i read online that hair plus shampoo and conditioner can make your hair grow longer in only 28 days! is this true? does it really only take 28 days to get longer? and on average, how much longer?

Nothing makes you make your hair grow faster in a matter of days. It takes time, usually a month or more to see your hair grow half an inch or more. It all depends on your genes and your type of hair. Don't believe fads like that; just use a good shampoo and conditioner, and eat a diet full of antioxidants to promote hair growth. That's all you need.

Even without washing, your hair will get longer if you wait 28 days.

i dont know but if u try it & it work i would love to use it
of course dear we are all the same there is nothing
like long hair i had my hair cut for about tow years
& it still look the same so hard to grow faster ,
first u use a good hair shampoo & use all kind to
condition it then eat sea food with lemon its good for the hair
& tablets like hair & nail & there is the last
solution & the best called minoxidil 5% drops they are
like the best i used it until now am in da 4 forth
month u should use them for 6 month then u stop
using it twice a day u start after 6 month to use
it for 1 time aday and after a week 1 time every tow
days & less until u stop be careful u cant stop it once .

Don't think so. but putting your hair in ponytails pulls the hair out of the skull.

No, your hair grows from the roots, not the ends.

The only thing to make your hair grow faster is the way you eat. nothing you put ON your hair will help- hair grows from the roots, not the hair itself. I have tried TONS of things to get my hair to grow faster. There is this one pill that you can take that makes your hair & nails grow faster and stronger. It's called Biotin. You can buy it at Target for less than $3. It takes about 2 weeks to start to see results. Hope that helps!! =]