Product guidance · Supplements
Benfotiamine for neuropathy: dose, evidence and side effects
Benfotiamine is a form of vitamin B1 that the body absorbs far better than ordinary thiamine, and it is one of the most talked-about supplements for diabetic nerve pain. Here is what the trials found, including the most recent one.
Written by the Managing Neuropathy editorial team under the direction of Dr. Tom Biernacki, DPM, FACFAS · Clinical review pending · Last updated 24 September 2026
The short answer. Benfotiamine is a man-made, better-absorbed form of vitamin B1 (thiamine). Two short trials, of three and six weeks, found signs of a modest improvement in the symptoms of diabetic neuropathy, mainly pain, at doses of 300 to 600 mg a day. The two largest long-term trials, two years in type 1 diabetes and one year in type 2 diabetes (published in 2026), found no measurable benefit to the nerves, and the one-year trial found no significant improvement in symptoms either, although benfotiamine was well tolerated. Some people try it for symptoms with their clinician’s agreement, but the evidence for that is weak. It is not a way to repair nerves, and it doesn’t replace blood sugar control or a proper check for thiamine deficiency.
What benfotiamine is
Thiamine, or vitamin B1, helps the body turn food into energy, and nerves depend on it. Adults need very little, about 1.1 to 1.2 mg a day, but a true deficiency can cause beriberi, which damages nerves, and Wernicke-Korsakoff syndrome, a serious brain disorder. Deficiency is most likely with heavy alcohol use, after weight-loss surgery and in some older adults, and people with type 2 diabetes tend to have lower blood levels of thiamine than people without diabetes.
Benfotiamine is a synthetic relative of thiamine that the gut absorbs much more easily, and the body converts it into thiamine. In one study in healthy volunteers, it delivered about 11 times as much thiamine to the blood plasma as the same dose of ordinary thiamine, and about twice as much of its active form inside red blood cells.
The interest in diabetes comes from laboratory work. In a widely cited 2003 study, benfotiamine switched on an enzyme called transketolase, which diverts the by-products of high blood sugar away from pathways that damage small blood vessels. In diabetic animals, that prevented damage to the retina. Whether the same thing protects human nerves is exactly what the clinical trials set out to test.
What the trials found
| Trial | Who took part | Dose and length | What it found |
|---|---|---|---|
| BEDIP (2005) | 40 hospital patients with diabetic polyneuropathy; a pilot study | 400 mg a day for three weeks | Neuropathy scores improved more than with placebo, pain especially |
| BENDIP (2008) | 165 people with diabetic polyneuropathy | 300 or 600 mg a day for six weeks | The main symptom score improved more than with placebo among people who completed the trial as planned, but narrowly missed statistical significance in the full analysis; results were better at 600 mg, and pain responded best |
| Fraser et al. (2012) | 67 people with type 1 diabetes | 300 mg a day for 24 months | No significant effect on nerve function or inflammation, despite much higher thiamine levels |
| BOND (2026) | 57 people with type 2 diabetes and mild to moderate symptomatic neuropathy | 300 mg twice a day for 12 months | No significant difference in nerve, symptom or quality-of-life measures; one symptom score showed a borderline trend in favor; well tolerated |
The pattern is consistent. The short trials found signs of a modest improvement in symptoms. The long trials, which measured the nerves themselves with nerve conduction tests, skin biopsies and scans of the tiny nerves in the cornea, found no benefit, and BOND, which also tracked symptoms and quality of life for a year, found no significant improvement there either. The NIH Office of Dietary Supplements reaches a similar place: some studies found benfotiamine eased neuropathy symptoms, and larger, longer, better-designed studies are needed.
What that means in practice: benfotiamine may take the edge off symptoms for some people, but there is no good evidence that it slows or reverses the nerve damage itself.
How much to take
There is no official dose for neuropathy. The trials used 300 to 600 mg a day, and the longest ones used 300 mg once or twice a day for one to two years. The trials that found a benefit measured it after three to six weeks, so if you and your clinician decide to try it, about two months at a dose used in the studies is long enough to judge. If nothing has changed by then, the trials give no reason to expect a benefit to appear later.
No upper limit has been set for thiamine, because high intakes haven’t been linked to harm. Benfotiamine has less long-term safety data than thiamine itself, but a year at 600 mg a day in the BOND trial was well tolerated.
Side effects and who should be careful
- Side effects are uncommon and usually mild. In the six-week BENDIP trial, a handful of people had stomach upset or a skin reaction.
- Check combination products for vitamin B6. Many neuropathy formulas pair benfotiamine with B6, and B6 taken over time can itself damage nerves, sometimes at doses well under 100 mg a day, the US upper limit for adults. Australia’s medicines regulator has warned that B6 in supplements can cause nerve damage.
