How many months can hubby take LR for???

I can't remember where I read it, but I remember when I was planning my sway, I read somewhere that hubby should only take LR for a certain number of months then take a break..... Is it 6 months or something like that?. He's been taking it for 4 months now from cd 1- cd 14 then stops, then again the next month from cd1-cd14 then stops. hubby is 35 and I'm 37.
Thanks x

6 months and then take a cycle off

officially it's 6 months then one cycle off, but honestly if you've gone on 6 months not getting pg it's time yto drop it anyway.