Parkinson's Movement
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Dr. Costantini sent the following article this morning for the HU forum members to read regarding HDT overdosing since it is currently a very popular subject.


Effects of Overdose of High-Dose Thiamine



We treat Parkinson’s disease with high dose thiamine in

addition to the classic therapy since 2012. On this topic, we

published three studies carried out with Italian patients [1-3]. The

treatment consisted in performing 2-3 intramuscular injections of

100mg of thiamine per week. The highest dosage was reserved to

patients whose disease severity was the greater, long past onset, and

patients whose weight was more than 90kg. We also treated patients

on anticoagulants. In this case, the thiamine was administrated

orally (tablets). We noticed that in order to obtain comparable

results of the intramuscular therapy with the oral therapy we

needed to administrate a dose of thiamine 140 times when treated

with tablets or capsules (personal data, not published). In other

words, in order to obtain the same clinical effect of 1 intramuscular

injection of 100mg of thiamine once a week, it was necessary to

administrate 14 grams of thiamine orally per week, or 2 grams per

day. This dosage, when appropriate for the patient, has always been

well tolerated and we did not observe collateral effects.

At the end of 2015, our patient’s pool was considerable, and we

began to notice that some patient, after the first two weeks on high

dose thiamine protocol, would show an initial general improvement

followed by a worsening of the original symptoms. We started to

think that the cause could be attributed to an excessive dose of

thiamine for that specific patient, since we have observed a similar

behavior in other diseases [4-6]. Suspending the thiamine protocol

for a week led to the regression of the worsening of symptoms. The

therapy would then be restarted at halved dosage, which could

be further adjusted to reach the correct dosage for the patient

and obtain a consistent decrease of the symptoms without any

collateral effect. We deem that the appearance of the symptoms

of thiamine overdose could have an incidence of about 1% of the

patients treated with 200-300mg of thiamine per week or with

the corresponding oral doses. We also observed a prevalence of

thiamine overdose manifestation in newly diagnosed patients, or

in patients whose symptoms are mild or who have a small body

mass. Over the past months, we began to treat a number of patients

of Anglo-Saxon and African origin. Initially we started the therapy

with the same schedule used for patients visited in Italy and

described in our studies. The vast majority of the patients showed

quite soon symptoms attributable to overdose of thiamine, even

the same day of the first thiamine administration. Some patients

showed, in addition to a general feeling of discomfort, unrest and

an overall worsening of the symptoms of Parkinson’s disease, also

a medium intensity migraine. Such a symptomatology regressed

after a few days after the high dose of thiamine was suspended and

consequently restarted with halved doses. In other words, these

patients have been observed to require, on average, lower doses

than those of Italian patients in order to return the same favorable

effects on the symptoms. Other ethnicities could be more or less

sensitive to the therapy with high dose thiamine. In light of the

above, we recommend that colleagues and practitioners begin the

treatment with patients of ethnicity other than Italian with doses

that are half of what we published previously with reference to

the case studies we observed directly. The correct dose, in our

experience, is the one that improves the symptoms of Parkinson’s

disease and improves the sense of balance bringing the score of the

pull-test close to normal, as opposed to its altered state due to the


Conflicts of Interests

On behalf of all authors, the corresponding author states that

there is no conflict of interest..


1. Costantini A, Fancellu R (2016) An open-label pilot study with high-dose

thiamine in Parkinson’s disease. Neural Regen Res 11(3): 406-407.

2. Costantini A, Pala MI, Grossi E, Mondonico S, Cardelli LE, et al. (2015)

Long-term treatment with high-dose thiamine in Parkinson disease: An

Open-Label Pilot Study. J Altern Complement Med 21(12): 740-747.

3. Costantini A, Pala MI, Compagnoni L, Colangeli M (2013) High-dose

thiamine as initial treatment for Parkinson’s disease. BMJ Case Rep. pii:


4. Costantini A, Pala MI (2013) Thiamine and fatigue in inflammatory

bowel diseases: An open-label pilot study. J Altern Complement Med

19(8): 704-708.

