1. Magnesium glycinate, the sensible first choice
Magnesium earns the top spot on an unglamorous basis. A large share of adults fall short of the recommended intake, correcting a genuine shortfall is associated with better sleep quality and fewer night cramps, and the downside risk is close to zero at sensible doses. It's also the cheapest thing in this list.
Form matters more than brand here. Magnesium oxide, the cheapest and most common option on shelves, absorbs poorly and mostly acts as a laxative. Glycinate absorbs well, is gentle on the gut, and carries glycine, which has its own calming reputation.
Take 200 to 400mg of elemental magnesium in the evening with food. Loose stool is the signal you've gone too high. Our magnesium glycinate guide covers the citrate comparison and the kidney caveat in full, and the NIH magnesium fact sheet has the intake data behind the shortfall.
2. Ashwagandha, if stress is the actual problem
Ashwagandha has more randomized trial data than almost any other herbal supplement, and the most consistent finding is reduced self-reported stress alongside measurable drops in cortisol over about eight weeks.
Sleep improvements show up reliably in one specific group: people whose sleep problems track their stress. If you lie awake with a racing mind, this is a reasonable thing to try. If your sleep is broken for other reasons, expect less.
Use a standardised extract at 300 to 600mg a day, because KSM-66 and Sensoril are what the trials actually used. And read the cautions properly. It can raise thyroid hormone levels, it's contraindicated in pregnancy, and rare liver injury reports exist. Our ashwagandha guide lays those out alongside the cortisol trial the claims rest on.
3. Melatonin, useful for the right problem at the wrong dose
Melatonin is widely misunderstood. Rather than sedating you, it acts as a timing signal that tells your body night has arrived. That makes it genuinely effective for jet lag and shifted sleep schedules, and much weaker for ordinary insomnia.
The dosing situation is worse than the evidence. Products commonly sell 5mg and 10mg, while the trials supporting a phase shift used 0.5mg to 3mg taken a few hours before target bedtime. More is not better here, and higher doses are associated with next-day grogginess. The NIH melatonin overview is a good sanity check before buying.
If you're crossing time zones, it's a good tool. If you simply can't fall asleep at home, it's probably the wrong one.
4. DSIP, the one we'd skip
Delta sleep-inducing peptide has an unbeatable name and very little behind it. The published human work is old, small and inconsistent, and there's no trial establishing a dose or a safety profile for the way it's actually used.
It's also a research chemical, not a supplement. It has no approved consumer form, and the vendors selling it, including BioLongevity Labs, sell it under research-use-only terms that buyers attest to at checkout. Amino Club also lists it, at $29.99 with an open price and public COA, cheaper than BioLongevity's listing but no better evidenced.
We list DSIP on our research peptide rankings page because people search for it and the vendor documents it consistently, right down to the $55.97 listing and its public COA. That's a statement about paperwork, not about sleep. Between DSIP and a $15 bottle of magnesium glycinate, the magnesium wins by a wide margin.
Two other research peptides get pulled into the same conversation, usually on weaker grounds. Epithalon is marketed around pineal gland function and circadian rhythm, but the human data behind that claim is thin. CJC-1295 & Ipamorelin gets discussed alongside sleep because growth hormone release peaks during deep sleep, which is a real physiological fact stretched into a marketing claim the trials don't actually support. Both belong in the same category as DSIP: interesting mechanism, not a sleep aid with evidence behind it.
A different legal category: hemp-derived sleep gummies
Outside supplements and research peptides entirely, hemp-derived CBN and THC sleep gummies are a fast-growing category with their own, separate evidence base for sleep, built mostly around CBN and low-dose THC rather than any of the four ingredients above.
Erth Wellness sells a CBN + THC + live resin terpene sleep gummy at 750mg and a separate THC-free CBN sleep gummy for people who want to avoid THC specifically. These are a materially different legal and regulatory category from magnesium or ashwagandha, hemp-derived cannabinoids under the 2018 Farm Bill framework, not dietary supplements, and state law on them varies. Worth knowing about if you've tried the four options above without success and want to understand the full landscape before deciding what's right for you.
What actually beats all four
This part is unfashionable and it's still true. Sleep timing, light exposure and caffeine cutoff move sleep quality more than any capsule in this list.
A consistent wake time, morning daylight, a dark cool room, and no caffeine after early afternoon. None of it is monetisable, which is roughly why it gets less airtime than supplements do.
Treat supplements as the thing you add after those are in place, not instead of them. And if you're dealing with genuine insomnia rather than poor sleep habits, that's a conversation for a doctor. Cognitive behavioural therapy for insomnia outperforms every supplement on this page.
