Melatonin and stomach cramps

January 24, 2024 7:52 AM

If melatonin use has caused stomach cramps is there a chance that will go away or if you have them once, will you likely get them again?

I started using 1mg melatonin liquid for sleep issues. I ate a small snack just before it as I'd read taking it with food helps. The next evening I got sudden but shortlived stomach cramp which I didn't connect to it, so I took it again. Next morning I got nasty stomach cramp (no vomiting or diarrhoea just intense pain) which lasted an hour and then I saw that this was a known side effect

Does this mean I have to give up any idea of using melatonin? Or is it a shortlived thing or is there a different way I could take it that might avoid this?

posted by Flitcraft to Health & Fitness (7 answers total)

A couple of things. Unless you got the melatonin from a reputable source and it has the "USP" logo, there is no guarantee that it contains any particular dose of melatonin. Could be nothing at all, could be 5x what the label says. Could contain serotonin, which is a controlled substance. Truly amazing that a so-called dietary supplement can be sold like a medicine and be a total crapshoot, but here we are.

The second is that even the 1 mg dose of melatonin is quite high, relative to natural melatonin levels. Studies of doses as low as .1 mg seem to work the same as higher doses. (To be clear, I'm not aware of any evidence that higher doses are unsafe.) So if you're having a reaction you might try cutting the pill in halves or fourths.
posted by wnissen at 9:33 AM on January 24, 2024 [2 favorites]

Advice from my Dr: if a medication gives you stomach cramps,
try taking it immediately after a full meal - the meal will slow the absorption and buffer your stomach, so you are less likely to get cramps.
posted by chariot pulled by cassowaries at 10:10 AM on January 24, 2024 [1 favorite]

Best answer: In RCTs of melatonin for insomnia, GI distress is a very rarely reported adverse effect, affecting on the order of 1 in 500 patients. Experiencing this symptom 12-24 hours after taking the supplement further reduces the likelihood this was due to melatonin, whose half-life for elimination is less than an hour. Another potential explanation is that you are responding to one of the inactive ingredients in the liquid melatonin preparation you're taking, so you could try switching to a different brand or formulation (like a tablet).
posted by telegraph at 10:43 AM on January 24, 2024 [1 favorite]

Response by poster: Thanks so it might be worth another go but I'll cut the quantity just in case and try eating more beforehand
posted by Flitcraft at 1:21 PM on January 24, 2024

It could also be something in the liquid that's not melatonin that's giving you a problem. Changing brands may solve your issue.
posted by AlexiaSky at 6:06 PM on January 24, 2024 [1 favorite]

I have 1 mg gummies and I cut them into pieces the size of a small grain of rice before giving them to my kids.
posted by bq at 6:27 PM on January 24, 2024 [1 favorite]

Response by poster: Update - cutting the dose works and maybe it was something else causing the stomach pain issue after all. Thanks!
posted by Flitcraft at 4:56 AM on January 25, 2024