5. Costantini A, Tiberi M, Zarletti G, Pala MI, Trevi E (2018) Oral high-dose

thiamine improves the symptoms of chronic cluster headache. Case

Reports in Neurological Medicine. Article ID 3901619.

Copyright © All rights are reserved by Antonio Costantini. 1/2

Volume - 4 Issue - 1

Antonio Costantini1* and Roberto Fancellu2


Department of Neurological Rehabilitation, School of Physiotherapy, Italy


Neurology Unit, Italy

*Corresponding author: Antonio Costantini, Department of Neurological Rehabilitation, Italy

Submission: December 03, 2018; Published: December 06, 2018

6. Costantini A, Laureti T, Pala MI, Colangeli M, Cavalieri S, et al. (2016)

Long-term treatment with thiamine as possible medical therapy for

Friedreich ataxia. J Neurol 263(11): 2170-2178.

26 Replies

Thanks for this. I’m currently on 2gms and doing well. Has really made a difference to my rigidity and restlessness but my slowness is worsening abit so may try cutting down to 1gm. Age 52, female, 64kg, dx 3yrs,

are u also on levadpa?

No not on any PD meds yet. Only HDT

HiddenThis reply has been deleted
in reply to Hidden

I'm not sure why the link isn't working, but the written part below the link shows the entire link that Dr. C sent this morning!



Technically you cannot share a password protected link like email here. It’s impossible.

If you want to exhibit its originality you can make a screenshot from Dr Costantini’s email and add it to this post as a thumbnail.


in reply to Kia17

Yes, I will remove it, as all of what Dr. C wanted to tell the forum members is already in the post. I was hoping the link would take you to the actual article he wrote, but it is all there in the post already! I will remove the link. Thank you, Kia!


in reply to Hidden

Thank you for sharing Art


in reply to Hidden

It’s helpful. Thanks Art.


Thank you for posting this, it'll be of great help not only for those already on HDT but also for those considering starting so as to try and avoid an initial excessive dose. I guess the more people who share their experiences with HDT the wider knowledge of it will emerge, which will benefit all of us. Thanks again.

Thanks Art. Useful.

December 1st I came to the same conclusion. From all the reports, posts and comments about dose size I reduced mine from 4g to 2g Pd.

in reply to RoyProp

Today Dr. Costantini recommended I continue with 4 g daily and continue C/L 50-200. I should never get dyskinisia

in reply to RoyProp


It seemed that you were doing very well at 4 grams/day for a fairly good period of time. What made you want to go down to 2 grams/day?


in reply to Hidden

I am not going to reduce. Today Doc C said dont

in reply to RoyProp

Was there a reason to reduce or just further experiment on your part?

in reply to Hidden

So many people were going low dose I thought I would try.

Seems valid for almost all of us.. In my case when I started months ago my dose was 4g. Now after regular consulting with Dr C, I am already on only 500mg..

Thank you, Art. Per consultation with Dr. C, I am suspending THCL for one week and then halving the dosage from 2 gms per day to 1 gm per day. Weight: 120; Ht: 5'6"; Dx'd: 5 years approx.

Thanks, Art! My husband is on 100mgx2/week from 300mg as recommended by Dr. C. He started 9 days ago. I still think it's a little higher dose than I believe he should be on, but we will observe results and email Dr. C.


I think what this article above by Dr. Costantini does is clarify what many on this forum have been thinking or actually seen in their own case. This is why ""everyone's"" feedback is so important. The feedback helps tremendously in allowing Dr. C to figure out how to properly adjust each person's dose.... even the negative feedback! I think another important thing it does is let people know who started at a random dose, with no guidance from Dr. C, and then got worsened symptoms shortly afterward, that just the fact that their symptoms worsened may mean that they are responsive to HDT. A few people apparently are not responsive to HDT, but apparently even a bad response means you are responsive, but the dose is too high.

I'm glad Dr. C wrote and sent this article, because from my point of view, it represents a major step forward in the evolution and understanding of HDT and I have added a link to it on the " thiamine primer "page !



