The human body naturally produces Melatonin as part of the processes leading to sleep. An area of the brain called the superchiasmatic nucleus detects falling light levels, leading to an increase of Melatonin in the brain, and sleepiness. This can be thrown off through the use of artificial lights, by shift work, jet lag, staying up later on weekends, etc. For those who are having regular difficulty falling asleep, lowering the lights an hour before bedtime may help to raise Melatonin enough to overcome that problem. At other times, it might be helpful to take a Melatonin supplement like this one. As always, it is important to communicate with your physician. It is also possible to check for interactions using apps like epocrates. I have never come across interactions with Melatonin. Researchers keep working, though, so what is true today could be a little different tomorrow. Currently, Melatonin is being investigated as potentially helpful across a wide variety of disorders, may of which are associated with age. Those who are interested might wish to look that up. A very conservative starting place is the NIH National Center for Complementary and Integrative Disorders. That website will not jump ahead on anything too quickly, so if you are interested in the very latest developments then keep going through the scientific literature. What to expect with Melatonin: This dose of 3 mg is convenient as it is going to work quite well for most people These are solid tablets. If you have never taken Melatonin before, then you could use a pill splitter to try out a 1.5 mg dose or so, and see how that goes. Most people will go on to the 3 mg dose. However, there are some people who may find that they do not seem to clear the Melatonin easily, and then using this may leave them sleepy in the morning. That is not the usual response; those who have morning drowsiness are few and far between. If it happens to you, and you have allowed for a good long sleep ("normal" is 8 or 9 hours per night), then do cut back or stop use and figure out why it is affecting you in that way, because that should not be the case. If you tried to get away with a short sleep, well, you are part of the human race so for your own better health it's best to figure out how you can get those 8 or 9 hours. Many people who have told me that they have too much to do so that is impossible, find that they function so much better that once they are getting enough sleep regularly, they are still able to get everything done. If you are allowing those 8 - 9 hours to sleep and still find that Melatonin leaves you groggy in the morning, then it may take the help of medical professionals to figure out if there is some interaction, genetic anomaly, or... ? Using Melatonin is by far much safer than taking pharmaceutical sleep medicines. There is no comparison! For example, the genetic zolpidem that is sold under Am_bien and other names has been found to substantially raise the risk of multiple cancers (risks begin to increase after only 3 doses), it only adds about 20 minutes of sleep, and it interferes with memory so what actually happens is that patients do not remember the sleeplessness, and think that it works better than it does. The memory problems often extend to other things, too. An internet search of the generic name already given here will take you to that research; add the word "Cancer" if you want to know more about that unfortunate effect from pharmaceutical sleep medication. It should be included in the inserts that patients receive; sadly, it is not! Melatonin is not a pharmaceutical; it is what your body produces in order to sleep, so it is great that we can have it on hand to boost the levels when that is needed. Finally, down to the particulars of this brand. I've tried it, and find that it is a good quality product. It arrives with a clear seal over the cap that comes off with no difficulty (just twist the cap and it will go). Do watch for that safety seal, though. So far, mine have also arrived with an inner removable flat seal and some cotton. It does take Melatonin a while to work. It will vary depending on whether your stomach is empty, etc., and with use you'll learn how much leeway to allow. I find that I should take it about 45 - 60 minutes before I would like to sleep. Then it will provide me with a "sleep window" of about an hour during which I can fall asleep. If I get busy and work past it, then I can miss that window. I tend to get busy, so it is helpful to me to set a timer or a reminder on my phone to go to bed. I've had this on subscription for a while; that has allowed for extra savings. I am needing to take this less and less often, though, so when I realized that I can change my subscription I thought that I might provide this information in case it will be helpful to someone else. Take care, and sweet dreams