow out. Some of it would shed but most of it would grow out. Well you have me confused Spidermom? :confused:

[Morticia]

Last year, I had a one-inch strip of my hair bleached so that henna would stain it burgundy. It was a section of hair behind my ear, so it could grow out without obvious roots. Right now, the section of hair is black until past my shoulder, where there is a clear change in color.

[spidermom]

Wouldn't you have to work out how long your hair was , how fast it grows and work it out from there. Say at hips you are about 34 inches that's at an average of 1/2 inch a month 78 months which would be 6 and 1/2 years. :shrug:
A long time. It wouldn't all shed out it would grow out. Some of it would shed but most of it would grow out. Well you have me confused Spidermom? :confused:

Well, you know, every single hair on your head is going to shed out eventually. I'm wondering how long that would take - to lose every hair I have right now and have all new hair. I'm almost curious enough to dye my hair and watch how long it takes before the dye is all gone. But not quite.

[maskedrose]

I guess you would have to average your daily shed rate and then the approximate number of hairs on your head, and then divide the first number into the last number and voila (unless my bad math skills are now out for the world to see :) )

[mommy101405]

I have actually wondered this myself. It must be a really long time though b/c I have seen people with really long regrowth before.

[MusingFrog]

Assuming that all hair grows at the same rate and sheds at the same length, all you would have to know is how long it would be until the newest hair on your head shed.

So lets assume that hair grows for 7 years and then stays on your head for another year before shedding out. Assuming you didn't cut your hair, it would take 8 years before that hair shed (at which point every other hair which was older than that hair would already have shed). Since that would be the last hair with dye on it, it would be 8 years.

Now, that time would speed up if you cut your hair at a certain length. Then you would only have to wait until the newest hair got to that length before it was cut.