L-Tyrosine supplements


I was dx some 18 months ago. 8 months ago, my nutricionist (which is also a GP) suggested I take L-Tyrosine supplements (1,000 mg/day every morning, with a glass of water 20 mins before eating/drinking any foods/juices, to ensure it's properly absorbed). His logic was that Tyrosine is supposed to boost mental alertness and energy (I complained of persistent tiredness) and that my tests showed I had low levels of Homovanillic acid (which suggests low levels of dopamine - unsurprising given PD). I've been taking these supplements and feel it does help with the alertness and energy and so far I feel no negative side effects at all. My only concern is that tyrosine is the main precursor to l-dopa (i.e., the main ingredient our brains use to create l-dopa), so I wonder if taking these supplements is a disguised way to take l-dopa (which I'm not taking yet). In addition to these Tyrosine supplements, I'm currently taking Azilect, CoQ10, vit C, Vit E, plus other stuff my tests showed I was low on (vit D, iodine, magnesium). I'm also taking some stuff which is supposed to help with inflammation (there are some hypothesis of inflammation being linked to PD and my tests show a few signs of inflammation). I've also adapted my diet and am doing some regular sports. So far, my PD symptoms remain very light and don't seem to be progressing much (or even at all), though I have no idea if any of this stuff I'm doing is having any impact or if it's just the way it goes anyway.

I've discussed the Tyrosine supplements with the 2 neurologists that I see. None had any clear view on any possible impact of taking Tyrosine supplements for PD. The one that seemed most informed about it said she knew of no studies showing that Tyrosine supplements could impact PD in any clear way, and clearly of no long-term studies. She was even unsure if Tyrosine, taken in supplements, would even make it to one's brain. She didn't know either of anything that could count as a serious drawbacks of taking them. Her only words of caution were: (a) over-the-counter supplements (like Tyrosine's) are somewhat riskier because they are subject to less stringent quality controls than prescription stuff, and (b) taking stuff that hasn't been tried and tested for PD may always turn out to have negative consequences. The other neurologist was even less helpful.

I personally have no idea if my Tyrosine supplements really have any impact on my PD. I can't really feel any difference in my PD symptoms after taking it. They don't get noticeably better after I take it, nor worsen when I don't take them (and sometimes I don't take them for a few days)... but my PD symptoms are very light and somewhat intermittent, so it's difficult for me to really tell.

So, I was wondering if anyone knows anything more about Tyrosine supplements or has had any experience with it.

Thanks in advance,

i might be wrong but l-tyrosine might be dangerous when taken with azilect. it is not recommended when taking mao-a inhibitors. azilect is a mao-b inhibitor mainly but does have some effect on mao-a especially if you take too many. it might be a small risk but personally i wouldn't take both.

l-tyrosine is regulated by tyrosine hydroxylase which i think means there is a maximum amount that is converted to levadopa which is why we are given levadopa not l-tyrosine.
Hi turnip,

Thanks for mentioning that! I indeed read that Azilect at high dosages (above around 2 mg per day) starts to inhibit MAO-A and that MAO-A inhibition combined with high tyrosine can cause hypertensive crisis (which in turn can lead to pretty bad stuff). I confess I have felt a bit more reassured by the facts that: (1) I'm "only" taking 1 mg of Azilect/day; (2) my tyrosine dosage doesn't seem very high; and (3) I normally have my pressure on the low side... but having said all that you do make me think how wise this combination really is (plus that I haven't really checked my blood pressure in a while)...

Cheers and thanks for the helpful word of caution,

Just thought I'd add my own word of caution about Tyrosine. I also read in a number of places that you shouldn't take Tyrosine together with l-dopa meds. From what I understood, this is because they compete with each other for absorption by our brains, and so, by taking them together we would render one of them (or both) less effective. I didn't read anything about combining them being dangerous (but this isn't a guarantee that it isn't, of course).

On the more positive side I did find a couple of old studies that speak for the virtues of Tyrosine for PD: One (from 1982)concludes that "l-tyrosine administration can increase dopamine turnover in patients with disorders in which physicians wish to enhance dopaminergic neurotransmission" (http://www.ncbi.nlm.nih.gov/pubmed/6175872). The other (from 1989) concludes that "For some patients, 3 years of L-tyrosine treatment was followed by better clinical results and many fewer side effects than with L-DOPA or dopamine agonists." (http://www.ncbi.nlm.nih.gov/pubmed/2502304).

However these studies are 20-30 years old, which makes me wonder that if Tyrosine was so great why isn't everobody using it today? And also the 1989 study only involved a tiny number of PD patients. So, wondering if anyone has any more info that could shed some light in this (e.g., any more recent studies?).

Turnip: Your point that there is a mechanism that limits the maximum amount of tyrosine that can converted to levadopa seems totally true and maybe is the real reason why L-dopa is today the medication of choice... but on the other hand, I'm tempted to speculate that precisely that aspect could make Tyrosine have some beneficial long-term advantages. Intuitively, I quite like the idea that there's a mechanism that prevents my neurons from overworking too much and thus protect them from any possible situation of "neuron burn-out" we might inadvertently induce by taking meds that get them to work harder to create more dopamine. I know this line of thinking is pure speculation from my side, as I've never seen this notion of "neuron burn-out" discussed or addressed anywhere, but I confess it does cross my mind, and so would be interested to know any view you (or any others) may have on it.

Cheers to all,


I was dx some 10 years ago and have been on 250mg Madopar twice daily for 2.5 years. I've found that any dopamine taken after 3pm doesn't work. Like others I had difficulty in sleeping - my brain just wouldn't slow down. However, that changed when I took L-tyrosine at bedtime. BLISS!:smile:It appears to work like melatonin is said to do. I've stopped 3 times and have reverted back to fitful sleep in a week, so I now don't go to bed without taking 500mg L-tyrosine.

The only 'sideeffect' is that I no longer feel the cold so much. I've felt cold for > 30+ years with the last 10 winters being truely miserable until I started L-tyrosine in spring 2011

Yet, I cannot find any reports anywhere that this should work as a sleepaid. Am I unique?