Yu Sleep Ingredients: What Each of the 10 Ingredients Does for You, With Doses and Evidence

Yu Sleep supplement facts label

You are looking at the most transparent version of this label so far. In August 2026 the manufacturer published an updated panel that disclosed the melatonin amount for the first time. This is the current panel. Inactive ingredients are purified water, vegetable glycerin, natural flavor and citric acid, so you get a liquid without sugar, gelatin or coloring. We track the label history in our report on the Yu Sleep formula update.

† Daily Value not established. Ingredients in a proprietary blend are listed in descending order by weight, so tart cherry concentrate is the largest component and GABA the smallest.

Why the proprietary blend matters to you

A 637 mg blend across seven ingredients averages about 90 mg each, but the real distribution is uneven. Tart cherry concentrate, listed first, probably accounts for a large share. That leaves less room for magnesium glycinate, which is bulky (glycinate is only about 14% elemental magnesium). A clinically studied 200 mg dose of L-theanine plus 100–300 mg of GABA plus a meaningful magnesium dose would exceed 637 mg on their own.

The practical conclusion: Yu Sleep almost certainly gives you lower doses of some ingredients than the studies below used. That does not mean it does not work. Ingredients that act on the same calming pathways can add up, and the sublingual route improves absorption of small doses. But it does mean you should judge the product on how it works for you over three to four weeks, not on ingredient studies alone. We say this plainly because a brand that hides doses asks you to trust it; the 60-day guarantee is what makes that trust reasonable.

Ingredient-by-ingredient breakdown

1. Melatonin (0.9 mg)

What you get: a natural "lights out" signal without the hangover. Melatonin is the hormone your pineal gland releases when it gets dark. It does not sedate you; it tells your brain that night has started and shifts your circadian clock.

Evidence: A widely cited MIT study led by Richard Wurtman found that 0.3 mg restored normal sleep in older adults, while higher doses raised blood levels far above the physiologic range and were linked to next-day hangover. Meta-analyses show melatonin shortens time to fall asleep by about 7 minutes and increases total sleep by around 8 minutes on average, with larger effects for circadian problems like jet lag and delayed sleep phase.

Why 0.9 mg works in your favor: It sits between the 0.3 mg physiologic dose and the 1–3 mg range that most clinical trials use, and well below the 5–10 mg in typical gummies. This is the main reason Yu Sleep users report less grogginess. We compare the doses in low dose melatonin vs high dose and look at Yu Sleep vs sleep gummies for dose accuracy and sugar.

2. Magnesium glycinate

What you get: a relaxed body and a calmer stress response. Magnesium regulates GABA receptors, lowers cortisol and relaxes muscle. Glycine, the amino acid it is bound to, has sleep benefits of its own: 3 g of glycine before bed improved sleep quality and reduced daytime fatigue in Japanese trials.

Evidence: A randomized trial in older adults with insomnia found that 500 mg of magnesium daily for eight weeks improved sleep time, sleep efficiency and time to fall asleep, and lowered cortisol. About half of Americans do not get enough magnesium from food, which is why it appears in almost every serious sleep formula.

Dose note: The trial dose (500 mg of magnesium oxide, roughly 300 mg elemental) is far more than could fit in Yu Sleep's blend. Expect a modest contribution, not a full magnesium supplement. If you are deficient, a separate product may still be worthwhile; we rank the forms in our guide to the magnesium glycinate vs threonate for sleep.

3. GABA (gamma-aminobutyric acid)

What you get: help switching off at lights-out. GABA is the brain's main inhibitory neurotransmitter. Benzodiazepines and Z-drugs work by boosting GABA signaling. Oral GABA cannot cross the blood-brain barrier easily, so its effect may work through the gut-brain axis instead.

Evidence: A 2016 Japanese trial found 100 mg of oral GABA reduced time to fall asleep by about 5 minutes and increased early-night deep sleep compared with placebo. A 2019 study combining GABA with L-theanine found the pair worked better together than either alone in animal models, which is a point in favor of a formula that includes both.

4. L-theanine

What you get: calm without drowsiness. L-theanine, the amino acid that makes green tea calming despite its caffeine, raises the alpha brain-wave activity associated with relaxed alertness and increases GABA, serotonin and dopamine in the brain.

Evidence: A 2019 randomized trial in healthy adults found 200 mg daily for four weeks reduced stress scores and improved sleep quality ratings. In children with ADHD, 400 mg improved sleep efficiency on actigraphy. L-theanine does not cause drowsiness, which makes it a good fit for a formula that promises you no grogginess.

