Quantitative Study on the Efficacy of Acupuncture in the Treatment of Menopausal Hot Flashes and Its Comparison with Non-Hormonal Drugs
Li et al. · Research Square · 2020
Evidence Level
MODERATEOBJECTIVE
To quantitatively compare the efficacy of acupuncture with sham acupuncture, placebo, and non-hormonal drugs in the treatment of menopausal hot flashes
WHO
1,123 women in natural menopause or with a history of breast cancer, with a mean age of 54 years
DURATION
Treatments from 4 to 24 weeks, median 8 weeks
POINTS
Variable according to the individual protocols of the studies included in the meta-analysis
🔬 Study Design
Traditional Acupuncture
n=631
Traditional manual acupuncture
Electroacupuncture
n=69
Acupuncture with electrical stimulation
Sham Acupuncture
n=423
Placebo acupuncture (control)
📊 Results in numbers
Hot flash reduction - Electroacupuncture
Hot flash reduction - Traditional Acupuncture
Hot flash reduction - Sham
Hot flash reduction - Oral placebo
📊 Outcome Comparison
Hot flash reduction at week 8 (episodes/day)
This study shows that acupuncture can be an effective option for reducing menopausal hot flashes. Electroacupuncture demonstrated results comparable to antidepressant medications used for this purpose, but without the common side effects of those drugs. This offers a safe alternative for women who cannot or do not wish to use hormones.
Article summary
Plain-language narrative summary
This study represents a comprehensive quantitative analysis of the efficacy of acupuncture in the treatment of menopausal hot flashes, including 17 randomized controlled trials with 1,123 participants. The researchers used a sophisticated methodology called model-based meta-analysis (MBMA) to overcome limitations of previous studies and provide more precise evidence on the effectiveness of acupuncture.
The clinical context is important: hot flashes affect approximately 75% of menopausal women in the United States, significantly impacting quality of life. Although hormone replacement therapy is effective, it has contraindications for women with a history of breast cancer, thromboembolism, or cardiovascular disease. Available non-hormonal alternatives, such as antidepressants (paroxetine, other SSRIs/SNRIs) and anticonvulsants (gabapentin), have limited efficacy and considerable side effects.
The study methodology was rigorous. The researchers conducted a comprehensive search of five major databases, including only randomized controlled trials comparing traditional acupuncture, electroacupuncture, or sham acupuncture (placebo) in women in natural menopause or with a history of breast cancer. The mathematical model developed considered important factors such as treatment duration and baseline hot flash frequency, allowing for more precise comparisons across different interventions.
The main results revealed important differences between types of acupuncture. After correction for a baseline of 8 hot flashes per day, electroacupuncture proved more effective than traditional acupuncture, reducing hot flashes by 3.6 episodes/day compared with 3.1 episodes/day for traditional acupuncture at week 8 of treatment. Both were superior to sham acupuncture (2.6 episodes/day) and significantly better than oral placebo (2.3 episodes/day).
A clinically relevant finding was that the efficacy of electroacupuncture was comparable to that of SSRI/SNRI antidepressants and anticonvulsants such as gabapentin, which are commonly prescribed off-label for hot flashes. This is particularly significant given that these drugs frequently cause side effects such as insomnia, nausea, dry mouth, dizziness, and fatigue, in addition to potentially problematic drug interactions, especially in women with breast cancer using tamoxifen.
The study identified that baseline hot flash frequency significantly influences treatment efficacy — for each increase in baseline frequency, the maximum effect increased 0.343-fold. This finding helps explain the heterogeneity observed in previous studies and provides a basis for treatment personalization. In addition, electroacupuncture showed lower inter-individual variability (30%) compared with traditional acupuncture (40%), possibly due to standardization of electrical stimulus versus the variability of manual stimulation.
The clinical implications are substantial. For patients seeking non-pharmacologic alternatives or who cannot use hormones, acupuncture, especially electroacupuncture, offers a therapeutic option with efficacy comparable to conventional drugs but potentially with fewer adverse effects. Studies suggest that acupuncture may provide additional benefits such as improved sleep quality and reduced fatigue.
Limitations include variability in baseline hot flash frequency across studies, different point protocols used (which could not be analyzed separately due to limited sample size), and inclusion only of studies published in English. Subjective assessment of hot flash frequency by the patients themselves may also introduce variability in the results.
