The customer reviews are mostly positive, but then as melatonin works for most people this isn’t a surprise. The overall rating Alteril on Amazon was 4.2* which is pretty reasonable. There were a few people who said it simply didn’t work.
The other negative Alteril reviews talked about even one pill being too strong (which is something we’ll talk about later, but 5mg of melatonin may be for some people. This resulted in grogginess and lethargy the next day.
This is all in all pretty much what we’d expect to see, which lends credibility to the overall review score not being faked.
We’re going to give Alteril it’s fairest shake which is looking at the 2 capsule dose rather than the 1, this is largely because L Tryptophan is most effective in the 200mg and up range (which otherwise it wouldn’t be).
Melatonin is most effective at either 3mg, 5mg or a 10mg dose, 10mg would often be too much and result in daytime drowsiness for people just starting out with the supplement. 5 can be for some people although this is unusual. It is however another reason we generally recommend RestAgain as this can be broken down into 3mg dosages.
This should be taken under advisement, it isn’t necessarily a negative as you have the option to dose according to your own needs. Whereas 10mg in a single pill would be too much.
10mg Melatonin – Melatonin is the hormone your body produces to tell you to go to sleep, as such supplementing it tends to work pretty quickly. This is a good inclusion as we mentioned in the intro and it’s well backed  there are no complaints with containing melatonin, there is the small risk of side effects such as particularly vivid dreams or nightmares in some cases and as we mentioned earlier, although in general it proves to be a very good alternative to harder solutions, so it’s a good ingredient for Alteril, we’d just recommend taking only one pill to start. Melatonin has also been shown to help people stay asleep longer and have a deeper less disturbed sleep, although it’s main function is getting to sleep.
200mg L Tryptophan – The main issue here is that the studies are mixed, there’s a reasonable amount of backing and 200mg would be the correct dose , although if we compare it to GABA which has the same function of releasing serotonin (GABA is also the precursor to melatonin) then we don’t rate it’s inclusion particularly highly. There is also the issue that L Tryptophan isn’t tolerated as well as GABA and has a higher likelihood of leading to nausea.  There is some evidence to support deeper sleep, but this is very limited.
60mg Proprietary Blend Of Valerian Root and Chamomile Extract - Whilst Valerian is a good ingredient, the dosage here is simply too low to do anything at all. As for Chamomile extract, this is a common ingredient, but not a good one. There are some studies that show chamomile tea itself can work as a sleep aid, that is when it is consumed as a tea  this doesn’t seem to be the case when taken as a pill although one or two studies have shown some positives they are far outweighed by the negative studies. And the dosage would have to be at least 5 times higher to have any effect.
Alteril should be safe for most people, the main catch is if someone is particularly sensitive to Melatonin, in which case we’d say steer clear.
There are several potential side effects of alteril, most notably nausea or grogginess the next day which are as a result of L Tryptophan and Melatonin respectively.
We would generally recommend taking one to start with, although ideally you should have already tried a weaker melatonin supplement before to make sure you’ll avoid any side effects.
1 - https://www.nccih.nih.gov/health/valerian
2 - https://ods.od.nih.gov/factsheets/Valerian-HealthProfessional/
3 - https://www.nccih.nih.gov/health/melatonin-what-you-need-to-know
4 - https://www.ncbi.nlm.nih.gov/books/NBK534823/
5 - https://pubmed.ncbi.nlm.nih.gov/23077193/
6 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8181612
7 - https://pubmed.ncbi.nlm.nih.gov/31006899/