Clinical sources

The research behind our ingredients

Explore the human clinical trials and findings related to Ashwagandha, L-Theanine, Magnesium Glycinate and GABA.

The studies below used a range of doses, which may differ from the amounts in NuVida Sleep. They show what research has found about each ingredient, not results for our specific formula.

Ingredient

Ashwagandha

Randomized, double-blind, placebo-controlled

Stress and anxiety reduction

In this study, 64 adults with chronic stress were randomly assigned to receive either Ashwagandha root extract or a placebo for 60 days. The Ashwagandha group showed a significant reduction in stress and anxiety scores measured by standardized questionnaires. Additionally, there was a notable decrease in serum cortisol levels. The researchers concluded that Ashwagandha extract is effective in improving resistance to stress and enhancing overall well-being.

Chandrasekhar, K., Kapoor, J., & Anishetty, S. (2012). A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of Ashwagandha root in reducing stress and anxiety in adults. Indian Journal of Psychological Medicine, 34(3), 255-262.

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Randomized controlled trial

Improvement in muscle strength

This randomized controlled trial involved 57 male participants engaged in resistance training. Participants received either Ashwagandha extract or a placebo for eight weeks. The Ashwagandha group exhibited significantly greater increases in muscle strength and size, as well as a reduction in exercise-induced muscle damage. The study suggests that Ashwagandha supplementation can enhance muscle mass and strength during resistance training.

Wankhede, S., Langade, D., Joshi, K., et al. (2015). Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trial. Journal of the International Society of Sports Nutrition, 12, 43.

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Ingredient

L-Theanine

Randomized, double-blind, placebo-controlled

Sleep quality and stress in healthy adults

In this crossover study, 30 healthy adults (average age 48) took 200 mg of L-theanine per day for four weeks and a placebo for four weeks, in random order. Compared to placebo, L-theanine reduced time to fall asleep, sleep disturbances and the use of sleep medication, as measured by the Pittsburgh Sleep Quality Index. Participants also reported lower stress, anxiety and depression scores. The researchers concluded that L-theanine may help promote mental health in adults with stress-related complaints.

Hidese, S., Ogawa, S., Ota, M., Ishida, I., Yasukawa, Z., Ozeki, M., & Kunugi, H. (2019). Effects of L-theanine administration on stress-related symptoms and cognitive functions in healthy adults: a randomized controlled trial. Nutrients, 11(10), 2362.

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Ingredient

Magnesium Glycinate

Randomized, double-blind, placebo-controlled

Insomnia severity in adults with poor sleep

In this study, 155 healthy adults aged 18 to 65 who reported poor sleep were randomly assigned to take magnesium bisglycinate (250 mg of elemental magnesium per day, the same glycine-bound form as magnesium glycinate) or a placebo for four weeks. The magnesium group saw a greater reduction in Insomnia Severity Index scores than the placebo group (3.9 points versus 2.3 points), with most of the improvement appearing in the first two weeks. The researchers described the benefit as modest.

Schuster, J., Cycelskij, I., Lopresti, A., & Hahn, A. (2025). Magnesium bisglycinate supplementation in healthy adults reporting poor sleep: a randomized, placebo-controlled trial. Nature and Science of Sleep, 17, 2027-2040.

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Randomized, double-blind, placebo-controlled

Primary insomnia in older adults

In this study, 46 older adults with insomnia received 500 mg of magnesium or a placebo daily for eight weeks. Compared with placebo, the magnesium group showed improvements in insomnia severity scores, sleep efficiency, sleep time, time to fall asleep and early morning awakening.

Abbasi, B., Kimiagar, M., Sadeghniiat, K., Shirazi, M. M., Hedayati, M., & Rashidkhani, B. (2012). The effect of magnesium supplementation on primary insomnia in elderly: a double-blind placebo-controlled clinical trial. Journal of Research in Medical Sciences, 17(12), 1161-1169.

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Magnesium amounts varied between studies.

Ingredient

GABA

Randomized, double-blind

Sleep onset and efficiency in adults with insomnia

In this study, 40 adults with insomnia symptoms took 300 mg of GABA (from fermented rice germ) or a placebo daily for four weeks. Sleep was measured in a sleep lab with polysomnography. In the GABA group, the time it took to fall asleep dropped from about 13 minutes to under 6 minutes, and sleep efficiency rose from 79% to 86%. Self-reported sleep quality and insomnia scores also improved, and no serious side effects were reported.

Byun et al. (2018). Safety and efficacy of gamma-aminobutyric acid from fermented rice germ in patients with insomnia symptoms: a randomized, double-blind trial. Journal of Clinical Neurology, 14(3), 291-295.

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Randomized, double-blind, placebo-controlled

Low-dose GABA and deep sleep

A follow-up study gave 54 adults with insomnia a lower dose of 75 mg GABA or a placebo daily for four weeks, again measured with polysomnography. In the GABA group, time to fall asleep dropped from 9.0 to 4.8 minutes, deep (N3) sleep increased and nighttime arousals decreased. No adverse events were reported.

Yoon et al. (2022). Efficacy and safety of low-dose gamma-aminobutyric acid from unpolished rice germ as a health functional food for promoting sleep: a randomized, double-blind, placebo-controlled trial. Journal of Clinical Neurology, 18(4), 478-480.

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Disclaimer: Always consult a healthcare professional before starting any new supplement regimen. The information provided is for educational purposes and was last reviewed in September 2026.

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