Homo C.,Bcomplex is completely different from B1, so this implication concerning thiamine and insomnia is inapplicable.
Astolfo, thiamine will slow your breathing/heart rate, for which reason it is perfect for getting ready for bed. I take 300mg with my last meal before bed (zero-fat dairy, fruit, gelatin, honey) with some magnesium.
Are you referring to Thiamine hcl?