Vitamin B1

Vitamin ·Strong evidence ·Reviewed May 2026

Essential for energy metabolism, nerve function, and carbohydrate metabolism. First B vitamin discovered.

Evidence tier

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What it's good for

Energy production¹⁷
Nerve function^2,7
Carbohydrate metabolism¹⁷
Brain health¹⁴

What to watch for

Generally well tolerated
Rare allergic reaction
None significant

The bottom line

Evidence rating strong. Most-documented uses: energy production, nerve function, carbohydrate metabolism. 19 sources indexed (2005–2025), with 7 interaction records on file.

The science

How it works, mechanistically.

Core mechanism

As thiamine pyrophosphate (TPP), serves as a coenzyme for pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase in the Krebs cycle, and transketolase in the pentose phosphate pathway.^17,1

Class

B Vitamin

Found in food

Pork, Whole grains, Legumes

Low-status signs

Fatigue, Nerve damage (beriberi)

Absorption

Water-soluble; take with food

Dosing

Dosing & protocol.

Common range

50–100 mg daily

Recommended form

Benfotiamine (fat-soluble, better bioavailability) or thiamine HCl

Water-soluble; take with food to reduce GI upset^16,1

Dosing protocol

Maintain · 50-100 mg/day with breakfast

Water soluble; safe at supplemental doses. Benfotiamine (fat soluble) is preferred for diabetic neuropathy.^11,16

No cycling requiredNo tolerance buildup

Forms

Forms & what to buy.

Ranked by evidence and value.

Benfotiamine Recommended

Rank 1: lipid-soluble thiamine derivative with higher exposure. Head-to-head bioavailability or pharmacokinetic evidence supports this ranking (PMID: 24399744). Not a direct replacement for all thiamine-dependent contexts.

Premium150-300 mg/day

Thiamine HCl

Rank 2: water-soluble standard form. Inexpensive and reliable for deficiency prevention.

Budget50-100 mg/day

Thiamine Mononitrate

Rank 3: stable tablet form. Similar practical role to thiamine HCl.

Budget50-100 mg/day

TTFD

Rank 4: lipid-soluble disulfide derivative. Can be stimulating or sulfur-sensitive for some users.

Premium50-100 mg/day

Cost

What it actually costs.

Real-world pricing across three quality tiers. Assumes Benfotiamine / Thiamine HCl.

BudgetBest value

$1.20 /mo

$0.04 per dose

Mid

$3.00 /mo

$0.10 per dose

Premium

$6.60 /mo

$0.22 per dose

Assumes 50-100 mg/day. Vendor basis: NOW/iHerb, Vitacost, Life Extension, and Amazon marketplace; benfotiamine is the premium form. Updated 2026-05-28.

From food

The same dose, as food.

How much you'd eat to match a supplemental dose.

1.2 mg thiamine

About 3 ounces pork plus sunflower seeds or beans

Whole grains and legumes help, but enrichment also contributes.

50 mg thiamine

Far more than normal food intake

Higher-dose thiamine protocols are supplemental, not dietary.

Lab work

Markers to track.

What to test, the optimal window inside the conventional range, and how long a response takes.

Whole Blood Thiamine B1

Effective thiamine repletion should raise whole-blood thiamine into range.^1,2

Optimal

100–180 nmol/L

Conventional

70–180 nmol/L

Responds in

2-6 weeks.

70optimal180

Consider this more strongly in people using loop diuretics, alcohol heavily, or with high-output states.

LactatePyruvate

Why people use it

Symptoms it's matched to.

Where this appears in the symptom-to-supplement map, ranked by relevance.

Alcohol cravings / reduction support

78% relevance

Thiamine (B1) is often depleted by alcohol use and is critical for nerve and brain function, making repletion important during reduction.^1,3

MoodModerate evidenceThiamine HCl or benfotiamine tablet, 100 mg daily

Thiamine repletion is medically standard in heavy drinkers to prevent neurological harm; coordinate with a clinician.

Hangover and alcohol recovery (liver support)

74% relevance

Alcohol depletes thiamine and impairs its absorption, and repletion is important to protect against neurological complications.

DigestiveStrong evidenceThiamine (benfotiamine for better absorption)

Thiamine repletion is a genuine clinical priority in heavy or chronic drinkers, not just for hangovers.

Low appetite / poor appetite

68% relevance

Thiamine deficiency is a classic cause of anorexia and poor appetite, and correcting it restores normal intake.^10,15

DigestiveModerate evidenceCapsule, 50 to 100 mg daily

Most relevant when intake is poor, with heavy alcohol use, or after bariatric surgery; benefit depends on an underlying deficiency rather than general supplementation.

Peripheral neuropathy / nerve discomfort

66% relevance

Thiamine is essential for nerve energy metabolism, and its fat-soluble form benfotiamine may reach nerves better to ease neuropathic symptoms.^2,7

NeurologicEmerging evidenceBenfotiamine

Benfotiamine is absorbed better than standard thiamine; particularly relevant in diabetic neuropathy.

Fatigue / low energy

59% relevance

Thiamine is foundational for carbohydrate metabolism and nerve function, especially in depleted states.^17,1

EnergyModerate evidenceThiamine

More relevant when diet quality is poor or diuretics are in play.

Sciatica / nerve-root pain

58% relevance

Vitamin B1 (thiamine) is essential for nerve energy metabolism and is commonly combined with B12 and B6 in nerve support formulas, though sciatica specific evidence is limited.^12,1

NeurologicEmerging evidenceBenfotiamine (fat soluble thiamine), 100 to 300 mg daily

Often used as part of a B-complex for nerve health; benfotiamine absorbs better than standard thiamine.

Protocols

Featured in protocols.

Evidence-based stacks that include it, with the exact dose and timing each one uses.

Peripheral Nerve and Neuropathy Support Protocol

NeurologicalOptionalEmerging evidenceAdvanced$35-65/mo

Dose here

100 mg

Timing

Morning with food

Thiamine status matters for glucose metabolism and nerve function, and diabetes can increase thiamine turnover. Evidence for neuropathy support is emerging and often based on thiamine derivatives, so this is deficiency-oriented support.^17,1

Hangover and Alcohol Recovery Protocol

RecoveryCoreModerate evidenceBeginner$15-35/mo

Dose here

50-100 mg

Timing

Before sleep after drinking or the next morning

Alcohol intake can worsen thiamine status, and thiamine repletion is medically important in heavy or chronic alcohol exposure. For occasional hangover recovery it is supportive nutrition, not a cure.^1,3

Genetics

Who responds differently.

SLC19A2pathogenic thiamine transporter variants~0.1% of population

Defective high-affinity thiamine transport has been shown in thiamine-responsive megaloblastic anemia syndrome fibroblasts (PMID 10074490).

Recommendation: Known thiamine transporter disorders require clinician-directed thiamine therapy, not routine wellness dosing.

Safety

Full safety detail.

Side effects

Generally well tolerated
Rare allergic reaction

Contraindications

None significant

Interactions