We do see that you left a review on the 1 oz amber bottle with droppers, which is different from the 1 dram you purchased however, because evaporation is somewhat common with this type of lid we would suggest make sure to dilute any oil that is going to be in a dropper so less oil is 'lost' and only add a dropper when you know you will be using that oil frequently, or for thicker oils that do not tend to make drops as easily.