Proper Neurotransmitter Production

Cofactors needed for proper neurotransmitter production

The generic protocol developed for management of neurotransmitter dysfunction relating to the catecholamine system and/or serotonin system was developed by Marty Hinz, MD and involves the use of the amino acids tyrosine, 5-HTP, and cysteine along with the cofactors needed for neurotransmitter synthesis, including vitamin C, vitamin B6, calcium, selenium and folic acid. Results do not appear to be dependent on taking the amino acids with or without food; however, taking amino acids on an empty stomach should improve absorption and uptake and is therefore preferred.


The use of cysteine, selenium and folic acid are used to prevent depletion of the methionine-homocysteine cycle by L-dopa (and presumably by L-tyrosine as it is the immediate precursor of L-dopa). Administration of L-dopa leads to depletion of S-adenosyl-methionine (SAMe) which acts as a methyl donor in many important reactions and is part of the methionine-homocysteine cycle (which, amongst other things, helps maintain healthy homocysteine levels).

In addition, proper levels of SAMe are needed in order for norepinephrine to be converted into epinephrine. Therefore, long-term use of L-dopa without proper administration of cysteine and folic acid can lead to the depletion of epinephrineas well as a loss of SAMe. (2)

Therefore all people taking L-dopa and/or L-tyrosine need to be supplemented with adequate levels of sulfur amino acids to prevent depletion of the methionine-homocysteine cycle, depletion of glutathione, depletion of epinephrine, and the other components dependent on the methionine-homocysteine cycle. While administration of any of the sulfur amino acids in the cycle is adequate if the dosing is high enough, cysteine is chosen because it is the most cost effective.


Selenium needs to be administered with cysteine to prevent cysteine (or any sulfur amino acids) from creating an environment that contributes to central nervous system neurotoxicity from methylmercury.

Methylmercury is formed in the body if body stores of mercury come into contact with a methyl donor, such as SAMe or cysteine. Methylmercury is a much more toxic and dangerous substances than elemental mercury, as it can cross the blood-brain-barrier and studies have shown that administration of sulfur-containing amino acids can potentially facilitate the concentration of methylmercury in the brain. (5) However, selenium irreversibly binds to methylmercury in the central nervous system rendering the methylmercury biologically inactive and non-toxic.(6) Therefore, by providing the body with sufficient selenium along with adequate sulfur amino acids, such as cysteine, the potential danger of methylmercury exposure is avoided.

Folic acid

Folic acid is required in order to provide optimal function of the folic acid cycle which keeps the methionine-homocysteine cycle functioning properly. Folic acid also plays a vital role in keeping homocysteine levels in check.

High levels of homocysteine can increase the risk of cardiovascular disease, Alzheimer’s disease and bone fracture. It can take 3 to 6 months for high homocysteine levels to return to normal once proper levels of folic acid, B6 and B12 are established.  As noted previously, without proper administration of amino acids of the methionine-homocysteine cycle epinephrine is depleted. It appears to be no coincidence that it can take 3 to 6 months for epinephrine levels to return to normal, a fact that appears to parallel proper balance in the methionine-homocysteine cycle with corresponding homocysteine improvement.



  1. I would like to know who does this treatments describe above.
    I need this therapy for myself.

    • Hi Albert – thanks for your question.

      We have worked with amino acid therapy for over 16 years; however, there are many providers throughout the country that do as well. To get started, I would suggest you first contact NeuroSupport to see if there is a provider in your area:; if not, please contact us and set up an initial phone/skype consultation and we’ll be happy to work with you.


      Dr. Chad

  2. I wondered if there is an application here for Parkinson’s disease?
    Have you read anything that would suggested that the diet you are recommending might produce dopamine in a quantity high enough to make a difference in their quality of life?
    As you, unlike mood and ADHD Parkinson’s is progressive and displays has both physical and mental symptoms.
    It might be empowering for folks if they felt their diet might play a part, however small, in their performance. Obviously this would be in addition to whatever dopamine replacement drug they were currently using.
    Just curious.

    • Hi Karen,

      Thanks for the comment; there is, in fact applicability to those with Parkinson’s disease. In fact, we have designed another website around it to provide more information:

      While diet alone has not been shown to make a significant difference in and of itself, we certainly use dietary changes in combination with other therapies to try and manage the underlying imbalances that can lead to Parkinson’s.

      I like the way you are thinking!


      Dr. Chad

      • Is it normal during this protocol to see high levels of Arginine on a NutrEval test??

        • Hi Greg,

          I do not know of any reason that properly directed amino acid therapy would impact arginine levels on a NutrEval test.

          Hope this helps!

          Dr. Chad

  3. I have had insomnia for years, managed with meds. In the past few months, I’ve developed abnormal anxiety to the point I had to leave my job. It adds to the insomnia and meds are only minimally effective.
    In the past, I’ve been on one antidepressant after the other. I also had a cocaine addiction in the 1990s which I came out of.
    I used to sleep like a baby. Now I can not shut down without something.
    I want my sleep and zest for life back.
    Does it sound like I have a neurotransmitter imbalance? I know I’d need to be tested.
    Can this be cured?

    • Hi Cathy,

      Thanks for contacting us. Based on the information you’ve provided, it is likely that at least some of your symptoms are due to neurotransmitter imbalance and amino acid therapy may provide you the relief you are looking for. Please contact us to set up an initial appointment if you’d like to get started.


      Dr. Chad

  4. Hi Dr.Chad My wife,a46 ys.old lady,had a diplopia with a history of diabets 10 mots.ago,diagnosed as MS deasis by Neurologist,via MRI,but not through CSF test.A mass on the top of her brest ,4 mnts. ago ,found as carcinoma made us to perform partially mastectomy . Now she has had 4 of 8 trials of chemotherapy,and then she will have 25 courses of Radiotherapy.She has some problems with “sleep” ,”recognition”,anxiety”,.. .So I have two requests.fist:Is your Am.Asid.THRP.Useful for him?secound:How c we can achive your servises,while you know we live in Tehran/Iran?

    • Thanks for your inquiry; amino acid therapy may be able to help with the sleep and anxiety. Unfortunately, we are not currently accepting additional international clients and I am not aware of any other providers that are. However, you can contact NeuroSupport to see if they have any providers that may be able to help:

      Good luck!


      Dr. Chad


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