Stimulants L-Tyrosine antagonises Amp's affect?

[CFC]

Was just doing some reading of studies, and came across this one on mice which shows that, when supplemented with dietary Tyrosine, lower doses of d-Amphetamine (75mg & 100mg @ 100kg bodyweight equivalent) caused a significant reduction in locomotor activity (basically a measure of its effect) compared to those not supplemented with Tyrosine. Conversely, with higher doses of d-Amp (300mg), an above average locomotor activity was recorded. At both higher and lower doses of d-Amp, Tyrosine significantly reduced levels of norepinephrine and dopamine compared to non-Tyrosine supplemented mice.

The study is a bit old now (1990), I wondered if things had moved on, as I had taken to assuming that Tyrosine was generally assumed to increase output of DA and NE irrespective of Amp dose.

http://www.ncbi.nlm.nih.gov/pubmed/2080188

 

[sekio]

Tyrosine is naturally present in the diet, it's not anything that you should worry about.

 

[MichelJacques]

Not up for going through the paper at the moment, but what I gleaned from the abstract mirrors my personal experience. I've tried supplementing 1-2g of L-tyrosine before taking low doses of both methylphenidate and amphetamines (5mg for either), and found that I end up not feeling the ritalin or adderall at all. Had assumed the extra dopamine precursor would increase the effect of low dose either drug, but this apparently is not the case. I've only tried this a handful of times, but my experience does corroborate the finding that L-tyrosine attenuates low dose amphetamine.

 

[CFC]

Tyrosine is naturally present in the diet, it's not anything that you should worry about.

I didn't raise this out of concern lol. My interest is academic.

 

[CFC]

Not up for going through the paper at the moment, but what I gleaned from the abstract mirrors my personal experience. I've tried supplementing 1-2g of L-tyrosine before taking low doses of both methylphenidate and amphetamines (5mg for either), and found that I end up not feeling the ritalin or adderall at all. Had assumed the extra dopamine precursor would increase the effect of low dose either drug, but this apparently is not the case. I've only tried this a handful of times, but my experience does corroborate the finding that L-tyrosine attenuates low dose amphetamine.

That's interesting. I noticed something similar with Tyrosine supplementation, but of course it seemed completely counterintuitive and I disregarded it until I read this. I wonder if other users have experiences a similar effect.

 

[bluespeed]

I consumed 2g l-tyrosine along with 1g l-citrulline before doing amph or meth or 4-fa (all 3 in different days ofc) a couple times, always moderate to high doses though. The high always felt exactly the same, if not even more stimulating except there was less slightly vasoconstriction. Which was why I tried those supplements in the first place because I tend to suffer from really cold hands and feet on every stim.
It would be interesting to combine these supplements with low doses of speed, I never take low doses of amphetamines though lol.

 

[CFC]

I consumed 2g l-tyrosine along with 1g l-citrulline before doing amph or meth or 4-fa (all 3 in different days ofc) a couple times, always moderate to high doses though. The high always felt exactly the same, if not even more stimulating except there was less slightly vasoconstriction. Which was why I tried those supplements in the first place because I tend to suffer from really cold hands and feet on every stim.
It would be interesting to combine these supplements with low doses of speed, I never take low doses of amphetamines though lol.

Thanks for that info. Maybe try low dose a few times and see if you can sense any subjective reduction in effect? I've only ever used low doses, but must admit I'll probably avoid testing the high-dose theory for now lol.