Benfotiamine is a lipid soluble form of water soluble common Thiamine (B1).
Historically B1 was the only treatment for neuropathy for many years. The typical dose is 100-300mg daily in divided doses.
Then the SSRI antidepressants emerged and also Neurontin (followed by Lyrica) and the treatment for PNs changed and doctors dropped the thiamine. This I believe is a mistake.
Thiamine is easily found in most grocery stores and pharmacies. It remains inexpensive as well. Starting just over a decade ago, this new form called Benfotiamine started appearing in studies.
For quite a while it was not available in US and then when it did start becoming so, it was ferociously expensive. That has now changed.
Here is an informative website on it:
http://www.benfotiamine.org/FAQ.htm
I find it affordable at iherb.com and I use the Doctor's Best brand. The website above endorses much higher doses, than I use and typically recommend. I think for many people 300mg a day is adequate. But we have had some posters here who used 900mg-1200mg daily. At that level, cost will become an issue for many.
I recommend benfotiamine for neuropathies that are not responding to B12 and/or Vit D. Also some people have metabolic problems with the genes that metabolize alcohol. These patients also can benefit from benfotiamine.
I'll also add that beriberi (thiamine deficiency) does occur in some patients and go unrecognized by doctors. This is due to taking some medications that deplete thiamine, like the strong loop diuretics. But it can be due to low dietary intake, high alcohol consumption, or a genetic flaw that then requires higher daily intake. Malabsorption from gluten intolerance/Celiac or inflammatory changes in the GI tract like Crohn's may also cause beriberi. The genetic issue is called vitamin "dependency" and occurs with other vitamins ---B6 for example. People with a vitamin dependency require higher amounts of the vitamin compared to the majority of others.
Here is a link to a medical site on beriberi:
http://emedicine.medscape.com/article/116930-overview
Since the link I gave at the beginning of this post, is very complete, there is not much more for me to say at this point, other than benfotiamine remains a good option to add to any supplement list you may be considering.
edit to add some more links from PubMed on this subject:
http://www.ncbi.nlm.nih.gov/pubmed/20188835
This study does give doses:
http://www.ncbi.nlm.nih.gov/pubmed/18473286
And does reiterate what I post that it takes TIME to show benefits. People often push the dose UP to get faster response IMO.
This is a chemical explanation:
http://www.ncbi.nlm.nih.gov/pubmed/18384109
http://www.ncbi.nlm.nih.gov/pubmed/18220605
Before gabapentin and SSRIs drugs, thiamine was the main treatment for PN. I believe it should remain high in the list for
any PNer and befotiamine is superior IMO. However, benfotiamine at one time was super expensive and few could afford it. That has changed in the last 3 yrs or so.
Thiamine remains inexpensive, but it makes some people have a body odor that limits its use.
This PDF gives some good data:
http://www.altmedrev.com/publications/11/3/238.pdf
This is an older paper:
http://www.ncbi.nlm.nih.gov/pubmed/16359659
This is from 1999:
http://www.ncbi.nlm.nih.gov/pubmed/10219465
I used to use thiamine in bursts. A month or two at a time, in the past. When Benfotiamine became affordable, I changed to it.
I only use 150mg a day now, but I started at 300mg in the beginning. I don't feel it is a cure...but it sure does prevent progression, and take care of alot of the discomfort for me.
I do think some people have a higher genetic requirement for it.
This one from 1996: Germany where the beginning studies originate.
http://www.ncbi.nlm.nih.gov/pubmed/8886748
Edit:
Here is a new link... discussing the better absorption and bioavailability of Benfotiamine vs thiamine:
http://www.ncbi.nlm.nih.gov/pubmed/8929745