Open Source Apothecary At Home / Foundations
Publication bias, and the herbal literature's positive-results problem
Positive trials get published. The absence of negative trials is not the presence of positive ones.
guide
A trial that finds nothing is harder to publish than a trial that finds
something, and in complementary medicine the asymmetry is worse than in drug trials because
a substantial share of the research is funded by the industry that sells the product, is
published in journals that specialise in the field, and is small. The consequence is that
the body of literature on any popular herb is tilted positive before anyone reads it.
Three signs that a given claim should be held loosely:
- Only small, single-centre trials. Small trials have large random swings and are the
- A systematic review that says the evidence quality is low or very low. That phrase
- Effect sizes larger than the drug the plant is compared against. Curcumin trials
Systematic reviews are the corrective, and they are why every remedy page here leads with
them. Where a review exists, its verdict is quoted verbatim, including when the verdict is
that the evidence is too poor to conclude anything.
What the studies found
Meta-Analysis2025The Cochrane database of systematic reviews
Stimulation of the wrist acupuncture point PC6 for preventing postoperative nausea and vomiting: a network meta-analysis.
NMAs suggest that both invasive and noninvasive PC6 acupoint stimulation combined with antiemetics may reduce PON and POV, compared to sham, and likely lower rescue antiemetic use.
PubMed 40938065 ↗
Meta-Analysis2024Journal of ethnopharmacology
Herbal medicine for Hashimoto's thyroiditis: A systematic review and network meta-analysis.
Herbal medicines may be effective in the treatment of HT, especially in reducing thyroid antibody levels and improving clinical symptoms without affecting thyroid function.
PubMed 38181936 ↗
Meta-Analysis2024Complementary therapies in medicine
Clinical effects of Hibiscus sabdariffa Linn. on obesity treatment: A systematic review and meta-analysis of randomized controlled trials.
Our study did not show a clinical benefit of H. sabdariffa extract in obesity treatment.
PubMed 38878905 ↗
Meta-Analysis2023Medicine
Acupuncture combined with Chinese herbal medicine in the treatment of perimenopausal insomnia: A systematic review and meta-analysis.
The current analysis results show that acupuncture combined with Chinese medicine seems to have a more positive effect than western medicine alone in improving sleep and FSHF in PMI patients, but no difference has been found in improving E2 and LH.
PubMed 37960761 ↗
Meta-Analysis2022Phytomedicine : international journal of phytotherapy and phytopharmacology
Acupuncture for cancer-related conditions: An overview of systematic reviews.
Evidence from SRs showed that acupuncture is beneficial to cancer survivors with cancer-related pain, fatigue, insomnia, improved quality of life, nausea and vomiting, bone marrow suppression, menopausal symptoms, arthralgia, and dysphagia, and may also be potential for lymphoedema, gastrointestinal function, and xerostomia.
PubMed 36099656 ↗Cautions and interactions
- A product page is not evidence. Neither is a book, including this one.
- Funding and conflicts are worth checking on any trial cited in support of a
product you are about to buy.
Related
Sources
- Stimulation of the wrist acupuncture point PC6 for preventing postoperative nausea and vomiting: a network meta-analysis. The Cochrane database of systematic reviews 2025; doi:10.1002/14651858.CD003281.pub3 PubMed 40938065
- Herbal medicine for Hashimoto's thyroiditis: A systematic review and network meta-analysis. Journal of ethnopharmacology 2024; doi:10.1016/j.jep.2023.117663 PubMed 38181936
- Clinical effects of Hibiscus sabdariffa Linn. on obesity treatment: A systematic review and meta-analysis of randomized controlled trials. Complementary therapies in medicine 2024; doi:10.1016/j.ctim.2024.103063 PubMed 38878905
- Acupuncture combined with Chinese herbal medicine in the treatment of perimenopausal insomnia: A systematic review and meta-analysis. Medicine 2023; doi:10.1097/MD.0000000000035942 PubMed 37960761
- Acupuncture for cancer-related conditions: An overview of systematic reviews. Phytomedicine : international journal of phytotherapy and phytopharmacology 2022; doi:10.1016/j.phymed.2022.154430 PubMed 36099656