Vitamin B1 (Thiamine)
Also known as Thiamine, Thiamin, Thiamine mononitrate
Thiamine is essential for converting carbohydrates into usable energy, and it supports nerve signalling and cardiovascular function. Deficiency is rare in developed countries but can occur with heavy alcohol use, bariatric surgery, or a diet high in refined carbohydrates.
Benefits
Supports energy metabolism
StrongThiamine pyrophosphate is a required cofactor for several enzymes that turn glucose into ATP.
Maintains nerve health
StrongRequired for healthy nerve conduction; deficiency causes peripheral neuropathy and confusion.
May help blood sugar control
PreliminarySome studies suggest thiamine supplementation improves endothelial function and glucose handling in people with diabetes.
Pros & cons
Pros
- Critical for cellular energy production
- Very safe and inexpensive
- Needed for alcohol-related deficiency recovery
Cons
- Dietary deficiency is uncommon in well-fed populations
- Not a stimulant, it restores normal function, not extra energy
Side effects
Very rare allergic reactions
Thiamine is water-soluble and generally considered safe at standard doses.
How to take it
Typical dose
1–1.5 mg per day (RDA); 100–300 mg for therapeutic use
Timing
With meals to improve absorption
Tip: Thiamine HCl and mononitrate are standard water-soluble forms. Benfotiamine and TTFD are lipid-soluble and may reach higher tissue levels for nerve and vascular health.
Forms: which one to choose
The main forms of Vitamin B1 (Thiamine) compared by absorption, tolerability, and best use.
Thiamine HCl
Most popularHigh absorptionBest for: General deficiency prevention and energy support · Standard water-soluble B1 form; very inexpensive
Read about Thiamine HClThiamine Mononitrate
High absorptionBest for: General deficiency prevention and energy support · More stable than HCl in dry supplements; slightly less water-soluble
Read about Thiamine MononitrateBenfotiamine
High absorptionBest for: Nerve health, advanced glycation end-product concerns · Fat-soluble form with higher tissue penetration
Read about BenfotiamineThiamine Tetrahydrofurfuryl Disulfide (TTFD)
High absorptionBest for: People who do not respond to standard thiamine; nerve and brain health · Lipid-soluble disulfide form that crosses the blood-brain barrier well
Read about Thiamine Tetrahydrofurfuryl Disulfide (TTFD)What the research says
Thiamine deficiency and neuropathy
StrongThiamine deficiency is a well-documented cause of peripheral neuropathy and Wernicke encephalopathy.
How it connects
Relationships between Vitamin B1 (Thiamine) and other supplements in the matrix.
Magnesium is required for thiamine-dependent enzymes to function properly.
Compare the pairingBoth support calm alertness, but high thiamine doses are rarely needed alongside a balanced B-complex.
Compare the pairingFrequently asked questions
What is Vitamin B1 (Thiamine) used for?
Vitamin B1 (Thiamine) is most commonly used for energy, brain health, and heart health. Thiamine pyrophosphate is a required cofactor for several enzymes that turn glucose into ATP.
How much Vitamin B1 (Thiamine) should I take?
A typical dose is 1–1.5 mg per day (RDA); 100–300 mg for therapeutic use. Thiamine HCl and mononitrate are standard water-soluble forms. Benfotiamine and TTFD are lipid-soluble and may reach higher tissue levels for nerve and vascular health. Start at the lower end and confirm the right dose for you with a healthcare professional.
When is the best time to take Vitamin B1 (Thiamine)?
Recommended timing: With meals to improve absorption.
What are the side effects of Vitamin B1 (Thiamine)?
Reported side effects include very rare allergic reactions. Thiamine is water-soluble and generally considered safe at standard doses.
More Vitamins
Folate (B9)
The active B vitamin behind methylation, mood, and pregnancy health.
Vitamin B12 (Cobalamin)
The methylation and nerve-health vitamin that protects the brain and blood.
Vitamin B2 (Riboflavin)
The flavin cofactor behind energy, antioxidant defence, and migraine prevention.
Compare Vitamin B1 (Thiamine) with
Weighing your options? See how Vitamin B1 (Thiamine) stacks up against similar supplements.