While I like that only one drop is needed to it is extremely difficult to get that one drop out. Very frustrating, won't buy again for that reason.
My husband and I have used these D3 drops from Carlson for some time. We find they work well and our blood tests for Vitamin D confirm that. We have to do two things though to get the best use out of this product: One is shake the bottle well before each use, to make sure the carrier oil and D3 are well-mixed and we get some D3 with each drop. Step two is then to simply hold the bottle totally upright, not tilted and not shaken any more, and the drop comes out very quickly. The directions tell you to do that since it is a glass bottle (a glass container is much better for the liquid oil-based ingredients) and not a plastic squeeze bottle, but we weren't following the directions at first so did not know how easy the drops are to use. When the bottle gets close to empty, we simply store it upside down in the box between uses to make sure we can get the last drops out easily. We still shake it a little before each use though, to mix the carrier and D3.