Best Sleep Supplements for Testosterone and Recovery: What the Evidence Shows

Sleep and testosterone are closely linked. Testosterone rises after you fall asleep^[1], and in a controlled study of 10 young men, one week of 5-hour nights lowered daytime testosterone by 10 to 15 percent.^[2] So it is natural to wonder whether anything that improves sleep could help. But the supplement market is full of bold claims, and the evidence varies a lot from one ingredient to the next.

This guide looks at the most common sleep supplements through one lens: what do human trials actually show for sleep, and what do they show for testosterone? In most cases, the honest answer is that the evidence is early or limited, so we have not ranked them with scores.

Magnesium

Magnesium is a mineral involved in many enzyme reactions in the body.

Sleep. A systematic review of three randomized trials (151 older adults with insomnia) found magnesium shortened sleep onset by about 17 minutes compared with placebo. All three trials were at moderate-to-high risk of bias, and the authors rated the evidence low to very low quality.^[3] There is little trial evidence in younger men.

Testosterone. In a small study, 4 weeks of magnesium supplementation (10 mg per kg body weight, which is 700 mg for a 70 kg man and exceeds the 350 mg supplemental upper limit discussed below) increased free and total testosterone in both sedentary men and taekwondo athletes, with larger increases in those who trained.^[8] It is a single small study, so it should not be read as proof that magnesium raises testosterone.

Safety. The US tolerable upper intake level for supplemental magnesium is 350 mg per day, set because high doses can cause diarrhea. This limit is under debate.^[9] People with kidney problems should not take magnesium supplements without medical advice. For more, see our zinc and magnesium guide.

Zinc

Testosterone. Zinc is the best-supported mineral on this list, mainly when intake is low. In a small study, restricting dietary zinc for 20 weeks lowered serum testosterone in four young men, and six months of zinc supplementation raised it in nine marginally zinc-deficient older men.^[10] That tells us zinc matters if you are low, not that extra zinc boosts testosterone in men with normal zinc status.

Sleep. We did not find strong trial evidence that zinc supplements improve sleep in men with normal zinc status.

Safety. The FDA tolerable upper limit for adults is 40 mg per day (the European Food Safety Authority uses 25 mg). Excess zinc can cause anemia, low white cell counts and zinc-induced copper deficiency.^[11] Most people get enough zinc from food, and blood testing with a doctor is the way to find out if you are low.

Ashwagandha

Ashwagandha (Withania somnifera) is an herb used in Ayurvedic medicine. It has the most trial data of any ingredient here, although the trials are small and short, and different trials use different branded extracts.

Sleep. A meta-analysis of five randomized trials (400 participants) found a small but significant effect on sleep, larger in adults with insomnia and in trials using 600 mg per day or more for at least 8 weeks. The authors said more safety data are needed for long-term use.^[12]

Testosterone. Results are mixed but interesting. In an 8-week crossover trial in overweight men aged 40 to 70, an extract was associated with a 14.7 percent greater increase in salivary testosterone than placebo, although fatigue, vigor and sexual well-being did not differ between groups.^[4] In an 8-week trial in 57 men doing resistance training, serum testosterone rose by 96.2 ng/dL with ashwagandha versus 18.0 ng/dL with placebo.^[13] A systematic review of herbs and testosterone concluded that ashwagandha and fenugreek extracts had positive effects, but that conclusions were limited by small samples and differences in doses and extracts.^[5]

Safety. Case reports describe liver injury linked to ashwagandha supplements, with jaundice appearing 2 to 12 weeks after starting; liver tests normalized within 1 to 5 months in four of the five patients.^[14] Stop use and see a doctor if you develop yellow skin or eyes, dark urine, itching or abdominal pain. Check with a doctor first if you have a liver, thyroid or autoimmune condition, take sedatives or other medication, or are pregnant. See also our testosterone supplements guide.

Glycine

Glycine is an amino acid. In a 3-night study of healthy volunteers whose sleep was restricted by 25 percent, 3 g of glycine before bed reduced next-day fatigue and improved a vigilance test compared with placebo.^[15]

We are not aware of trials showing glycine changes testosterone. Any link would be indirect, through better sleep, and is unproven. For how sleep stages relate to hormones, see our guide to sleep stages and testosterone.

Tart Cherry

Tart (Montmorency) cherries contain some melatonin. In a crossover trial of 20 healthy volunteers, a week of tart cherry juice concentrate raised urinary melatonin and was associated with longer time in bed, longer total sleep time and higher sleep efficiency.^[16] No trial we know of links tart cherry to testosterone. Juice also contains sugar, so check labels if you watch your calorie intake or blood sugar.

L-Theanine

L-theanine is an amino acid found in tea. In a crossover trial of 30 healthy adults, 200 mg per day for four weeks lowered sleep latency and sleep disturbance sub-scores on a sleep quality questionnaire, along with depression and anxiety scores.^[17] The trial was small and did not measure testosterone or cortisol, so claims that L-theanine supports testosterone by lowering cortisol are not backed by the research we reviewed. See our stress and testosterone guide for the broader picture.

Melatonin

Melatonin is a hormone that signals night to your body clock. A meta-analysis of 19 randomized trials (1,683 people with primary sleep disorders) found it shortened sleep latency by about 7 minutes and increased total sleep time by about 8 minutes. The authors described the effects as modest.^[6]

Does it lower testosterone? The small human data we found do not show that. In a double-blind, placebo-controlled trial, six healthy men took 6 mg of melatonin daily for one month, and nocturnal testosterone, LH and FSH secretion did not change.^[18]That is a small, short study, so it cannot rule out effects in other groups or at other doses.

Quality problem. A laboratory analysis of commercial supplements found melatonin content ranging from 83 percent below to 478 percent above the label, and about a quarter contained serotonin.^[7] If you use melatonin, choose a product with third-party testing and talk to a doctor, especially for long-term or nightly use, or if you take other medications.

What to Avoid: Habits That Work Against Sleep

Alcohol. A review of studies in healthy volunteers found alcohol shortens the time to fall asleep but increases sleep disruption in the second half of the night and, at moderate and high doses, reduces total REM sleep.^[19] See our alcohol and testosterone guide.

Caffeine. Caffeine can stay active in the body for hours. If your sleep is poor, try moving your last coffee or caffeinated drink earlier in the day.

Cannabis. Research on cannabis and sleep is limited and mixed, and relying on it as a long-term sleep aid is not something we recommend. Talk to a doctor if you use it to sleep.

Sedating sleep medicines. Over-the-counter products containing diphenhydramine or doxylamine are medicines rather than supplements. Product labels warn about drowsiness, and they are not intended for regular long-term use. Ask a pharmacist or doctor before using them.

Before You Start Any Supplement

How Thrive Helps

Thrive is a wellness app that helps you build habits such as a steady bedtime and an evening wind-down alongside your training and nutrition routines. It is not a medical device and does not diagnose or treat any condition. Learn more about Thrive.