How often should you cut medium-length hairstyles?

I've had below shoulder-length hair for a few years, and recently cut it to about a 1/2 inch above my shoulders. I know long hair is supposed to be trimmed every 6-8 weeks, but how often should medium-length hair be trimmed? I was thinking it was something like every 4 weeks, but it seems like that is not often enough to maintain the style. My hair is also kind of dry and damaged. I've been taking biotin, a b vitamin that helps strengthen hair, and I think it makes it grow a little faster. Also does anyone have tips for strengthening hair that will not make it grow faster, like certain supplements? I really want to maintain this current length, and I want it to be healthy, too.

How often should you cut medium-length hairstyles?
Cut it every month and get Herbal Essence "Dangerously Straight" (or curly, pending on your hair).I blow dry and straighten my hair everyday so it can get pretty damaged, but this method usually works for me.
Reply:Get "Herbal Essance," and cut your hair every 3-4 weeks. Hope it works!
Reply:Every month.
Reply:it is fine to get it cut about every six weeks, it depends if you color it, how often you wash it, if you swim and how many vitamins you take. The best bet is every 6 weeks but talk to your stylist who would have a better recommendation for you because she would be the one person able to see your hair and tell you