So a person is to completely stop the B1, all at once? No decreasing the dose little by little over time, just completely stop, wait a week and then try again with a lower dose, half of what the PWPD was taking to begin with?

in reply to cjsg

No, it is not always the same for everyone. If you are just starting and you are in about two weeks or so when you start to notice a worsening of symptoms, then in that situation it may be necessary to stop completely for a week to allow thiamine to be reduced in the system significantly. During this stage of no thiamine supplementation it is important to pay close attention to how your body reacts to the stoppage of HDT and it wouldn't hurt to take notes during this process! At the end of the week or what ever period of time he recommends, you need to let Dr. Costantini know how your body has reacted during the time off from B-1. This information allows him to get a better idea of what the new dose will be and whether the new dose will be up or down from the previous dose.

It is always useful in your notes to mention stressful situations or conditions that might normally exacerbate your PD symptoms. As an example, let's say that somebody very close to you becomes life threatening ill. Well if you just happen to be looking for your ideal dose and this occurs, it could easily influence how you interpret your response to HDT.

Many people fail at around a month or so because they have no guidance from Dr. C. Many people think, how hard can it be, the dose is likely to be somewhere between 300 mg and 5 grams, why do I need Dr. C to help me figure that out? The reason is fairly simple. When you start on HDT, many people are excited because they have read how well so many here on the forum have done on HDT and with that excitement comes expectations of improvements. At one month in, with no guidance from Dr. C. and your symptoms are now worse than when you started HDT, it is easy to become scared because you are now experiencing symptoms that are worse than you have ever known before! Under these conditions it is almost impossible for you to make rational decisions about HDT dosing because you are afraid that what if I don't get better and stay worse like I am right now? This is when having guidance from Dr. C can help you to stay the course and reap whatever benefits HDT has to offer you, but without his guidance, you will only be guided by fear caused by the worsened symptoms and this usually results in people giving up and saying that HDT did nothing for them or it made them worse. It is completely understandable because who wants to be worse today than they have ever been? This is why I consistently suggest contacting Dr. C and staying in touch with him until you find your optimum dose as the best way to test HDT. Not everyone will respond, but the greater majority do and if you are in the majority, you will be able to appreciate the benefits of HDT indefinitely!

If you are two or three months in and possibly close to your ideal dose, then HDT stoppage may only be for three days or so and again, your feedback to Dr. C on how your body reacts to the stoppage of HDT helps Dr. C know which direction to go with dosing and by how much. It seems to me that Dr. C is trying to make smaller adjustments with longer pauses at each dose than just six to nine months ago, but if you notice a major change good or bad after just a day or two of being off of HDT or just after a dosage change then you should let him know what is going on to help him zero in on the proper dose for you.

It is important to remember that if HDT works for you, it will be a life long commitment and as such is worth putting in the proper effort up front!



It seems that no matter how many times we recommend that people contact Dr. C. when they are ready to test HDT, some people choose to go it alone without his guidance for what ever reason they have and this path seems to often have a less than desirable outcome. My thought is that anyone who decides to test HDT, with or without Dr. C's guidance, should take daily notes of changes or effects that they attribute to the HDT or possibly attributable to HDT. These notes can potentially be very useful for DR. C if you are in touch with him, but, if you are not in touch with him, they may be useful down the road if you decide to contact him at a later time as I have seen people try it on their own and then somewhere down the road decide to contact him. If that turns out to be the case for you, those notes will mean that your initial testing without his guidance will not be a complete waste of your time, as the notes will still give him a very good idea of a good starting dose for you as well as insight on how you are responding to HDT!



Since some members are starting to experience the symptoms of mild overdose which manifests as either an increase of old symptoms after being stable for months to over a year or as new symptoms not previously seen before, I thought it was a good time to repost the information from Dr. Costantini regarding overdose and B-1. Just scroll up to the original post to read part of what he had to say on the subject. I am including the following link to a recent post that might also be helpful in explaining in a little more detail why symptoms might worsen after being stable for months to more than a year :



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