Most of the Insomnitol customer reviews are pretty positive, as you'd probably expect. On Amazon it has a 4.2 rating which is very respectable and as far as we can tell there's very few fake reviews in amonst them.
The negative insomnitol reviews simply say that the product didn't work for them or gave them nightmares which are potential side effects of some of it's ingredients so we didn't see anything unexpected there either.
All in all these are good customer reviews for a decent product.
1 - https://www.nccih.nih.gov/health/valerian
2 - https://www.nccih.nih.gov/health/passionflower
3 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4245564/
4 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2995283/
5 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7527439/
6 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6836118/
7 - https://www.nccih.nih.gov/health/melatonin-what-you-need-to-know
8 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7796270/
9 - https://pubmed.ncbi.nlm.nih.gov/29665762/