| Active Ingredient | Uses based on scientific evidence | Grade* |
| soy (glycine max [l. merr.)] | a phytoestrogen combination may help prevent menstrual migraine attacks. further research is needed before a strong recommendation can be made. | c |
*Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use;
F: Strong scientific evidence against this use.