NutriDex

The Supplement Research Compendium
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Sulbutiamine

Lipophilic vitamin B1 derivative marketed for fatigue and focus.

Mixed evidence 🧠Nootropic

✚ Updated · How we grade evidence

Evidence tier
Mixed
Research weight
Citations
8 verified / 8
Classification
Nootropic
❝
What the evidence says. Graded mixed: it is a real fatigue drug in some countries, but the largest RCT (n=326) found no lasting benefit at 28 days, and most positive data are small, open-label, adjuvant, or industry-linked. Promising signals exist but the controlled evidence is thin and inconsistent. (Mixed evidence: Conflicting results across studies; benefit uncertain.)

What is Sulbutiamine?

Sulbutiamine is a nootropic used for marketed for asthenia (fatigue). NutriDex grades the human evidence as Mixed. Sulbutiamine is a synthetic, fat-soluble derivative of vitamin B1 (two thiamine molecules linked by a disulfide bond) that crosses the blood-brain barrier more readily than thiamine. It is sold in some countries as an anti-asthenic (anti-fatigue) drug and online as a nootropic. The evidence is genuinely mixed. The largest controlled trial, in 326 people with post-infectious fatigue, found a transient day-7 improvement in women on 600 mg but no significant benefit by day 28. Small studies suggest it may help memory as an add-on to donepezil in early Alzheimer's, ease the behavioural slowing of depression alongside an antidepressant, and reduce fatigue in multiple sclerosis (open-label, n=26). Most trials are small, short, uncontrolled, or industry-linked, and reviewers stress that better randomized trials are needed. It is not a proven stand-alone treatment for healthy people seeking energy or focus.

Purported Benefits

✓Marketed for asthenia (fatigue)
✓Claimed energy & alertness
✓Adjuvant in depression-related slowing
✓Possible memory adjuvant (unproven)

Evidence by outcome

The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.

OutcomeEvidenceEffectStudies
Reduce asthenia/fatigueLargest RCT (n=326) showed only a transient day-7 benefit in women, gone by day 28; observational data more positive but uncontrolled. Mixed ↔ mixed · small 2
Ease psycho-behavioural slowing in depression (adjuvant)8-wk RCT add-on to clomipramine reduced behavioural inhibition but had no antidepressant effect itself. Preliminary ↑ benefit · small 1
Memory adjuvant in Alzheimer'sOne randomized trial added to an anticholinesterase improved memory; small, not replicated. Preliminary ↑ benefit 1
Energy/alertness in healthy peopleNo controlled human evidence supports stand-alone use for energy or focus in healthy users. No Evidence — no effect

Dosing & Compounds

Typical Dose
Typically 400-600 mg/day orally (often as 200 mg tablets), usually limited to a few weeks; no long-term dose is established.
Active Compounds
Sulbutiamine (di-thiamine ester)Thiamine (vitamin B1) precursor

Safety & Cautions

Generally well tolerated short-term; reported effects include nausea, headache, insomnia, mild agitation, tremor and skin rash, and in people with bipolar disorder it has worsened mood symptoms. A case report describes escalating, compulsive use, so it is not recommended for people with bipolar disorder, psychosis, or a history of substance misuse. Long-term safety is unstudied, and it has not been tested in pregnancy or breastfeeding. Because it is a thiamine derivative active in the brain, use caution combining it with other stimulants, antidepressants, or psychiatric medications, and tell your clinician if you take it. Educational only — always check with your doctor or pharmacist before combining Sulbutiamine with any medicine.

