Supplement analysis backed by scientific evidence · PT

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Limited evidenceVitamins & minerals

TTFD (Allithiamine)

A fat-soluble thiamine derivative that raises blood thiamine much more than plain thiamine. What it does clinically is almost unstudied: one 10-child uncontrolled pilot and a negative exercise trial are the bulk of the human data.

Evidence last reviewed: August 2026

What the science says

  • Raises thiamine levels better than plain thiamine Moderate evidence

    A crossover bioavailability study in 7 volunteers compared 100 mg doses of benfotiamine, fursultiamine (TTFD) and thiamine disulfide; the lipid-soluble derivatives produced far higher plasma and red-cell thiamine than water-soluble thiamine, with benfotiamine highest.

  • No effect on exercise performance Limited evidence

    A randomized double-blind crossover in 14 cyclists given 1 g/day TTFD for 4 days found no difference from placebo in VO2peak, lactate threshold, submaximal oxygen uptake or 2000 m time-trial performance.

  • Autism pilot is not evidence Limited evidence

    An uncontrolled pilot in 10 autistic children reported clinical improvement in 8 after two months of TTFD suppositories. With no control group and ten participants, this cannot support any claim; it is the study most often cited for TTFD.

Dosage & safety

Studied doseSupplements usually supply 50–100 mg/day. Study doses ranged from 100 mg (bioavailability work) to 1 g/day (the exercise trial). No dose has been validated against a clinical outcome.
SafetyA sulfurous body odour and nausea are commonly reported by users. There is no long-term safety data at supplement doses and none in pregnancy. Genuine thiamine deficiency with neurological or cardiac signs is a medical emergency treated with parenteral thiamine, not with a supplement.

Scientific references

Where to buy

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