Benfotiamine is a fat-soluble form of vitamin B1, also called thiamine. Because it dissolves in fat rather than water, more of it enters the bloodstream than the standard form does, and it stays there longer. It only exists as a supplement, and it is most often taken by people managing long-term high blood sugar.
What Is Benfotiamine?
Benfotiamine is a synthetic version of thiamine. Thiamine is one of the B vitamins, and your body needs it to turn food into energy. You get it from pork, whole grains, legumes, and fortified cereals, and most people who eat a reasonably varied diet get enough.
The problem with regular thiamine is that it is water-soluble. Your gut can only absorb so much of it at a time, no matter how much you take. Benfotiamine was developed to get around that. A fat-soluble molecule passes into the bloodstream more easily, so the same dose ends up producing higher blood levels.
Once it is inside the body, benfotiamine converts back into thiamine, and then into thiamine pyrophosphate. That is the active form your cells actually use. So benfotiamine for the body is not doing something thiamine cannot do. It is a delivery problem being solved.
You will not find benfotiamine in food. It only exists as a supplement.
Benfotiamine vs Thiamine
The difference comes down to how each one gets absorbed. Thiamine relies on a transport system in the gut that has a ceiling. Once that system is saturated, taking more does not significantly raise blood levels. Benfotiamine does not depend on it in the same way.
| Thiamine (Vitamin B1) | Benfotiamine | |
|---|---|---|
| Solubility | Water soluble | Fat soluble |
| Absorption | Limited by an active transport system with a ceiling | Less dependent on that system |
| Where you get it | Pork, whole grains, legumes, fortified foods, supplements | Supplements only |
| Active form in the body | Thiamine pyrophosphate | Converts to thiamine, then to thiamine pyrophosphate |
| Typical amounts | Measured in milligrams for daily needs | Measured in hundreds of milligrams in supplements |
One thing worth being clear about. Better absorption does not necessarily mean a better health outcome. Absorption is easier to measure than benefit, and most of what is confidently stated about benfotiamine benefits and side effects online concerns absorption.
The benefits of benfotiamine for diabetes require careful consideration of the research. Some people also compare alpha lipoic acid or benfotiamine to determine which is better for diabetes, and benfotiamine is often discussed alongside the best vitamins and blood sugar supplements for diabetics.
Dr. Ergin explains the difference between thiamine and benfotiamine here.
Why People Take Benfotiamine
Thiamine is required for normal energy metabolism and normal nerve function. That is not a marketing claim; it is what the vitamin does. If someone is running low on thiamine, correcting that shortfall matters.
Benfotiamine raises thiamine levels more effectively than the standard form, which is the whole reason it exists. People taking it are usually doing so because they want more thiamine than a general B complex provides, or because they have been advised to pay attention to their B vitamin status.
Metformin is worth a mention here. It is linked to low B12 in a large share of the people taking it, which is a different B vitamin, but the same general point about long-term medication and vitamin status. We covered that in metformin and B12 deficiency.
You will find a lot of writing online about benfotiamine, nerve health, brain health, and advanced glycation end products. Some of that research is genuinely interesting. Most of it is laboratory or mechanism-level work, which explains how something could work rather than showing that it does work in people over months. We would rather point you at what is settled than repeat what is not.
Benfotiamine Dosage
Most benfotiamine supplements come in 150 mg or 300 mg capsules. Follow the label on the product you buy.
Take it with food. It is fat-soluble, so a meal that contains some fat helps. If you miss a dose, take the next one at the normal time. Do not double up.
Do not increase your dose just because nothing seems to be happening. More of a supplement is not a faster result, and the ceiling on what is sensible is not something to work out by trial and error. If you think you need more, that is a conversation with a doctor.
How Long Does Benfotiamine Take to Work?
Blood thiamine levels rise within hours of a dose. That part is fast. Anything you might actually notice takes considerably longer, and it is worth setting expectations in weeks rather than days.
Three things affect the timeline. The dose you are taking. Whether you were low on thiamine to begin with, because correcting a shortfall is different from adding more on top of adequate levels. And what you are hoping to see change, since some things show up in a blood test and some do not.
If you want to know whether it is doing anything, decide in advance what you are tracking and write it down before you start. A vague sense of feeling better after six weeks is not evidence, and it is very easy to talk yourself into it.
Benfotiamine Side Effects
Most people who take benfotiamine do not report side effects. The ones that come up are usually mild and usually settle. Nausea or an upset stomach is the most common side effect, and taking it with a meal rather than on an empty stomach usually helps. Skin rash comes up occasionally, and that's a reason to stop and speak to a doctor rather than push through.
