Best Supplements for Deep Sleep (Not Just Falling Asleep)

Mike HartnettEvidence-Based

7+ years researching longevity protocols. Runs a 20+ supplement daily stack. Built CoreStacks after losing his father to heart disease.

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Most over-the-counter sleep aids help you fall asleep but do little for deep sleep — the restorative stage where your body repairs tissue, consolidates memory, and releases growth hormone. According to Dr. Andrew Huberman, the supplements with the strongest evidence for improving deep sleep specifically are magnesium threonate, glycine, and apigenin, which work through different mechanisms than sedative-type sleep aids.

Why Deep Sleep Matters More Than Total Sleep

Deep sleep (slow-wave sleep) makes up roughly 15–25% of total sleep time in healthy adults, but its importance is disproportionate. According to Dr. Matthew Walker, author of Why We Sleep, deep sleep is when the brain’s glymphatic system clears metabolic waste, including amyloid-beta proteins linked to Alzheimer’s disease.

Dr. Peter Attia has discussed on The Drive that deep sleep declines significantly with age — by your 50s, you may get 50–60% less deep sleep than in your 20s. This decline correlates with accelerated aging markers, making deep sleep optimization a key longevity strategy.

For a detailed breakdown of sleep optimization protocols, see our Huberman Sleep Protocol guide.

Supplements That Target Deep Sleep

Magnesium Threonate (Magtein)

Magnesium threonate crosses the blood-brain barrier more effectively than other magnesium forms. A 2010 study in Neuron found it increased brain magnesium levels and improved synaptic plasticity. Huberman takes 145mg of magnesium threonate nightly, specifically for its effects on sleep depth.

We compared dozens of sleep supplements by ingredient quality and third-party testing. See our top sleep supplements for 2026.

Glycine

A 2015 study in Neuropsychopharmacology found that 3g of glycine before bed lowered core body temperature and improved subjective sleep quality. The temperature drop is key — your core temperature needs to fall 1–3 degrees for deep sleep initiation. Dr. Huberman has cited this research on his podcast.

Apigenin

This flavonoid, found in chamomile, acts on GABA receptors to promote relaxation without heavy sedation. Huberman includes 50mg of apigenin in his nightly sleep stack. Research is still emerging, but preliminary data suggests it may support slow-wave sleep specifically. For a closer look at how apigenin stacks up against other natural sleep aids, read our apigenin for sleep guide.

Ashwagandha (KSM-66)

A 2020 study in the Journal of Ethnopharmacology found that ashwagandha root extract improved sleep quality scores and reduced sleep onset latency. Dr. Brad Stanfield has noted that the KSM-66 extract has the strongest clinical evidence among ashwagandha forms.

Supplements That Help You Fall Asleep (but Not Stay Asleep)

For context, these common sleep supplements primarily affect sleep onset, not deep sleep architecture:

For our full roundup of sleep supplements, check out the best supplements for sleep in 2026.

The Huberman Deep Sleep Stack

Dr. Huberman’s nightly protocol for deep sleep optimization, as discussed across multiple podcast episodes, includes:

Magnesium glycinate is the foundation of most sleep stacks. See our best magnesium glycinate supplements for the highest-quality options.

• 145mg magnesium threonate — 30–60 min before bed
• 50mg apigenin — 30–60 min before bed
• 100–400mg L-theanine (optional) — for those with racing thoughts

He emphasizes that behavioral interventions (cool room temperature, dark environment, consistent schedule) should come before supplements. The supplements are enhancers, not replacements for good sleep hygiene.

Magnesium Forms Compared: Which One Actually Helps Sleep?

Not all magnesium is the same. There are a dozen commercially available forms, and only a few have meaningful evidence for sleep:

Magnesium threonate is the only form with published data specifically on brain magnesium levels and cognitive function. Dr. Huberman favors it for deep sleep because of its ability to cross the blood-brain barrier, as discussed on multiple Huberman Lab episodes.

Magnesium glycinate combines magnesium with glycine, giving you two sleep-supporting compounds in one supplement. The glycine component lowers core body temperature (as covered above), and the magnesium itself supports GABA activity. Dr. Brad Stanfield includes magnesium glycinate in his recommended protocol and considers it the best general-purpose form for sleep and recovery.

Magnesium citrate has decent bioavailability but primarily affects the gut. It is better known for its laxative effect than for any sleep benefit. If deep sleep is your goal, skip it.

Magnesium oxide is cheap and everywhere, but it has roughly 4% absorption. Not useful for sleep.

For a full head-to-head breakdown, see our magnesium supplementation guide, which covers dosing, timing, and which form fits your specific goals. And if you are specifically weighing magnesium against melatonin for sleep, we compared them directly in our magnesium glycinate vs melatonin comparison.

Timing and Stacking: How to Take Deep Sleep Supplements

Timing matters more than most people realize. You cannot take a handful of supplements at dinner and expect them to kick in at midnight.

30–60 minutes before bed is the sweet spot for magnesium threonate and apigenin. Huberman has been consistent about this window across multiple Huberman Lab episodes.

Glycine is more flexible. The 2015 study used glycine taken right at bedtime. Some people dissolve 3g in warm water as a pre-bed drink — it tastes slightly sweet, making it one of the easier supplements to take in powder form.

Do not stack everything on night one. Start with one supplement for a week, assess your sleep quality (ideally with a tracker like Oura or WHOOP), then add the next. If you throw in magnesium, glycine, apigenin, and ashwagandha simultaneously, you have no idea what is actually working.

Dr. Peter Attia has made this point on The Drive: treat your supplement protocol like an experiment. One variable at a time. Track the outcome. Adjust. For a broader look at how the top longevity experts structure their full stacks, see our expert stacks comparison.

Frequently Asked Questions

How do I know if I’m getting enough deep sleep?

Wearable sleep trackers like WHOOP, Oura Ring, and Apple Watch estimate deep sleep stages. According to Dr. Peter Attia, most adults should aim for 60–90 minutes of deep sleep per night. If you consistently get less than 45 minutes, optimizing sleep environment and considering supplements may help.

Can I take all these deep sleep supplements together?

Magnesium threonate, glycine, and apigenin can generally be combined safely, as Dr. Huberman has discussed. However, always start with one supplement at a time to gauge individual effects, and consult your healthcare provider if you take prescription medications.

Why does melatonin not help deep sleep?

According to sleep researchers, melatonin primarily signals to your brain that it is time to sleep — it regulates circadian timing rather than sleep architecture. Some studies suggest high-dose melatonin (5–10mg) may actually suppress REM and deep sleep stages, which is why experts like Huberman recommend low doses (0.5–1mg) if used at all.

Disclaimer: This content is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider before starting any supplement regimen.