The 5 Best Science-Backed Supplements for Better Sleep

Poor sleep is one of the most common health complaints — and one of the most consequential. Chronic sleep deprivation is linked to weight gain, impaired cognition, elevated cortisol, and a higher risk of metabolic disease.

Before reaching for prescription sleep aids, many people find that targeted supplementation makes a meaningful difference. Here's what the evidence actually supports.

1. Magnesium Glycinate

Why it works: Magnesium activates the parasympathetic nervous system (your "rest and digest" state) and regulates GABA receptors in the brain.

The research: A 2012 randomized controlled trial found that 500 mg of magnesium daily significantly improved sleep time, sleep efficiency, and insomnia severity in elderly adults.

Dose: 200–400 mg magnesium glycinate, taken 30–60 minutes before bed. Glycinate is preferred over oxide — better absorbed, fewer GI issues.

2. Low-Dose Melatonin

Why it works: Melatonin is your body's natural sleep-onset signal. Supplementing can help shift your circadian rhythm and reduce sleep onset latency.

The research: A meta-analysis of 19 studies found melatonin reduced time to fall asleep by ~7 minutes and increased total sleep time by ~8 minutes. Not enormous — but consistent.

Dose: 0.5–1 mg is often enough. The 10 mg doses common in US supplements are almost certainly too high and may cause next-day grogginess.

3. L-Theanine

Why it works: L-theanine, an amino acid from green tea, promotes relaxed alertness by increasing alpha brain waves and GABA activity — without sedation.

The research: A 2019 study found 200 mg of L-theanine before bed improved sleep quality, reduced sleep latency, and decreased sleep disturbances.

Best use: Pairs well with magnesium for an additive calming effect.

4. Ashwagandha (KSM-66)

Why it works: Chronically elevated cortisol is one of the most common drivers of poor sleep. Ashwagandha is an adaptogen shown to significantly reduce cortisol levels.

The research: A 2019 double-blind RCT found 300 mg KSM-66 twice daily improved sleep quality, sleep onset, and morning alertness after 10 weeks.

Best for: People who lie awake with a racing mind or feel "wired but tired."

5. GABA

Why it works: GABA is the brain's primary inhibitory neurotransmitter — it quiets neural activity. Supplemental GABA (specifically PharmaGABA) has been shown to cross the blood-brain barrier.

The research: A small 2009 study found 100 mg PharmaGABA reduced the time to fall asleep by 5 minutes. Evidence is more limited than the others above.

What to Avoid

• Diphenhydramine (Benadryl-based sleep aids): Creates dependency quickly and impairs sleep quality over time
• Very high melatonin doses: Can disrupt your natural production
• Mixing multiple sedating supplements without guidance

CuraVita Rest+

Our Rest+ formula combines magnesium glycinate, L-theanine, low-dose melatonin (0.5 mg), and 5-HTP into a single, calibrated evening formula. No proprietary blends — full doses disclosed on the label.