One specific point. The benfotiamine molecule contains sulfur. If you have a known sensitivity to sulfur-containing compounds, raise it with your doctor or pharmacist before you start rather than after.
Stop taking it and get medical help if you develop swelling, difficulty breathing, a spreading rash, or if you feel suddenly and severely unwell. In the United States, you can also report a suspected supplement reaction to the FDA through MedWatch.
Who Should Avoid Benfotiamine
Talk to a doctor before taking it if any of these apply to you.
- You take insulin, a sulfonylurea, metformin, or a GLP-1 medication. If you take insulin or a sulfonylurea, read up on low blood sugar first.
- You are pregnant or breastfeeding.
- You have liver or kidney disease. Kidney function matters more than most people realize when it comes to what your body clears, and we go into it in diabetes and kidney disease.
- You have surgery coming up.
- You already take several supplements marketed for blood sugar because it is easy to stack similar ingredients without realizing it.
- You have had a reaction to a supplement before.
- You have a known sulfur sensitivity.
There is not a long list of documented benfotiamine drug interactions, and that is worth reading correctly. A short list can mean a compound has been studied and found to interact with little, or it can mean nobody has looked very hard. For a supplement, it is usually closer to the second. The absence of a documented interaction is not evidence of safety.
If you are on any diabetes medication, the practical move is to take the bottle to your pharmacist along with your full medication list. That takes five minutes, and it is the single most useful thing on this page. Our guide to metformin interactions you must know covers what to watch for if metformin is one of them.
How to Choose a Benfotiamine Supplement
The supplement aisle does not make this easy, so here is what actually matters.
- A complete Supplement Facts panel. You should be able to see the exact amount of benfotiamine per serving, not a proprietary blend that hides it.
- A dose you can work with. 300 mg per capsule is the most common strength, and it is easier to adjust than an unusual number.
- A lot number and an expiry date on the bottle.
- Third-party testing for identity, potency, and contaminants. This is different from a manufacturing certification, and it is different again from being made in an FDA-registered facility. None of those three mean the FDA has approved anything, because the FDA does not approve supplements before they go on sale.
- A company that will send you a certificate of analysis if you ask for one.
SugarMD Benfotiamine 300mg provides 300 mg per capsule. It is formulated by Dr. Ahmet Ergin, an endocrinologist, and, like everything else on this page, it is a dietary supplement rather than a treatment for any condition.
Frequently Asked Questions
What Is Benfotiamine Used For?
Benfotiamine is taken as a supplement to raise thiamine levels in the body. Thiamine is needed for normal energy metabolism and normal nerve function.
Is Benfotiamine the Same as Vitamin B1?
Not quite. Benfotiamine is a fat-soluble version of vitamin B1 that your body converts back into thiamine after absorbing it. The end result is the same vitamin, but more of it gets in.
How Much Benfotiamine Should I Take?
Supplements usually contain 150 mg or 300 mg per capsule. Follow the label on the product you buy, and ask a doctor what makes sense for you rather than adjusting it yourself.
How Long Does Benfotiamine Take to Work?
Blood thiamine levels rise within hours. Anything you would notice takes longer, so think in weeks rather than days. Decide what you are tracking before you start.
Does Benfotiamine Have Side Effects?
Most people do not report any. Nausea, stomach upset, and skin rash come up occasionally. Take it with food if it unsettles your stomach, and stop and see a doctor if you get a rash.
Can I Take Benfotiamine With Metformin or Insulin?
Ask your doctor or pharmacist first, and take the bottle with you along with a list of everything else you take. Do not change the dose of any prescribed medication because you have started a supplement.
Is Benfotiamine Better Than a B Complex?
They do different jobs. A B complex gives you a small amount of several B vitamins, which suits general topping up. Benfotiamine gives you a much higher dose of one of them in a form that is more easily absorbed. Neither is better in the abstract.
Is Benfotiamine FDA-approved?
No. Benfotiamine is sold as a dietary supplement, and the FDA does not approve supplements for safety or effectiveness before they reach the market. Phrases like "made in an FDA-registered facility" describe the facility, not an approval of the product.
Medically Reviewed
Written by the SugarMD editorial team. Medically reviewed by Dr. Ahmet Ergin, endocrinologist.
This article is for general information and is not medical advice. Benfotiamine is a dietary supplement. It is not intended to diagnose, treat, cure, or prevent any disease. Speak to your own doctor before starting any supplement, particularly if you take medication for blood sugar.