You know, I used to be really big on not trimming for 3-4 months, but I have since given that up.
How often you trim really depends on your hair. Some people can go longer without trimming, while others have to trim every 4-6 weeks.
For me, going 3 months was too long. My ends would look ragged by the time that 3 months rolled around. I am now trimming every 8 weeks (2 months), which I have done at the same time I get my touch-up.
I am due for a touch-up in about 2 weeks. I have a TON of new growth thanks to the MTG. I hope I can survive the next two weeks. The MTG also makes my hair more manageable, including the new growth.
I know people want to see pictures and such; maybe some still aren't "believers", but I wouldn't lie to you. I've been a member of this board about 3 years or more, and a lie has never emitted from this keyboard.
If I tell you MTG makes your hair grow, IT DOES!