Or ability to recover instantly?
Bigfoot's went to war for 5 rounds with maybe the hardest hitter in the entire sport, then get's ko'd by Frank mir of all people. Overeem, while obviously steroided to the gills, got dropped by Remy Bonjasky, and recovered instantly. He also took some ferocious shots from Badr Hari, and even though the fight was stopped, he did not even take a knee. Now Overeem goes down with a swift breeze. Hendo's ability to recover instantly is legendary, yet vitor stopped him after the TRT ban. Would Hendo have recovered after fedor dropped him, without TRT?
Do we have any other examples of people who admittedly took special "proteins", or were highly suspected of using, then when forced to clean up, no longer took a punch like they used to?
Hendo was still on trt during the belfort fight. 
Neil McCauley - Or ability to recover instantly?
Bigfoot's went to war for 5 rounds with maybe the hardest hitter in the entire sport, then get's ko'd by Frank mir of all people. Overeem, while obviously steroided to the gills, got dropped by Remy Bonjasky, and recovered instantly. He also took some ferocious shots from Badr Hari, and even though the fight was stopped, he did not even take a knee. Now Overeem goes down with a swift breeze. Hendo's ability to recover instantly is legendary, yet vitor stopped him after the TRT ban. Would Hendo have recovered after fedor dropped him, without TRT?
Do we have any other examples of people who admittedly took special "proteins", or were highly suspected of using, then when forced to clean up, no longer took a punch like they used to?
Hendo was on TRT when he fought Vitor, wasnt he? Bigfoot had been ko'd by Cormier, dropped by Mike Kyle, murdered dead by Cain twice, all while on TRT.
If anything, the battle with Hunt (where he got dropped once or twice and was about to be finished when saved by the ref to check a cut) probably finished off what's left of his chin, and the Andrei fight showed that. Then you factor in the shots he has likely taken in training between the hunt war, and the andrei ko, and you have Mir catching him a punch he never saw coming....done.
Overeem usually gets ko'd after gassing after exploding on somebody, and coming close to finishing the fight, but not getting the W. His defense has gone to complete shit as well. In K1 he liked to hide behind those big ass gloves.
These are also all fighters with a shit load of wear and tear already.
Absolutely zero if you understand how Concussions occur.
I agree with the mindset theory, but even the greatest mindset can still let you get ko'd.
It would allow you to make your neck muscles stronger, so they can take more of the force when you are hit. Neck strength and flexibility help you in taking shots.
But it wont just give someone a stronger chin because they've have a needle in the ass.
Catlin - Absolutely zero if you understand how Concussions occur.I wouldnt be so dismissive...and I too understand quite well how concussions work. The impact of testosterone on psychology is not fully understood. Additionally, extra muscle around the neck supporting the head might reduce the intensity of many concussions, depending on site of initial impact.
Thst said, theres no evidence one way or the other as of yet.
Steroids might cause a healing factor that is happening before the fight which would allow a fighter to heal and be less likely to be knocked out easily..
Once of the juice, maybe the healing isn't there and the brains sensitivity is a lot higher. 
Stea1th - Steroids might cause a healing factor that is happening before the fight which would allow a fighter to heal and be less likely to be knocked out easily..Another distinct possibility. Healthier during camp=healthier during fight. Vu
Once of the juice, maybe the healing isn't there and the brains sensitivity is a lot higher.
Ninja Lee -
It would allow you to make your neck muscles stronger, so they can take more of the force when you are hit. Neck strength and flexibility help you in taking shots.
But it wont just give someone a stronger chin because they've have a needle in the ass.
I'd go with this.
I dont think it would effect the amount of trauma the brain can take during a fight.
Steroids definitely help your chin. They just make you more ferocious and game and that alone helps your chin. Flame away
CowboyRodeMeToAdecision - Hendo was still on trt during the belfort fight.Yeah it was the last fight allowed on trt if i recall. Age has caught up to Hendo. TRT didnt help his chin. He wasnt on trt in the rashad fight and his chin held up pretty well.
Non N00B -Also have to consider that Hunt never really pounced on Bigfoot and almost allowed him to recover. Bigfoot has never really been ko'd by one shot clean. Dropped then gnp finish. The Hunt fight definitely took away anything he had left of a chinNeil McCauley - Or ability to recover instantly?
Bigfoot's went to war for 5 rounds with maybe the hardest hitter in the entire sport, then get's ko'd by Frank mir of all people. Overeem, while obviously steroided to the gills, got dropped by Remy Bonjasky, and recovered instantly. He also took some ferocious shots from Badr Hari, and even though the fight was stopped, he did not even take a knee. Now Overeem goes down with a swift breeze. Hendo's ability to recover instantly is legendary, yet vitor stopped him after the TRT ban. Would Hendo have recovered after fedor dropped him, without TRT?
Do we have any other examples of people who admittedly took special "proteins", or were highly suspected of using, then when forced to clean up, no longer took a punch like they used to?
Hendo was on TRT when he fought Vitor, wasnt he? Bigfoot had been ko'd by Cormier, dropped by Mike Kyle, murdered dead by Cain twice, all while on TRT.
If anything, the battle with Hunt (where he got dropped once or twice and was about to be finished when saved by the ref to check a cut) probably finished off what's left of his chin, and the Andrei fight showed that. Then you factor in the shots he has likely taken in training between the hunt war, and the andrei ko, and you have Mir catching him a punch he never saw coming....done.
Overeem usually gets ko'd after gassing after exploding on somebody, and coming close to finishing the fight, but not getting the W. His defense has gone to complete shit as well. In K1 he liked to hide behind those big ass gloves.
These are also all fighters with a shit load of wear and tear already.
I want some of these magic hormones, according to mist people on this site they do everything from make to invincible to making your dick bigger. I have been on try for quote sometime and honestly there isn't a huge difference. If you do it correctly you are only putting your hormones back to a normal level.
All things being equal having a larger and rounder head is going to help your chin along with having a bigger neck/traps.
TzTinkle - All things being equal having a larger and rounder head is going to help your chin along with having a bigger neck/traps.If you are doing prescribed trt at proper dosages you won't have a bigger head, traps or shoulders.