Posted by 3 Beer Effect on March 23, 2002, at 23:00:07
A few months ago I read on Pubmed about a study that said that l-phenylalnine supplementation inhibits either tyrosine hydroxylase (the thing that turns l-tyrosine into l-dopa) or the thing that turns l-dopa into dopamine (aromatic hydroxylase or something like that. Not sure which one it inhibits? Does anyone know about l-phenylalanine inhibiting dopamine production?
L-phenylalanine seemed like a good thing to take since unlike most amino acids it actually crosses the blood brain barrier & seemed to have some slight amphetamine like effect after 2 weeks of 1500 mg/morning on an empty stomach (Twinlab w/o vitamin B6 was the only brand that worked for me, country life w/ B6 had no effect). But I stopped taking it after reading the dopamine inhibition article & now I can't find the article I read (in Pubmed).
Also, why do many l-phenylalanine supplements contain vitamin B6 (pyridoxine) when vitamin B6 completely nulls the dopamine enhancing effects of levodopa?
I used to take l-tyrosine but stopped since it doesn't cross the blood brain barrier & can only be transported to the brain by a carrier that is already saturated by a normal diet. I also noticed no effects & it seemed a waste of time/money.
But I wonder if tyrosine or phenylalanine supplementation would be a good idea if you were taking Dexedrine or Adderall everyday & thus constantly depleting your dopamine stores or perhaps like many supplements found at the health food store it is a waste of money?
poster:3 Beer Effect
thread:99751
URL: http://www.dr-bob.org/babble/20020322/msgs/99751.html