← All supplements
Limited evidenceBrain & cognition

Sulbutiamine

A lipophilic thiamine derivative that crosses into the brain more readily than thiamine. Marketed for fatigue and focus on the strength of a handful of small, mostly uncontrolled studies.

Where to buy

View on iHerb

Ships to 180+ countries · welcome discount for new customers

Referral link — this site may earn a commission on purchases.

What the science says

  • Fatigue Limited evidence

    An open study in patients with multiple sclerosis reported reduced fatigue scores with sulbutiamine, and older trials in post-traumatic asthenia described similar improvements. None was placebo-controlled with an adequate sample, and no trial has tested it for everyday tiredness in healthy adults.

  • Cognition in Alzheimer's disease as an add-on Limited evidence

    A multicentre randomized trial combining sulbutiamine with an acetylcholinesterase inhibitor in early to moderate Alzheimer's disease reported an effect on episodic memory and attention subscores but not on the primary global measure. The finding has not been replicated.

  • Nootropic use in healthy people Limited evidence

    A review of sulbutiamine notes that its pro-cognitive reputation rests largely on rodent object-recognition work and on small clinical series in asthenia; there is no controlled trial of memory or focus in healthy adults.

Dosage & safety

Studied doseClinical use has been 400–600 mg/day, usually in two divided doses taken in the morning. Cycles of a few weeks are typical because tolerance is commonly reported anecdotally.
SafetyReported effects include headache, nausea, insomnia and, less often, agitation or mood elevation; case reports describe misuse and dependence at high doses. It is a prescription drug in some countries and is not approved as a supplement everywhere. Avoid in bipolar disorder, and in pregnancy and breastfeeding, where data are absent. It does not substitute for treating an underlying cause of fatigue.

How to take it

TimingMorning and early afternoon in two divided doses - a late dose commonly causes insomnia.
With food?With food; it is a fat-soluble thiamine derivative, so a meal containing fat helps absorption.
Worth knowingUsers consistently report tolerance within a few weeks, which is why clinical use is in short courses - if you find yourself raising the dose to get the original effect, that is the signal to stop, not to escalate.

Frequently asked questions

Does sulbutiamine work for fatigue?

The evidence is limited: small, mostly uncontrolled studies in multiple sclerosis and post-traumatic fatigue reported improvement, but no adequate placebo-controlled trial exists and it has never been tested for everyday tiredness in healthy adults.

Does sulbutiamine improve focus or memory?

There is no controlled trial of sulbutiamine for memory or focus in healthy adults; its nootropic reputation rests on rodent work and small clinical series, so the evidence is limited.

How much sulbutiamine should I take?

Clinical use of sulbutiamine has been 400-600 mg/day in two divided doses in the morning and early afternoon, in short cycles of a few weeks. A late dose commonly causes insomnia.

Can you get addicted to sulbutiamine?

Case reports describe misuse and dependence at high doses, and tolerance within a few weeks is commonly reported. If you find yourself raising the sulbutiamine dose to get the original effect, stop rather than escalate, and avoid it with bipolar disorder.

Scientific references

Related in Brain & cognition