As a teen female I'm always sleepy. Low energy all the time & I was wondering if T would help with that or no? Because vitamin b12 doesn't even help.. sleeping longer doesn't even help lol. I know this fatigue was caused from my depression but some people think its just an teenage phase. What do you think? Will T help?

There are many things that can cause fatigue... lack of exercise, lack of proper nutrition, caffeine usage, medications, anxiety, depression, stress, sleep, anemia, various diseases, etc, etc, etc. If you're transgender and looking to start T but not sure of what you can expect talk to your endo first and let them know about your fatigue. If you're not transgender and just looking to self diagnose here you should visit your regular Dr and discuss with them so they can make a proper diagnosis.

I'm a little confused by this post.  Do you want to take T for gender-related issues and are looking to have the possible side effect of 'energy' as a benefit or are you a female-identifying person without gender issues looking for a solution to feeling tired and think that T would be helpful?  I basically ditto Overdrive.

I actually needed more sleep once I started T. I went from feeling well rested on about 7, and now, if I dont get 9 hours I have trouble getting through the day.

I went through a period like that. It could be life+school+friends+depression+->-bleeped-<-=a big mess that only time will fix.