There is discrepancy in the structure of ar-turmerone reported in some scientific publications and in the 12th Edition of the Merck Index. The Merck Index structure lacks the methoxy group (H3CO-) reported in scientific publications. Thus, there is misleading information about at least one compound present in turmeric, perhaps the very one responsible for its benefits at the 50 mg/day dosage. Medically-oriented organizations recommend 8 grams of curcumin from turmeric a day, but this is much larger than the amount of unaltered herb found to be beneficial, so curcumin probably is not the most biologically active ingredient in turmeric The more potent ar-turmerone may positively influence indole metabolism at both the kynurenine, and serotonin and melatonin levels.