Can L-tyrosine replace L-dopa?

[Gioc]

I tried it yesterday evening and it would seem that it does so to a small extent. Has anyone tried it?

[pvw2]

Not the answer you want to here, but probably the best we have in the following discussion. You should remember this one.

healthunlocked.com/parkinso...

[Gioc in reply to pvw2]

Oh yeah! in fact I was intrigued right there and I had bought it on the web.

Yesterday I tried it and it seems to have an effect similar to L dopa but to a lesser extent. It would seem that apart from b-bar here

healthunlocked.com/parkinso... no other has experimented.

have you ever tried it?

[pvw2 in reply to Gioc]

I don't even take L/C only inhibitors.

[Parkinsonjisung]

The fact that ldopa works and tyrosine doesn't has always intrigued me. The common explanation that I've read is that the enzyme tyrosine hydroxylase is massively reduced in people with Parkinson so it cant be converted into ldopa. However I've seen very little research on why this is. Ldopa is converted by addc into dopamine but addc is also reduced. I've never understood why tyrosine supplements wouldn't at least help a small bit. For most people it has no effect it seems.

Be careful if you take them together as they travel on the same pathway and could reduce effectiveness of ldopa.

[silvestrov]

The following study is the most recent clinical trial on tyrosine and PD (to my knowledge).

Effects of Tyrosine on Parkinson's Disease: A Randomized, Double‐Blind, Placebo‐Controlled Trial

ncbi.nlm.nih.gov/pmc/articl...

The aim was to study the effect on orthostatic hypotension (OH), a common PD symptom, and it was halted after one week - tyrosine had no effect on OH. Hardly a long term trial.

Plus, from the above article: "Reduced levels of tyrosine have been shown after administration of l‐dopa." L-dopa/Sinemet can cause a tyrosine deficiency.

Also, the 'Hinz' protocol uses tyrosine in conjunction with mucuna pruriens/levodopa to treat PD:

Amino acid management of Parkinson’s disease: a case study

ncbi.nlm.nih.gov/pmc/articl...

Here is the abstract of a (small) older tyrosine PD trial: ncbi.nlm.nih.gov/pubmed/250...

Both levodopa and tyrosine are more effective when consumed with vitamin C. In this study 200 mg of ascorbic acid improves the pharmacokinetics of levodopa:

The Effect of Ascorbic Acid on the Pharmacokinetics of Levodopa in Elderly Patients with Parkinson Disease

researchgate.net/publicatio...

From 1956:

"It has been known for a number of years that vitamin C is necessary for the normal metabolism of tyrosine." adc.bmj.com/content/archdis...

I have corresponded with a man who has atypical parkinson's and takes tyrosine with his sinemet and he says he feels better when taking it. Sure it may be a placebo effect but it is worth looking into either as monotherapy or in conjunction with some form of levodopa.

Like any amino acid/drug etc... tyrosine has contraindications including: high blood pressure, melanoma, weak heart, hyperactive thyroid gland, MAO-b inhibitors, bipolar condition or schizophrenia.

[sharoncrayn in reply to silvestrov]

"Like any amino acid/drug etc... tyrosine has contraindications including: high blood pressure, melanoma, weak heart, hyperactive thyroid gland, MAO-b inhibitors, bipolar condition or schizophrenia."

Where did you get this erroneous info from? Or is this your interpretation? For example, melanoma studies (cell microbiology types or animals like hamsters and mice) simply infer the possibility of increased pigmentation with excessive(!) doses L-Tyrosine in humans.

Fact #1 --- relevant to PD patients taking both L-Tyrosine and L-Dopa is that these amino acids compete with each other across the BBB, which is normal for single amino acids, so separate their intake by at least 1 hour to maximize the impact of L-Dopa.

Fact #2 --- from retrospective cohort studies... these previous studies have demonstrated relatively well a range from two-fold to seven-fold increased risk for melanoma among patients with Parkinson disease.

Question?: did PD patients with melanoma have an excessive intake of L-Tyrosine to create their melanoma condition? I seriously doubt it.

Sharon

[LAJ12345]

It’s in Restore Gold, amongst other things. My husband takes it as one of many. Something is helping!

[bepo]

Mucuna is a natural form of L-Dopa. My husband takes mucuna with tyrosine and 5-htp. We have followed the Hinz protocol for 5 years. My husband still takes the protocol along with HDT.

[pdkid in reply to bepo]

does he take the mucuna, tyrosine and 5-htp all at the same time? or spread out separately? does he also take the hdt at the same time? thanks!

[bepo in reply to pdkid]

He takes the mucuna capsules @ 650 mg.,along with tyrosine and 5-htp all at the same time, 5x a day. He takes the B1 separately.

[pdkid in reply to bepo]

what % extract is that? the 40? thanks a lot!

[bepo in reply to pdkid]

40% mucuna capsules from Barlowe's herbs. He has used that for years.

[pdkid in reply to bepo]

hello again... wondering what tyrosine dose he takes each time? we are incorporating it into my dad's supplement regime and i read that 2grams was the max upper limit... but maybe its different for pwp...? thank you for any insight!

[bepo in reply to pdkid]

We balance it with the 5-Htp. He takes 950mg 5 times a day. We use vitacost

[pdkid in reply to bepo]

O wow, thats much higher than the upper limit! Ok I guess it must be different in order to get a therapeutic effect for pwp. Thanks!

