Primal Sleep should work a little, in that it has 3mg of melatonin (although this is realistically the very bottom end of the effective range for adults), and the 100mg of GABA should do something, although once again, this is near the bottom end of effective . Beyond that the ingredients are either laughably underdosed, like hops extract, at 40x below the effective range or lavender extract which simply doesn't work at all when taken orally. Then there's magnesium glycinate which is only 14% magnesium meaning you only get 14mg,  when you need 200 or more for it to be effective for sleep quality. This is pretty much a common theme with Primal sleep, with L Tryptophan and Lemon Balm struggling with the same issue.
As a result the ingredients in Primal Sleep can have a mild impact on getting to sleep quicker, but aren't really going to do much for sleep quality. And if we look at a slightly more expensive competitor (RestAgaain at $10 a bottle more) you get 10mg of melatonin, 300mg of GABA, 20x the magnesium, as well as double the valerian root. It swaps the ineffective hops, lemon balm, lavender extract and chamomile extracts, for the well backed calcium, ashwagandha, 5htp, L theanine, and vitamins d, b6 and b12. All within the effective dosage range. In short, primal sleep may be ever so slightly cheaper than what we rate as the number one sleep aid supplement available over the counter, but it's nowhere near as good value or as effective.
Primal Harvest Sleep simply isn't a great supplement and ultimately a cheaper melatonin supplement would do the same job for half the price, but if you're looking for a more premium and comprehensive supplement then go with RestAgain .
Customers reviews of primal sleep generally agree with our sentiment, in that it gets only 3* on Amazon even after the obviously paid reviews, the general sentiment is that it puts you to sleep a little quicker, but doesn't do much else.
There weren't many complaints about primal sleep side effects, although some people did mention having particularly vivid dreams which is consistent with known melatonin side effects.
Although Primal Harvest Sleep reviews generally didn't complain about this being too bad. Oddly some people did specify that it made them wake up needing the bathroom, but this seems to be simply one or two cases.
In terms of positive rather than negative primal sleep reviews (filtering the fake ones) all we really saw was people talking about falling asleep faster as the only one of the claimed benefits of primal sleep that holds up.
We gave primal sleep to two of our testers, and it faired pretty much as we'd have expected based on the ingredients list. Both testers reported that it did not work as well as their usual sleep aids, and when taken as described on the bottle resulted in little to no effect whatsoever the tester who was used to a higher dose of melatonin. As for our second tester, they simply stated that it did not work, and noted slightly more vivid dreams.
For the most part Primal Sleep is safe. As mentioned in the customer review sections there are some known primal sleep side effects which come from melatonin or valerian, most commonly vivid dreams or mild nausea. It is possible for higher doses of melatonin to cause daytime grogginess, but this is unlikely due to the low dose in primal sleep. However, please consult your physician if you're taking any other medications especially if it's related to blood pressure as there are known interactions with melatonin.
Valerian Root 150mg - Even at a 4:1 extract which is pretty standard we'd be looking for a slightly higher amount of valerian root for it to be in it's most effective range of 600mg as these sorts of extracts simply aren't as bioavailable so the 4:1 comes out more like 400mg. Although this should still have an impact for better sleep quality.  it's not a bad sleep aid, but the dose in the primal sleep supplement isn't quite as high as we'd like even if it's one of the better ingredients in here. There are enough studies that back it's use in general, and these say it works best after being taken consistently for a week or so. It does also have evidence to suggest it helps with mental health and anxiety reduction. And it is within the effective range for this as a concentrated extract. Good ingredient, but done better in other supplements.
L-Tryptophan 100mg - L Tryptophan is a precursor for serotonin, and it is a good ingredient for a sleep aid in that it's been shown to reduce insomnia in multiple clinical trials, the catch is that the dosing was 1-4grams, 10-40 times the amount in primal sleep supplements meaning once again we have an under dosed and thus ineffective ingredient.  Generally speaking 5htp is a better alternative for combined sleep supplements as it is similarly effective, but requires a much lower dose, 150mg meaning it requires less capsule space. The catch is that it's more expensive, meaning that Primal Sleep have likely taken the cheaper option here.
