How much lemon balm is in Yu Sleep?

Not disclosed. It is one of seven ingredients inside the undisclosed 637 mg 'Proprietary Blend,' listed fourth by weight if the label complies with US labeling rules.

Does lemon balm stop 3 AM waking, like the ad says?

No study shows that. The claim, that it lowers cortisol enough to stop 3 AM waking, is unsupported; the one placebo-controlled trial of a lemon balm combination found no change in cortisol or in objectively measured night waking.

What does the research say about lemon balm and sleep?

Small trials at 400 mg to 3 g a day report better sleep scores, but most are open-label or unblinded, and a placebo-controlled combination trial found no benefit over placebo.

Is the '85% of participants' lemon balm claim from a real study?

Partly. The real study is Cases et al. 2011, an open-label pilot with no placebo, 20 stressed adults taking 600 mg a day for 15 days, published in Mediterr J Nutr Metab, not the journal the sales letter names.

Generally recognized as safe according to LiverTox, with no serious side effects reported in the trials reviewed here. Interaction data specific to lemon balm is thin, so treat it as unstudied rather than cleared, not as 'no interactions.'

Is a plain lemon balm supplement better than Yu Sleep?

It depends what you want. A standalone product lets you take a known, studied amount, 400 mg to 3 g a day; Yu Sleep's lemon balm sits at an undisclosed amount inside a blend with six other ingredients.

Lemon Balm in Yu Sleep: Dose, the Evidence, and Safety

Yu Sleep's Proprietary Blend lists lemon balm extract fourth of seven ingredients, with no amount disclosed, and the ad builds a "3 AM" promise on what this plant is supposed to do to cortisol, a claim our Yu Sleep reviews also checks against the product as a whole. Melatonin, vitamin B6 and vitamin B2 are the only 3 of Yu Sleep's 10 ingredients with a stated dose; lemon balm shares its undisclosed 637 mg blend with six others, a full breakdown covered on our Yu Sleep ingredients page. This page checks what lemon balm actually does for sleep, what the human studies behind it show, and whether Yu Sleep's dose can plausibly match them.

The table below summarizes lemon balm's position in Yu Sleep before the detail that follows.

Disclosed dose	Studied range	Blend ceiling (if listed by weight)	Evidence strength
Not disclosed (inside the blend)	400 mg to 3 g a day	up to about 159 mg	Weak

What lemon balm does for sleep

Lemon balm, from the plant Melissa officinalis, has a long history in traditional medicine for nervousness, anxiety, insomnia and menstrual irregularities, according to LiverTox, the drug and herbal hepatotoxicity database maintained by the National Institute of Diabetes and Digestive and Kidney Diseases. Researchers think part of its calming effect may come from rosmarinic acid, a compound in the plant that acts on GABA transaminase (GABA-T), an enzyme that breaks down the calming neurotransmitter GABA. Blocking that enzyme is the proposed mechanism, not a proven one: a 2024 study by Di Pierro and colleagues notes the effect "has not always been observed in a reproducible manner in humans." A related line of research on Cyracos, a specific lemon balm extract used in several sleep trials, describes it as containing "phytochemicals that inhibit gamma-aminobutyric acid catabolism" (Cases and colleagues, 2011), a similar GABA-related idea in different words. Both explanations describe a proposed pathway, not a confirmed one, and no trial has directly measured whether lemon balm changes GABA-T activity or GABA levels in the human brain. What the traditional use and the proposed mechanism do not establish is whether lemon balm, at any dose, meaningfully changes cortisol or middle-of-the-night waking, the specific claim behind Yu Sleep's "3 AM" hook, which the next section checks against the actual trials.

The evidence for lemon balm

Ingredient-evidence.md rates lemon balm's evidence for sleep as weak: the positive trials are small and mostly open-label or unblinded, and the one placebo-controlled trial that tested lemon balm inside a combination found no benefit. The table below lists every lemon balm sleep trial found in this review, plus one meta-analysis that measured anxiety and depression rather than sleep.

Study	Design, n	Dose	Result
Cases et al., 2011	Open-label, no placebo, n=20 stressed adults	600 mg/day Cyracos (300 mg morning, 300 mg before bed), 15 days	Insomnia score down 42%; 17 of 20 (85%) reached remission
Haybar et al., 2018	Randomized, placebo-controlled, n=80 angina patients	3 g/day, 8 weeks	Lower PSQI sleep-disturbance score than placebo
Di Pierro et al., 2024	Double-blind, crossover RCT, n=30 adults aged 18 to 65 with unrefreshing sleep	400 mg/day (2 x 200 mg Melissa phytosome tablets), 2 weeks per arm, 7-day washout	Insomnia Severity Index 6.8 vs 9.7 on placebo
Gutiérrez-Romero et al., 2024	Randomized, placebo-controlled, n=64, combination of L-theanine, lemon balm, valerian and saffron	6 weeks	No better than placebo on actigraphy sleep efficiency or the PSQI; salivary cortisol unchanged
Ghazizadeh et al., 2021 (meta-analysis, anxiety/depression, not sleep)	Meta-analysis of lemon balm trials for anxiety and depression	Varies by trial	Significant improvement vs placebo on both, no serious side effects

Weigh the Di Pierro trial's positive result against its conflict of interest: its lead author is the scientific director of the company that makes the tested Melissa phytosome product, and two co-authors consult for that company. No lemon balm trial, including Di Pierro's, measured night-time cortisol or 3 AM waking specifically, and the only trial that measured cortisol at all, Gutiérrez-Romero's combination study, found it unchanged after 6 weeks. That gap sits at the center of whether does Yu Sleep stop 3 AM wakeups, the specific promise the ad builds on lemon balm's supposed effect on cortisol.

