I have found that most drugs for which I feel an effect don't last as long as the label says. Generally the effect lasts about 4-5 hours where the expectation is 8 hours. I've done time-released medications and supplements, some work fine (or at least well enough), others not so much.
Out of an abundance of caution, me and my medical team tend to take more pills of smaller doses more often. I spread them out through the day or in the case of 'as needed' medications, I am able to take them 'as needed' more often.
Alcohol, also being a drug for which I feel an affect, works much the same as other drugs. I feel the effect quicker, it fades quicker, and on the extremely rare occasions when I achieve a hang over it starts and ends much quicker, such that by early morning it's run it's course.
Hope this helps.
Good luck,
Tek