GABA 100mg - This one is OK, it is at the bottom end of the effective dosage for sleep, which is something we seem to be saying a lot in our primal sleep review, but it should still work. GABA is the precursor to our body's natural production of the important sleep hormone melatonin. It's one of the ingredients that we expect to see in any good sleep aid, it will help you fall asleep more quickly and stay asleep. Generally, it works best when taken for at least a week 30 mins to an hour before bed. 
Chamomile Extracts 100mg - Chamomile tea has been shown to help people fall asleep in numerous trails, however, this was only in people who did not suffer from insomnia, and it was found to have no effect on people who do suffer with sleep issues. There is less evidence to back that it works at all when taken in pill form. That said the small amount of research that there has been on Chamomile promoting restful sleep had it dosed at 10x the amount in Primal Sleep. 
Lemon Balm Extract 100mg - Lemon balm extract simply doesn't work at this low dose either, we're starting to feel like a broken record, the only study to show that lemon balm did do anything for insomnia, was only in patients who's insomnia was rooted in anxiety and the dose was 500mg or 1000mg, not the 100mg that we have in primal sleep. Once again, nice idea, ineffective execution. 
Hops Extract 50mg - As we already mentioned in the intro, this is nowhere near enough hops extract to have any benefits from the dietary supplement, in larger doses it has been shown to promote natural sleep and is particularly effective at helping people stay asleep. Although as we've stated you need 20 - 40 times as much as the dose in Primal Sleep. 
Lavender extract 50mg - Lavender extract dose absolutely nothing when consumed orally, the evidence to support lavender working as a sleep aid is solely down to it's scent. Which as you'd expect isn't particularly applicable if you're consuming it in pill form. All studies that tested it orally have shown it had no benefit against a placebo. 
Melatonin 3mg - This is the bottom end of the effective range for melatonin, although it is the most potent over the counter sleep aid, which is where the only positive comes from in most primal sleep reviews, it will help you get to sleep faster. It even typically works within about 30 mins to an hour as melatonin is the hormone that tells your body it's time to go to sleep. It's a good inclusion, but it's at the bottom end of dosing, if you're a hyper responder, or it's your first time with any sort of sleep aid supplement then it should be reasonably effective, but it's more for helping you get to sleep than maintaining a deep sleep even if it does benefit that a little. 
Magnesium Bisglysinate Chalate 100mg - The fact is that magnesium bisglysinate is a good ingredient, but you need at least 200mg of magnesium for it to be effective and the total content in this compound is 14mg. It's highly bioavailable, which is good if you're taking it as a standalone supplement, but the dose in primal sleep will do nothing to help you get a good night's sleep. 
The same problems both ourselves and customers Primal Sleep reviews have with the supplement is simple, you don't get anything extra for your money than you'd get from any normal melatonin supplement at half the price.
And the simple reason for that is all of it's additional ingredients are under dosed to the point where there's pretty much no way in which they could promote restful sleep, as a result we can't recommend primal sleep and instead would recommend that you either try a much cheaper straightforward melatonin supplement or spend the extra $10 and get RestAgain which is simply a much better sleep aid.
1 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7527439/
2 - https://pubchem.ncbi.nlm.nih.gov/compound/Magnesium-glycinate
3 - https://ods.od.nih.gov/factsheets/Valerian-HealthProfessional/
4 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908021/
5 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2995283/
6 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4245564/
7 - https://pubmed.ncbi.nlm.nih.gov/22849837/
8 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4505755/
9 - https://www.nccih.nih.gov/health/melatonin-what-you-need-to-know
10 - https://pubmed.ncbi.nlm.nih.gov/23853635/