The Lactaid helps me; don't know what you mean by "overdo" it; you take one before a meal you are going to have dairy in, it's an enzyme so doesn't do anything "magic" like an antacid or something might, it just does it's very particular job if it needs doing. I also take one at night before bed; I sometimes have a piece of chocolate candy or have meds I take that have lactose in them (milk chocolate isn't just a fun name :-) But most yogurts are fine without as they are very low lactose and the live cultures take care of what's left. At night, what I thought was indigestion/acid was actually the recent lactose so, while a Tum often helped, the Lactaid in there with my other vitamins/pills, etc. often did too, when the Tum wasn't as effective. Now I take the Tum too though, for the Calcium; it seems to help me sleep better and with less arthritis pain.