How long a vial lasts depends very much on the person using DERQX. So you can't give an exact answer to this. We sometimes say: it lasts just as long as a bottle of good Cognac. You can enjoy it for a very long time, but you can also empty it in a few evenings.

Do you use it every day or just for special occasions? In any case, it is very economical to use. You don't need a drop at a time.

A bottle of DERQX contains 3ml, which is about 100 small drops. Enough for 100 special occasions.