L-Tyrosine is a great supplement. It is the amino acid precursor to the energizing neurotransmitter norepinephrine. I've read that most stimulants (including caffeine) can deplete norepinephrine over time. So tyrosine helps to restore this deficiency. However, to be effective some guidelines need to be followed. First, it needs to be taken on an EMPTY stomach. Any other aminos ingested will compete with tyrosine when crossing the blood/brain barrier, leading to a much diminished effect. Any carbohydrates ingested will promote an insulin response. With the exception of tryptophan, insulin sweeps all other aminos OUT of your blood stream (including tyrosine). Again, leading to a diminished effect. So it's best to take tyrosine at least 1.5 hours AFTER your last meal, and 1 hour BEFORE your next meal. Second, research seems to show that tyrosine's bioavailability isn't the greatest. So a larger dose is needed to offset this problem. For me, 3-4 grams was needed to feel it's energizing effects.(Don't take after 2:00 p.m., or you might have trouble sleeping). On a side note, tyrosine is also involved with melanin production(skin pigmentation). When I upped the dose to 4 grams/day, I noticed that the moles on arms darkened up a bit(within 1-2 weeks). I don't really care about that effect in particular. But it showed me in another way that a 4 gram dose was needed for an adequate amount of tyrosine to be absorbed from the digestive tract.--So overall, I feel this a great supplement to add to your muscle/energy production arsenal, but only when using the above mentioned guidelines. |
[5 of 5 Stars!]
