Insight please!

[Auburn]

I just dont understand. Hair is dead, right? How can anyone feel/see/tell a difference in their hair's health/thickness/luster/etc from taking something INTERNALLY ? Please enlighten me!

Im not talking about the new GROWTH either, I mean the hair that was there previously.

 

[FroFab]

A difference in luster may be noticed if the scalp is healthier and secreting more natural oils which may be better able to coat and condition the shaft of the hair...

Or maybe not, I'm just throwing out a guess

 

[CurlTalk]

Interesting question.
My guess would be that increasing the body's intake of certain vitamins/minerals/etc will make the new growth thicker/healthier/etc, making the rest of the hair fall a different way (akin to how hair that is relaxed bone straight looks much thinner than when flat ironed at 3 months post; the three months post hair isn't thicker, necessarily: it is the presence of thicker roots that makes the rest of the hair fall a certain way, making it appear thicker).
Also, changing diet/ etc. may alter sebum production, which may account for the hair's luster: as more sebum is produced, more travels down the hair shaft, giving the hair a shinier, healthier appearance.
That was just my two cents; maybe someone else can offer greater insight.

 

[Zaz]

I think maybe it's the same as a leather coat or a wooden table, if you leave either one out in the sun for a while it'll start to crack and dry out, even though they're both dead. But give them a lil TLC, with some leather moisturiser/cleaner, or some wood moisturiser on that old table and it'll regain its luster.
Even if something is dead you can still give it some "life" by making it shiny and new-like again So I think there are definitely some things that can be done (internally and on the outside) that can be done to improve hair even if it is lifeless, I guess it's all about the moisture. When you drink plenty of water for example it hydrates your body (hair, skin..) from the inside out.

 

[Heavenly]

I agree with the posters who said that perhaps things taken internally affect the newgrowth and scalp secretions, which in turn affects the already grown hair to behave in a different way. I know that if my new growth is healthy and strong, the rest of my hair feels better.

 

[LaidBak]

Internal supplements can possibly afffect the luster (as stated by the other posters). But health and thickness of exisiting hair can only be affected by external treatments.
Just my opinion from what I've learned.