In conclusion, this study provides robust evidence that acupuncture, particularly electroacupuncture, represents an effective therapeutic option for menopausal hot flashes, with efficacy comparable to available non-hormonal drugs but potentially with a more favorable safety profile. These findings support the inclusion of acupuncture in treatment guidelines for menopausal vasomotor symptoms.
Strengths
- 1Sophisticated methodology with model-based meta-analysis that controls for heterogeneity across studies
- 2Robust sample of 1,123 participants from 17 randomized controlled trials
- 3Correction for important confounders such as baseline hot flash frequency and treatment duration
- 4Direct comparison with established non-hormonal drugs
- 5Separate analysis of different types of acupuncture (traditional vs. electroacupuncture)
Limitations
- 1Heterogeneity in baseline hot flash frequency across included studies
- 2Inability to analyze different point protocols due to limited sample size
- 3Inclusion only of studies published in English, potential publication bias
- 4Subjective assessment of hot flashes by patients themselves may introduce variability
- 5Only 4 electroacupuncture studies included, requiring more research for confirmation
Expert Commentary
Prof. Dr. Hong Jin Pai
PhD in Sciences, University of São Paulo
▸ Clinical Relevance
Management of menopausal hot flashes represents a daily clinical challenge, especially when facing populations who cannot receive hormone replacement therapy — women with a history of breast cancer, thromboembolism, or established cardiovascular disease. Available non-hormonal alternatives, such as paroxetine, venlafaxine, and gabapentin, carry adverse-effect profiles that often limit adherence: insomnia, nausea, sedation, and, specifically in breast cancer survivors using tamoxifen, clinically relevant pharmacologic interactions. This work, by quantifying the efficacy of electroacupuncture at 3.6 hot flash episodes per day in reduction and demonstrating practical equivalence with SSRIs and anticonvulsants, positions acupuncture as a concrete alternative in the therapeutic arsenal — not as a second-line complementary resource, but as a primary option for specific populations where other interventions are contraindicated or poorly tolerated.
▸ Notable Findings
The distinction between electroacupuncture and traditional acupuncture deserves special attention: 3.6 versus 3.1 daily episodes of reduction, with electroacupuncture showing lower inter-individual variability — 30% versus 40% for manual acupuncture. This finding suggests that standardization of electrical stimulus confers greater therapeutic consistency, which has direct implications for the predictability of outcome over the course of treatment. Another striking finding is the relationship between baseline hot flash frequency and response magnitude: for each additional unit at baseline, the maximum effect increases 0.343-fold. This means that patients with more symptomatic profiles tend to show greater absolute gains — information that qualifies the selection of ideal candidates for treatment. The superiority of both traditional acupuncture and electroacupuncture over sham reinforces a specific effect beyond the placebo component.
▸ From My Experience
In my practice, I have advised colleagues who refer perimenopausal patients not to underestimate the speed of response of electroacupuncture: I usually observe perceptible reduction in hot flash frequency as early as between the third and fifth session, which greatly favors adherence. The protocol we use in the Acupuncture Group at the Pain Center usually involves eight to twelve sessions in the acute phase, with biweekly or monthly maintenance according to individual response. The profile that responds best, consistent with what this work indicates, is the patient with frequent and intense hot flashes — above six to eight episodes per day — and who has contraindications to or intolerance of pharmacologic options. We frequently combine sleep hygiene guidance and autonomic regulation techniques. For breast cancer survivors using tamoxifen, electroacupuncture has become, in our service's practice, the effective first-line option available, and the results we have observed over the years are consistent with the magnitudes reported in this meta-analysis.
Full original article
Read the full scientific study
Research Square · 2020
DOI: https://doi.org/10.21203/rs.3.rs-90756/v1
Access original articleScientific Review
Marcus Yu Bin Pai, MD, PhD
CRM-SP: 158074 | RQE: 65523 · 65524 · 655241
PhD in Health Sciences, University of São Paulo. Board-certified in Pain Medicine, Physical Medicine and Rehabilitation, and Medical Acupuncture. Scientific review and curation of every entry in this library.
Learn more about the author →Medical disclaimer: This content is for educational purposes only and does not replace consultation, diagnosis, or treatment by a qualified professional. Some information may be assisted by artificial intelligence and is subject to inaccuracies. Always consult a physician.
Content reviewed by the medical team at CEIMEC — Integrated Centre for Chinese Medicine Studies, a reference in Medical Acupuncture for over 30 years.
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