It is normal to have yellow armpit stains

Have you tried drinking water instead of oil?

It's caused by many antiperspirant deodorants. Switch to one that doesn't stain.

It is mostly from stick deodorant. You can remove it with dishwasher detergent.

every shirt i own has gooey yellow pit stains on them, i was hoping it was normal, and i've tried six different deodorants with the same outcome, i never see anyone else with them so i just figured they wear undershirts. i cant wear 2 shirts like that or i get way too hot, and there's very few things i hate more in this world than being hot

I have this happen on white business shirts. It doesn't seem to matter if it is man made fibers or cotton. After awhile they become stained permanently; no amount of bleach seems to help. I'm sure my co-workers notice.

Once the yellow stain starts creeping into my shoulder area where you can see it without me raising my arms. It is time to throw it away.

I have very sensitive underarms, most brands of anti-persperant burns and eats away at my skin. So I try the weakest kind there is, but then it doesn't work well. Or usually I don't wear any and just smell like a man at the end of the day. I love the smell of my own sweat, maybe because I'm gay, I don't know.

Totally normal!
I get it too, mostly when I wear white or light coloured shirts.
Ways to avoid ruining your shirts are don't wear it too long or wear a diff shirt underneath.
Avoid light coloured shirts if you know you are going to be sweating alot.
Deoderant doesn't prevent, I wear it and I don't stink or anything, but my pits still sweat.
Pitstick just prevents stench, not sweat.

It is absolutely normal. The nody produces a couple different types of sweat- nervous sweat is rank and oily. <a href="http://Howstuffworks.com" rel="nofollow">Howstuffworks.com</a> has an interesting podcast and probably an article about sweat. I listened to it recently.

No. Try a natural deodorant or try changing your diet.
See if that helps, if not see a doctor.