Brewer's Yeast - NOT De-Bittered !

I've been taking Brewer's Yeast for 2 years and it has worked wonders
for my acne which i find it's basically due to B5 components.
Recently i run out of brewer's yeast brand i used to buy (the
laboratory that used to manufactured it simply dissappeared and i
can't find it anymore).So i decided to try GNC Brewer's Yeast and now
i find i don't get the same results i used to get with my previous
Brewer's Yeast (same serving).I've been doing some research and i
figure out there's two kind od brewer's yeast:

- The one with Bitter Taste which according to some previous postings
in here states that has a good result with acne treatment
- The De-Bittered Brewer's Yeast which apparently does't work so
effectively against acne.

On GNC website i found they offer Brewer's Yeast (The-bittered one)

Question: Can anyone recommend me a NOT De-Bittered Brewer's Yeast
brand? and if possible what on-line store offers it?

Thank you


Thesonicboy