- Pregnancy and breastfeeding. Benfotiamine hasn’t been studied, so avoid it unless your clinician recommends it.
- It is not an emergency treatment. Sudden confusion, unsteadiness or trouble moving the eyes in someone who drinks heavily or has had weight-loss surgery can be Wernicke’s encephalopathy, which needs thiamine given in the hospital right away.
Benfotiamine, thiamine or another supplement?
Plain thiamine is inexpensive and is the standard way to correct a deficiency. Benfotiamine reaches higher blood levels, which is why it is used when the aim is a high dose by mouth.
Alpha-lipoic acid has more trial evidence than benfotiamine for easing the burning and pain of diabetic neuropathy, and it can lower blood sugar, which matters if you take diabetes medicine.
Vitamin B12 helps when you are low in it, which can happen with long-term metformin use. Our guide to supplements for neuropathy ranks the options by the strength of their evidence.
Choosing a product
- Look for an independent quality seal, such as USP Verified or NSF, which checks that the label matches what is inside.
- Check the dose per capsule, so you know how many capsules a day you are taking to reach the amount studied.
- Read the rest of the label for B6 and other added ingredients.
- Skip any product that promises to reverse or cure neuropathy. A supplement can help nerve damage only when a shortage of that nutrient caused it, and even then recovery may be partial; and quick-fix promises don’t hold up.
Common questions
How long does benfotiamine take to work?
The trials that found a benefit measured it after three to six weeks. If there is no change in your symptoms after about two months at a studied dose, it is unlikely to help.
Can benfotiamine repair nerve damage?
There is no good evidence that it can. The two largest long-term trials, two years in type 1 diabetes and one year in type 2 diabetes, found no measurable improvement in nerve function or nerve fibers, even though blood thiamine levels rose sharply.
Is benfotiamine safe to take long term?
It appears to be well tolerated. The BOND trial gave 600 mg a day for a year, and it was well tolerated. Evidence beyond a year or two is limited, so tell your clinician you are taking it.
Is benfotiamine better than alpha-lipoic acid?
For symptoms, alpha-lipoic acid has more trial evidence behind it. The two work differently and some people take both, but there is little research on the combination.
Should everyone with diabetes take benfotiamine?
No. It isn’t part of standard diabetes care, and in the one-year BOND trial, raising thiamine levels with benfotiamine didn’t improve the nerves or the symptoms. If you’re thinking of trying it, ask your clinician first.
Related reading
Supplements for neuropathy · Alpha-lipoic acid for neuropathy · Neuropathic pain · Diabetic neuropathy · Alcohol-related neuropathy · Can you reverse neuropathy in 7 days?
Sources and further reading: NIH Office of Dietary Supplements, thiamin fact sheet for health professionals (requirements, deficiency, groups at risk, benfotiamine studies). Haupt E et al., benfotiamine in diabetic polyneuropathy, a three-week pilot study (BEDIP), Int J Clin Pharmacol Ther 2005;43:71–77. Stracke H et al., benfotiamine in diabetic polyneuropathy (BENDIP), Exp Clin Endocrinol Diabetes 2008;116:600–605. Fraser DA et al., 24 months of oral benfotiamine in type 1 diabetes, Diabetes Care 2012;35:1095–1097. Ziegler D et al., benfotiamine over 12 months in type 2 diabetes with symptomatic polyneuropathy (BOND), BMJ Open Diabetes Res Care 2026;14:e005773. Xie F et al., pharmacokinetics of benfotiamine compared with thiamine hydrochloride, J Clin Pharmacol 2014;54:688–695. Hammes HP et al., benfotiamine blocks three major pathways of hyperglycemic damage, Nat Med 2003;9:294–299. Alzheimer’s Drug Discovery Foundation, benfotiamine research summary (absorption, trial doses, tolerability). NIH Office of Dietary Supplements, vitamin B6 (upper limit and neuropathy from high doses). Therapeutic Goods Administration (Australia), health supplements containing vitamin B6 can cause peripheral neuropathy. Krishnan D, Kiernan MC, neurotoxic risks from over-the-counter vitamin supplements, Med J Aust 2023.
For our Michigan neighbors
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Dr. Tom Biernacki, DPM, FACFAS is a double board-certified foot and ankle surgeon (ABFAS and ABPM) and a Fellow of the American College of Foot & Ankle Surgeons. He is the founder of Balance Foot & Ankle in Howell and Bloomfield Township, Michigan, where peripheral neuropathy, diabetic foot risk and loss of protective sensation are part of his weekly clinic. His patient education videos have drawn more than 950,000 subscribers on YouTube. Managing Neuropathy is written by its editorial team under his direction, to put the explanation he gives in the exam room in front of the people who cannot get to one — including when a product is worth buying and when it is not.