Heukharang lettuce extract,
does it really help with Improved sleep quality and sleep onset?
research showsA four-week double-blind trial that randomized 100 adults with poor sleep quality found improvements in the global PSQI score and actigraphic and polysomnographic total sleep time and sleep efficiency. The overall grade is C because only 91 participants were analyzed, most were women, the study was company-funded and unreplicated, and sleep-onset results were not clearly significant.
ads claimMarketing may convert a higher lactucin content than ordinary lettuce into claims of insomnia treatment, immediate sleep onset, or replacement of hypnotics. Direct human evidence is a four-week adjunctive trial in adults with poor sleep quality, not patients diagnosed with a sleep disorder.
Useful facts when choosing a product
- The human-trial formulation was Heukharang lettuce extracted with 30% ethanol for four hours and freeze-dried, delivering 1,000 mg/day of extract.
- MFDS individual recognition No. 2025-21 specifies a daily intake of 1,000 mg.
- Participants took two capsules containing 500 mg of extract each, 30 minutes before bedtime for four weeks.
- Heukharang fresh produce, tea, powder, jelly, and liquid products are sold in South Korea, but extraction method, Heukharang content, and lactucin standardization may differ from the study product.
- A general food containing Heukharang is not necessarily equivalent to a health functional food or the clinical-trial formulation.
What the research actually shows
Son and colleagues in 2025 tested the formulation recognized by MFDS as No. 2025-21 at 1,000 mg/day for four weeks, randomizing 100 adults and analyzing 91. Global PSQI was marginal at -0.93 versus placebo, p=0.0462, while actigraphic and polysomnographic total sleep time and efficiency and polysomnographic wake after sleep onset were positive. The PSQI sleep-latency component was null at p=0.0991, and ISI was also null. Uni Bio funded the study and supplied the products, making this a single-product trial. The 2023 rodent electroencephalographic and GABA data do not replicate human sleep-onset efficacy.
Why this is classified as C (56)
Global PSQI was marginal at -0.93, p=0.0462, while actigraphic and polysomnographic total sleep time, efficiency, and wake after sleep onset were positive. This remains one company-funded four-week trial with 91 analyzed participants and no independent replication; PSQI sleep latency at p=0.0991 and ISI were null, resulting in C with 56 points.
Counterpoint. A short-term signal for sleep duration and efficiency remains for the exact 30% ethanol extract at 1 g/day.
Rejudgment record. Reassessment (cross-check reflected) — The four-week trial of MFDS No. 2025-21 at 1,000 mg/day randomized 100 and analyzed 91 participants; global PSQI was -0.93 at p=0.0462 and objective duration, efficiency, and wake after sleep onset were positive, but PSQI sleep latency at p=0.0991 and ISI were null and this was one company-funded product without independent replication
Sub-claim grades by effect
This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.
| Effect (sub-claim) | Grade | Basis |
|---|---|---|
| Sleep duration and sleep efficiency | C | One four-week RCT was positive for global PSQI and selected actigraphic and polysomnographic measures. |
| Sleep onset | D | Null PSQI sleep-latency and ISI findings. |
Cross-check — Codex and Claude
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Son K et al. 2025 | Randomized double-blind placebo-controlled trial | 4 | Funded by Uni Bio, which also supplied the study products | PSQI, ISI, actigraphy, and subset polysomnographic total sleep time, efficiency, and wake after sleep onset | Global PSQI was marginal at -0.93, p=0.0462, and actigraphic and polysomnographic total sleep time, efficiency, and wake after sleep onset were positive, but PSQI sleep latency at p=0.0991 and ISI were null. | Key, single product |
| Ahn Y et al. 2023 | Rodent sleep and electroencephalographic mechanistic study | Included Medience-affiliated authors | Sleep time, non-rapid eye movement sleep, delta waves, and GABA receptors | Heukharang leaf extract increased sleep time and non-rapid eye movement sleep in rodents and showed GABA-receptor-related activity. | Preclinical support |
Receipt — 2 References
All 2 cited sources were verified for existence at the original page (as of 2026-07-15).
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-15 · Corrections: none
Cite this verdict
[Chamgap] Heukharang lettuce extract × Improved sleep quality and sleep onset — Evidence Grade C·56. 2 cited sources checked. Source: https://health-receipt.pages.dev/en/verdicts/sleep/heukharang-lettuce-extract/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
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