As far as powerful fat burner? No, T-Rex is the best.
I saved this post of mine & will KINDLY report for you, since it addresses some questions you're asking...
"The T-Rex is Very strong. The combo of yohimbine hcl and synephrine is known to cause Nausea / Queasiness, so it is recommnded that you NOT take the dose on an empty stomach (i.e. the fiber banana has help prevent this) esp. if it's your 1st time.
Start with One Cap and see how you feel. You can do One cap 2 X a day & go from there. BUT NOT after 4 pm (some say 3pm). You may be unable to sleep if you take it later in the day.
There were times I was

in the parking lot before my w/o and 20 minutes later I was pumped ... EveryBODY is different so try it out and see how it works for you

"
Now, T-Rex speeds up fat loss while you use it. When you stop using it your body returns to the same state it was in when you started. So it doesn't make it any harder to lose fat when you stop than it was before you started.
The make up of CB & T-REX is VERY VERY similar ... other than the yohimbine hcl and synephrine (NOT IN CB), T-Rex has other ingredients for 'focus' & 'clarity' ...
I have health issues too

I would call anafit or PM Ulter & specifically tell him what the issue is & whether there are any sides, etc. that may affect YOUR specific issue ... or you can PM me & I will be happy to discuss things with you in more detail