5. 5-HTP (5-hydroxytryptophan)

What you get: support for your own serotonin and melatonin production over time. 5-HTP is one step away from serotonin in the tryptophan pathway. Serotonin is then converted to melatonin at night. Raising 5-HTP can therefore support both mood and your body's own melatonin output, which is the slow-building part of the formula.

Evidence: Small studies show 5-HTP increases REM sleep and, combined with GABA, shortens time to fall asleep. Doses in trials range from 50 to 300 mg. Yu Sleep's amount is not disclosed but is likely at the lower end given the blend size. Does 5-HTP help you sleep? We weigh the trials in 5-HTP vs melatonin.

Warning: 5-HTP should not be combined with SSRIs, SNRIs, MAOIs, tramadol, triptans or St. John's wort without medical advice because of the risk of serotonin syndrome. We cover 5-HTP and SSRIs in detail, and every other drug class in our guide to Yu Sleep interactions.

6. Apigenin

What you get: chamomile's calming effect in a concentrated form. Apigenin is the flavonoid responsible for chamomile's reputation. It binds to benzodiazepine sites on GABA-A receptors, producing mild anxiolytic effects without the sedation or dependence of drugs that act on the same receptor.

Evidence: A 2017 trial of chamomile extract in adults with generalized anxiety found meaningful symptom reduction over eight weeks. Research on isolated apigenin at 50 mg is mostly preclinical but popular in biohacking "sleep stacks."

7. Lemon balm extract

What you get: a longer-lasting calm. Lemon balm (Melissa officinalis) inhibits the enzyme that breaks down GABA, so GABA stays active longer. It has been used for nervous tension since the Middle Ages.

Evidence: A 2011 pilot study found 600 mg of lemon balm extract reduced anxiety symptoms by 18% and insomnia by 42% in stressed volunteers. Combined with valerian it improved sleep quality in a randomized trial of menopausal women.

8. Red tart cherry juice concentrate

What you get: a food source of melatonin plus anti-inflammatory support. Montmorency tart cherries are one of the few foods that naturally contain melatonin, plus anthocyanins that reduce inflammation and tryptophan-degrading enzymes.

Evidence: A 2012 crossover trial found tart cherry juice raised urinary melatonin, increased total sleep time by 25 minutes and improved sleep efficiency. A 2018 pilot in older adults with insomnia showed 84 more minutes of sleep on polysomnography. Tart cherry is the largest component of Yu Sleep's blend. If you have seen the viral "cherry trick" videos, we examine Yu Sleep cherry trick separately.

9. Vitamin B6 (0.5 mg)

What you get: the cofactor that lets the rest of the formula work. B6 converts 5-HTP to serotonin and glutamate to GABA. It is included to make the other ingredients work, not for its own sleep effect. There is also some evidence that B6 increases dream recall, which may explain the vivid dreams some users mention. We look at the vitamin B6 sleep research alongside 5-HTP.

10. Vitamin B2 (0.5 mg)

What you get: support for energy metabolism and tryptophan conversion. At 0.5 mg riboflavin is a supporting player. Do not expect it to change your sleep on its own.

Evidence quality summary

Use this table to set your expectations. The strongest evidence belongs to melatonin; the rest ranges from moderate to limited.

What Yu Sleep does not contain

You avoid the ingredients that cause the classic "PM" hangover. Yu Sleep is free of valerian, diphenhydramine (the antihistamine in ZzzQuil and Tylenol PM), doxylamine, CBD, kava and any prescription-only compound. According to the manufacturer it contains no gluten, dairy, soy or artificial colors. It is not certified organic or third-party tested by NSF or USP, which we note as a transparency gap you should weigh.

How Yu Sleep compares to other sleep formulas

The ingredient profile is close to what sleep researchers and biohackers often recommend as a "sleep stack": magnesium glycinate, L-theanine, apigenin and low-dose melatonin. What Yu Sleep adds for you is GABA, 5-HTP, lemon balm and tart cherry, plus a liquid delivery you can adjust drop by drop. Compared with a typical melatonin gummy, you get one-tenth the melatonin and nine more actives. Compared with a "PM" antihistamine product, it works through calming pathways rather than blocking histamine, which is why it does not cause the dry mouth and hangover those products are known for.

What users actually report after taking this combination for a month is covered in our Yu Sleep reviews and complaints. How to take it so the fast-acting and slow-building ingredients both do their job is in our Yu Sleep instructions guide.

See the current Yu Sleep offer

You can test the full formula for two months with your money protected. Bundle pricing and the 60-day guarantee are only available on the official website.

Frequently asked questions