I went toe to toe with a deathclaw, I used no chems, after the fight, my health was at 73%. Probably because my eyes were open (refer to my avatar) and I had a DT of 31.
Did you use VATS with that paralyzing palm perk?
Cause I never use VATS, always play on Hard or Very Hard and never wear any armor with DT of 21+.
That's probably why I needed the extra buff.
Still, doesn't hurt to use them, every little bit helps.