[bassofspades]

Gio, it was from you that I learned that dopamine synthesis is a process that goes from a to b to c, etc, to z, and when you administer L Dopa you cut right from a to z. Somewhere between a and z theres a bottleneck in the process.

[Jandeb]

Some good points from some smart folks. One thing to consider is that most PD patients are 55+ and as such amino acids can get catabolized by digestive and absorptive tissue where the amino group and carbon skeletons get scavenged to make other molecules. In other words consuming say 100 mg of tyrosine may not actually deliver 100mg. Taking acetyltyrosine will deliver more in that it is not easily catabolized.

[sharoncrayn in reply to Jandeb]

Actual research suggest L-Tyrosine and Acetyl L- Tyrosine have almost the same absorption rates contrary to some popular web site articles.

"catabolized" = degraded, but splitting hairs here with the chem text books.

degraded amino acids become ketogenic(!) or glucogenic amino acids.

all amino acids must be broken down in the liver (principally, but almost all parts of the human system take part) where the separation of the amino from the carbon skeleton takes place.

Catabolism, if you chose to use that term, requires (or strongly suggests) glucose deprivations i.e. low, very low, or non-existent intake of simple sugars and complex carbohydrates. Therefore, we could surmise that perhaps the efficacious absorption of any amino acid (including L-Dopa) relates more to diet than age or disease condition (PD), or your gut microbiome efficiency (Yes, even your microbiome!). Besides, your brain requires sufficient glycogen to function efficiently.

Something to think about.

Sharon

[bepo in reply to sharoncrayn]

Very interesting!

[MarionP]

I think you would find that your L Tyrosine oral dose is less concentrated than a dose of a drug engineered to deliver a clinically relevant amount of LDopa. Further, Tyrosine and LDopa are not equivalent as the former is precursor of internally manufactured dopamine, a dose of any form of dopamine will not cross the blood brain barrier, whereas tyrosine will cross the barrier and thus be available for manufacture of dopamine to the extent that the dopamine producing cells are able to produce it...and tyrosine is able to get into the brain whereas dopamine cannot...and a lack of such dopamine producing cells in the particular section of brain called substanta nigra is the principle agreed proximate cause of PD in the first place.

Actually tyrosine is the first ingredient in the process that manufactures all three of the so called "catacholamines," of which dopamine is one...the other two being epinephrine and norepinephrine. So consider that while you might be making some dopamine, you might also be making some amounts of what are basically amphetamines as well.

But further consider that since dopamine will not cross the BBB, dopamine, whether in a L-Dopa drug form or mucuna or cooked fava beans or some other form of dopamine, such externally dosed dopamine is not available inside (or "behind") the blood brain barrier, thus it is available to nerve circuits outside of the brain, i.e., the "extrapyramidal" motor circuits yes, but not circuits that are behind the BBB (known as CNS, central nerve system, i.e., brain and spine nerves). This means that with Tyrosine, one can get the precursor to dopamine into the brain, where it can do some good there for problems that arise in neurotransmission in the brain (some of which surely extend eventually into pyramidal muscle functioning), but tyrosine is still only useful to the extent that you have a relevent dose that makes it into the brain, and then only useful to dopamine cells that are present and healthy enough to produce dopamine beyond what they already produce now. Tyrosine is also going to be readily useful to other regions of the body, outside the brain, that produce and use dopamine.

Also I think that there is a "rate-limiting" co-factor that is required in sufficient amount to produce dopamine from tyrosine, but at the moment I don't remember what it is. Like yeast is to baking powder...if you don't have enough yeast, the bread won't rise, and really isn't much like bread no matter how much baking powder you put.

So that is an interesting idea, but also a bit of a stretch to meet all these conditions to benefit. Worth trying however, and see how it goes in your individual case.

I should hesitate to expect too much effect compared to an actual drug, and effects to be somewhat gradual or suble and depend on the nature and extent of the individual's PD, but if perhaps some effect is better than none, go for it and experiment, oral tyrosine is not harmful that I know of (assuming the specific supplement in your hand actually contains it in sufficient quantity and purity and is absorbable, and any fillers and other ingredients are not harmful, which is I think a fairly large assumption with each and every bottle).

If it helps, then it helps!

[sharoncrayn in reply to MarionP]

" dopamine, whether in a L-Dopa drug form or mucuna or cooked fava beans or some other form of dopamine, such externally dosed dopamine is not available inside (or "behind") the blood brain barrier, thus it is available to nerve circuits outside of the brain, i.e., the "extrapyramidal" motor circuits yes, but not circuits that are behind the BBB."

[MarionP in reply to sharoncrayn]

Tyrosine is not dopamine. Tyrosine is a precursor that does clear the BBB barrier for manufacture behind the barrier...if your cells are producing any. Biochemist, experienced in PD, and yet you sarcastically bait me for clinical questions (in which YOU are the amateur you so heartily name-call others) while not knowing your own science? Of course, if you can't apologise when wrong, especially if the putative goal is to correctly inform people, that looks more a personal problem...and there's a spot in the book for that too. Never met a genuine scientist who never made a mistake...for one must ask in such cases how effectively they were actually able to learn. At least clinicians have a specific professional ethic, as well as peer training, explicitly intending to prevent one's errors to be passed onto people vulnerable to the effects of the error. People's trust is nothing to take lightly, or subject to one's personal needs, it tends to be incompatible with one's self-indulgences. Those who can't supervise themselves, or worse, won't or are untrained in that skill, are better off "sticking to their knitting," or at least giving up purporting to being someone to rely upon.