You don;t actually need a B-complex. What you need is Biotin which is part of a B-complex. Biotin is a water soluable vitamin as well and B5 depletes biotin (just like ALA does), but since your mega dosing it depletes it to a larger extent. For this reason I would get a biotin 300mg, or 1000mg and take one in the morning and one at night. To be honest I don't think there is enough biotin in a b-complex to account for the great amount of B5 that you will take when megadosing so I would definitely just buy biotin instead. A biotin difficency causes very dry lips, as well as it can cause you to lose hair or for your hair to thin out.