Key Studies

RCT Sevim 2017 ✓ PubMed
Open-label, 26 MS patients on 400 mg/day for 2 months: mean Fatigue Impact Scale fell from 77 to 60.5 (p<0.01), no control group.
RCT Tiev 1999 ✓ PubMed
RCT in 326 post-infectious fatigue patients: 600 mg gave a day-7 benefit in women but no significant effect on fatigue by day 28.
RCT Loew 2000 ✓ PubMed
8-week RCT vs placebo + clomipramine: sulbutiamine 600 mg/day reduced psycho-behavioural inhibition in major depression but had no antidepressant effect itself.
RCT Ollat 2007 ✓ PubMed
Randomized double-blind trial: adding sulbutiamine to an anticholinesterase improved episodic memory and daily activities in early/moderate Alzheimer's.
Safety Douzenis 2006 ✓ PubMed
Case report: a patient with bipolar disorder escalated sulbutiamine use, missed psychiatric care, and worsened outcomes — flagging misuse potential.
Review Bizot 2005 ✓ PubMed
Animal study: chronic sulbutiamine improved object-recognition memory and reduced dizocilpine-induced amnesia in rats (mechanistic, not human).
Review Trovero 2000 ✓ PubMed
Rat study: sulbutiamine modulated cortical glutamatergic and dopaminergic transmission, a proposed basis for its claimed nootropic action.
Cohort Shah 2003 ✓ PubMed
Prospective observational study, 1772 patients: sulbutiamine added to anti-infective treatment fully resolved asthenic symptoms in 51.7%; side effects 0.6%.
8 sources cited · 8 verified Search all studies on PubMed ↗

Common questions about Sulbutiamine

What is Sulbutiamine used for?

Sulbutiamine is most often taken for Marketed for asthenia (fatigue), Claimed energy & alertness, Adjuvant in depression-related slowing, Possible memory adjuvant (unproven). Lipophilic vitamin B1 derivative marketed for fatigue and focus.

Does Sulbutiamine work — what does the evidence say?

Mixed evidence. Conflicting results across studies; benefit uncertain. Sulbutiamine is a synthetic, fat-soluble derivative of vitamin B1 (two thiamine molecules linked by a disulfide bond) that crosses the blood-brain barrier more readily than thiamine. It is sold in some countries as an anti-asthenic (anti-fatigue) drug and online as a nootropic. The evidence is genuinely mixed. The largest controlled trial, in 326 people with post-infectious fatigue, found a transient day-7 improvement in women on 600 mg but no significant benefit by day 28. Small studies suggest it may help memory as an add-on to donepezil in early Alzheimer's, ease the behavioural slowing of depression alongside an antidepressant, and reduce fatigue in multiple sclerosis (open-label, n=26). Most trials are small, short, uncontrolled, or industry-linked, and reviewers stress that better randomized trials are needed. It is not a proven stand-alone treatment for healthy people seeking energy or focus.

What is the typical dose of Sulbutiamine?

Typically 400-600 mg/day orally (often as 200 mg tablets), usually limited to a few weeks; no long-term dose is established.

Is Sulbutiamine safe? Any cautions or side effects?

Generally well tolerated short-term; reported effects include nausea, headache, insomnia, mild agitation, tremor and skin rash, and in people with bipolar disorder it has worsened mood symptoms. A case report describes escalating, compulsive use, so it is not recommended for people with bipolar disorder, psychosis, or a history of substance misuse. Long-term safety is unstudied, and it has not been tested in pregnancy or breastfeeding. Because it is a thiamine derivative active in the brain, use caution combining it with other stimulants, antidepressants, or psychiatric medications, and tell your clinician if you take it.

How many studies support Sulbutiamine?

NutriDex cites 8 sources for Sulbutiamine, graded "Mixed".

Cite this page
APA

Peh, D. (2026). Sulbutiamine: Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 26 Jun 2026, from https://nutridex.info/s/sulbutiamine

BibTeX
@misc{nutridex_sulbutiamine,
  author       = {Peh, Daryl},
  title        = {Sulbutiamine: Benefits, Dosage, Side Effects \& Evidence},
  year         = {2026},
  howpublished = {NutriDex --- The Supplement Research Compendium},
  url          = {https://nutridex.info/s/sulbutiamine},
  note         = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-06-26}
}

For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.

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