The dose in Yu Sleep vs the study doses

The label does not say how much lemon balm Yu Sleep contains, and even the most generous ceiling sits well under every dose used in a lemon balm sleep trial. If the blend is listed by weight, as US rules require under 21 CFR 101.36(c)(2), lemon balm's ceiling as the fourth-listed of seven ingredients is about 159 mg, a figure that assumes the three ingredients listed above it, tart cherry, magnesium glycinate and apigenin, already take up most of the blend's 637 mg total. The lowest dose used in any lemon balm sleep trial was 400 mg a day, in Di Pierro's 2024 phytosome study, already more than double that 159 mg ceiling. The 600 mg/day dose behind the widely repeated "85%" figure from Cases 2011, and the 3 g/day dose in Haybar's 2018 angina trial, sit even further out of reach.

Lemon balm is not the only blend ingredient competing for space inside that 637 mg total. The lowest studied doses of four of the seven blend ingredients already add up close to the blend's entire size:

Lemon balm: 400 mg (Di Pierro 2024)
L-theanine: 50 mg
5-HTP: 50 mg
GABA: 100 mg
Combined: 600 mg, before tart cherry, magnesium glycinate and apigenin are even counted, inside a 637 mg blend

Lemon balm extract is also listed a second time on Yu Sleep's label, under "Other ingredients," alongside magnesium glycinate and apigenin, a duplication the label does not explain. Treat that repetition as a label oddity, not as evidence about how much lemon balm the blend actually contains.

Safety and interactions

Lemon balm has a good safety record in the trials reviewed here, though interaction data specific to it is thin. LiverTox calls lemon balm extracts "generally recognized as safe" and reports they "have not been linked to serum aminotransferase elevations… or to instances of clinically apparent acute liver injury." A 2021 meta-analysis of lemon balm trials for anxiety and depression by Ghazizadeh and colleagues found the herb improved symptoms "without serious side effects," though that meta-analysis measured anxiety and depression, not sleep. No interaction is documented in the sources checked for lemon balm, which is not the same as saying no interaction exists; treat it as unstudied rather than cleared.

A few groups have specific reasons for caution:

Anyone taking a sedative or sleep medication, since no trial tested lemon balm alongside one.
Anyone pregnant, breastfeeding or considering it for a child, since no trial studied those groups.
Anyone who wants a known, disclosed amount, since Yu Sleep's own lemon balm content and its extract ratio are not independently verified.

For the safety picture across all ten Yu Sleep ingredients, see Yu Sleep side effects.

Lemon balm alone vs lemon balm inside Yu Sleep

A standalone lemon balm supplement lets a buyer take a known, studied amount, anywhere from 400 mg to 3 g a day depending on the product; inside Yu Sleep, lemon balm's amount is fixed, undisclosed and bundled with nine other ingredients. The Cyracos extract used in the Cases 2011 and Gutiérrez-Romero combination trials is sold on its own at labeled doses; Yu Sleep's Proprietary Blend gives no comparable figure for lemon balm or for the six ingredients beside it. Lemon balm, magnesium glycinate and apigenin are the three of Yu Sleep's ten ingredients that also appear a second time under "Other ingredients," a labeling duplication with an unknown cause, while melatonin, vitamin B6 and vitamin B2 remain the only three of ten with a stated dose. No dedicated Yu Sleep-versus-lemon-balm comparison page exists on this site, since the two answer different questions: a standalone extract answers whether lemon balm itself works, while Yu Sleep bundles an undisclosed amount of it with nine other ingredients toward a broader sleep claim.

Bottom line

On lemon balm specifically, not on Yu Sleep as a whole, the evidence is weak but not nonexistent: small, mostly unblinded trials report better sleep scores at 400 mg to 3 g a day, while the one placebo-controlled combination trial found no benefit over placebo. The ad's specific promise, that lemon balm "reduces cortisol" so "you'll STOP waking up at 3 AM," is unsupported: no lemon balm trial measured night-time cortisol or 3 AM waking, and the one trial that did measure cortisol found no change after 6 weeks. The sales letter's "85%" figure is partly supported: it comes from a real study, Cases 2011, but that study was open-label with no placebo, 20 stressed adults, 15 days, published in Mediterr J Nutr Metab, not "Phytomedicine," the journal the sales letter names. Of the 14 readable buyer reports analyzed for this site, 64% report no noticeable effect and 14% report improved sleep, too small and too mixed a sample to credit or blame lemon balm specifically, which is the question our what buyers say about Yu Sleep piece answers for the product as a whole.

Lemon Balm in Yu Sleep