I looked at RCTs on clinicaltrials.gov and melatonin supplementation appears to result in slight, but to me significant, sleep improvements. Latency decreases by about 15-20 minutes and the percentage of time asleep increases by 5-10%. That's about 45 minutes a night. Doses used vary but are clustered around 1-4 mg.
I suffer from frequent insomnia and, on nights when I take melatonin I "seem" to sleep a little bit more (unfortunately I sometimes forget - I plan on correcting that). Very anecdotal and N of 1.
It is odd that government RCTs show a slight improvement in sleep yet the message I get from the media and doctors is that melatonin doesn't really do much of anything outside of jet lag.
But it has a small study size and no baseline so hard to draw conclusions.
I also found one null study.
All in all, I wouldn't bet much on it, but melatonin "might" improve sleep quality. Sleep quality and quantity are important for general health and for the cancer fight.
I found this:"Multiple databases were searched yielding 35 randomized controlled trials (RCTs) meeting the review’s inclusion criteria, which were assessed for methodological quality as well as for melatonin effectiveness. The majority of included studies were high quality (83.0%). Overall, according to Grading Recommendations, Assessment Development and Evaluation (GRADE) methodology, weak recommendations were made for preventing phase shifts from jet lag, for improving insomnia in both healthy volunteers and individuals with a history of insomnia, and for initiating sleep and/or improving sleep efficacy."
Response to melatonin seems to vary by individual. A few family members have tried it and said they could not tell if it had any effect, but its effects on me (at several different doses, from 1 mg to 20 mg) have not felt great: very intense and vivid dreams, which I rather enjoy, but followed by waking in the middle of the night with trouble getting back to sleep, then followed by a groggy and un-refreshed beginning to my day.
I really WANT it to work for me because of the other potential benefits I read about, but have yet to find a timing and dosing that works well.
For insomnia I prefer a small dose of trazodone (50 mg), which makes me drowsy within half an hour of ingestion. I still dream more vividly than normal but seem less likely to waken at undesired times and less likely to have morning grogginess. [Discovered this a few years back when our arthritic old dog was prescribed some and I also had some pain keeping me up at night (no, not my wife) and borrowed some of the dog's meds.]
Most nights I can't fall asleep withOUT melatonin (edited because the original draft had it backwards), even though I'm on a handful of medications that tend to result in sleepiness. I have a bottle of 3mg tablets at my bedside with a bottle of water. I sometimes will take a second dose if I wake up and have trouble falling back to sleep before 3am. It's slightly recreational because I'm much more likely to have dreams when I take it.
It also has potential anti-cancer effects, and I believe one member here is taking 40mg a night for that reason. IMHO, it's one of the safer substances to experiment with and find out the dosing and timing that work best for you.
On an unrelated note, I also sleep better if I stop playing a mobile racing game a bit before bedtime. Getting a little adrenaline going in the evening doesn't seem to promote sleep, but can help me stay up until a more reasonable bedtime.
I take between 20-30mg a night and it seems to help me (also take the higher dose for other possible therapeutic benefits). This dose allowed me to reduce my dosage of mirtazapine (Remeron) down to around 5mg, which is pretty low and still get decent nights sleep. These higher doses helped me reset the body clock, but everyone is different. One important thing though is to watch how much you eat in the evening as it can effect glucose tolerance. Should avoid eating late at night in anycase, but if your dosing up on melatonin is is even more important.
Your N =1 is the only 1 that matters here. Assess for your individual self if your sleep improvement is meaningful and at what dose, frequency and timing. Vivid dreams can be a bonus or a nuisance.
Speaking of vivid dreams brought back my vivid dream memory. About ten years ago I used blue blockers. For the first 3 nights, my dreams were amazingly vivid and I slept like a baby. I can still remember one of the dreams (I was on the crew of a pirate ship - not a fun thing).
Unfortunately, after 3 nights both effects went away completely. After that I read that what happened to me is exactly what happens to some other people when they block blue light.
Might be worth a shot again. Blue light supposedly interferes with melatonin production.
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