Though studied since the 1950s, good evidence of ALA efficacy in peripheral neuropathy remains equivocal. The best results seem to be with intravenous forms. ALA has very low bioavailability. This can be enhanced to some extent by using the R isomer and taking it with lecithin on an otherwise empty stomach. There is some evidence that it has synergy with B12 and benfotiamine (again most likely considerably more bioavailable via IV route).