Pulsed electromagnetic-field device,
does it really help with Improvement of insomnia symptoms?
research showsThe grade is C. In a 153-participant multicenter double-blind randomized trial, week-4 Insomnia Severity Index scores were 7.13 with the active device and 11.07 with sham. The reported between-group effect reached Cohen d 0.86. The manufacturer funded the study and supplied the device, while the trial was under 200 participants, lasted four weeks, and measured no objective treatment outcome.
ads claimVerdict 1386 is D with 34 points for knee osteoarthritis; this verdict concerns insomnia symptoms. Results from different indications were not combined merely because both use the PEMF label.
Useful facts when choosing a product
- The system generated 1-Hz pulses under the head and used a wrist monitor algorithm to stop stimulation after sleep onset.
- The paper states: “This study is sponsored by BestCare & SuMian BioTech Co., Ltd., who also provided the PMTS.”
- The authors declared no potential conflicts and stated that the sponsor had no role in analysis, interpretation, or scientific writing.
Chamgap Semantic Classification Code
Candidate index · review held
UNK.low-frequency-pulsed-magnetic-therapy-system-used-at-bedtime.UNK.insomnia-symptoms.improve.shamUnknown > low-frequency pulsed magnetic therapy system used at bedtime > Unknown > insomnia symptoms > Improvement claim > Sham procedure or device
An automated migration candidate, not an issued permanent code; exact claim scope remains under review. This machine-generated migration candidate helps retrieval but is not a permanent assignment. The original verdict ID and URL remain authoritative.
What the research actually shows
Liao and colleagues randomized 153 adults at three sleep centers to active PMTS, 76 participants, or sham, 77 participants. The study included one baseline week, four treatment weeks, and one follow-up week. Sham emitted mild heat but no magnetic field. The primary outcome was weekly patient-reported ISI; secondary outcomes were PSQI and sleep-diary latency, efficiency, actual sleep time, and wake after sleep onset. No actigraphy or treatment-effect polysomnography was included. Missing values were multiply imputed.
Why this is classified as C (50)
Moderate-to-large patient-reported effects came from a 153-participant, four-week manufacturer-funded trial, giving C with 50 points.
Counterpoint. Objective sleep effects and long-term durability remain unconfirmed.
Rejudgment record. Cross-check applied — Moderate-to-large patient-reported effects versus sham, limited by manufacturer funding, small sample, and short duration
| Endpoint | P | Symptom or function itself is the target - including patient reports and performance tests |
| Replication | R1 | Single confirmatory trial |
| Independence | I0 | Evidence comes only from manufacturer studies |
| Effect size | E+ | Meets the clinically important threshold |
Stored derived and displayed grades match; this is not a current recalculation or validity check (C).
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 |
|---|---|---|
| Improvement in patient-reported insomnia symptoms | C | Between-group ISI and PSQI effects were moderate to large, but evidence is manufacturer-only. |
| Improvement in actigraphy or polysomnography sleep outcomes | ? | The pivotal PMTS trial did not measure efficacy with objective sleep testing. |
Cross-check — AI research and Codex final gate
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Liao J et al., 2023 | Multicenter double-blind randomized sham-controlled trial | 153 randomized with multiple-imputation analysis, 76 versus 77 | BestCare & SuMian BioTech Co., Ltd. sponsored the study and provided the PMTS | Weekly ISI primary outcome; PSQI and sleep-diary secondary outcomes | Week-4 ISI 7.13±0.50 versus 11.07±0.51; the article did not define the type of the ± values. Reported between-group d 0.86, P<0.001. PSQI between-group d 0.58. | Pivotal direct randomized trial |
Receipt — 2 References
All 2 cited sources were verified for existence at the original page (as of 2026-08-07).
Final verification and publication gate: Codex · Evidence date: 2026-08-07 · Corrections: none
Cite this verdict
[Chamgap] Pulsed electromagnetic-field device x insomnia — Evidence Grade C·50. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/sleep/pulsed-electromagnetic-field-device-insomnia/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.