Chinese Herbal Medicine and Endometriosis

Summary

Chinese herbal medicine is a promising area of endometriosis research, with the strongest evidence suggesting potential benefits for pain relief and postoperative recovery, especially when used alongside conventional care. In published trials comparing combined treatment (Chinese herbal medicine plus conventional therapy) with conventional therapy alone, the combined approach was associated with greater pain reductions and fewer side effects, including a reduction in hot flushes. When Chinese herbal medicine was compared directly with hormonal therapies such as GnRH agonists, danazol and gestrinone, it was associated with fewer side effects, including fewer hot flushes and less irregular bleeding. Pain relief for Chinese medical interventions when used alone were generally comparable rather than clearly superior to conventional treatments.

This preliminary evidence is encouraging and growing, although most studies have been conducted in China, many have methodological limitations, and large definitive UK trials have not yet been completed.

Endometriosis can affect every aspect of a woman's life. From debilitating period pelvic pain to painful sex, low energy, compromised fertility, reduced ability to work and a reduction of overall well being.

For many women, support is not about choosing one path over another. It is about finding the combination that helps them feel better, function better and live more comfortably. National and international guidelines increasingly recognise the value of combining different treatment approaches for chronic conditions like endometriosis, and this principle underlies much of the research discussed here (Zondervan et al., 2020, New England Journal of Medicine).

That is one reason Chinese herbal medicine has attracted growing scientific interest in the treatment of endometriosis. Over the last decade, the evidence base has expanded from a handful of small studies into a larger body of peer-reviewed research, including placebo controlled randomised trials and meta-analyses.

The picture that is emerging is encouraging: Chinese herbal medicine may offer well tolerated, meaningful support in endometriosis, particularly for pain and postoperative care.

A Growing Research Base

One of the earliest major reviews in this area was the 2012 Cochrane review by Flower et al. At that point, only two randomised trials involving 158 women met the inclusion criteria. Those studies suggested symptom benefits comparable to gestrinone and at least as effective as danazol, with fewer side effects, but the evidence was too limited for firm conclusions.

Since then, the field has moved on substantially.

Newer research now includes:

• A multicentre double-blind placebo-controlled trial
• A large meta-analysis covering 34 randomised trials and 3,389 participants
• A focused postoperative meta-analysis of Salvia miltiorrhiza-containing formulas
• Post-surgical trials exploring recurrence, pregnancy and quality of life
• UK feasibility research showing that individualised Chinese herbal medicine can be tested rigorously against placebo in real-world practice

What the Evidence Says

Pain Support

Pain is one of the clearest areas of promise.

The broadest recent review, published in 2023 by Lin et al. in The American Journal of Chinese Medicine, analysed 34 randomised trials involving 3,389 participants. The review was registered on PROSPERO and followed Cochrane and PRISMA guidelines. Inclusion criteria required randomised controlled trials in women with confirmed endometriosis (by laparoscopy with histologic verification) and a defined pain measurement tool such as the Visual Analog Scale. Risk of bias was assessed using the Cochrane Collaboration tool: 75% of included trials had adequate randomisation, though 90% had unclear allocation concealment and none reported adequate blinding. The review did not apply a formal GRADE assessment to its outcomes. This means that while the findings are encouraging, they should be interpreted with some caution given the methodological limitations of the underlying trials.

The strongest signal emerged when Chinese herbal medicine was used alongside conventional treatment, with significant reductions in:

• Period pain
• Pelvic pain
• Pain during sex

This is an important pattern. It suggests Chinese herbal medicine may be particularly useful as a complementary approach within a wider treatment plan, rather than as an alternative.

When Chinese herbal medicine was used alone and compared directly with conventional therapies such as GnRH agonists, the picture was more mixed. A significant benefit was found for pelvic pain at the end of a three-month treatment period, but differences for period pain and pain during sex were not statistically significant.

Some benefits also appeared to continue after treatment stopped. Treatment durations in the included trials ranged from two to six months, and follow-up periods ranged from three to nine months after treatment ended. Benefits for period pain persisted for three months after treatment stopped but were not maintained at nine months. Even so, the short-term pain findings, particularly for combined treatment, are among the most encouraging in the research literature.

Better Tolerability Than Some Hormonal Treatments

One of the most consistent findings across the literature is tolerability.

Across trials and reviews, Chinese herbal medicine has repeatedly been associated with fewer side effects than some standard hormonal therapies, including GnRH agonists, danazol and gestrinone.

In the 2023 meta-analysis by Lin et al., two specific comparisons are relevant. When Chinese herbal medicine was used alone as an alternative to conventional therapy, it was associated with significantly fewer hot flushes and less irregular vaginal bleeding. When Chinese herbal medicine was added to conventional therapy and compared with conventional therapy alone, the combined treatment group experienced significantly fewer hot flushes. However, the pain outcomes in these comparisons differed: using Chinese herbal medicine alone showed comparable, rather than clearly superior, pain relief versus conventional therapy, while combined treatment showed more consistent advantages for pain.

For many people with endometriosis, tolerability matters just as much as symptom relief. A treatment only works in real life if it is something people can realistically stay with.

Postoperative Support and Recurrence

Post-surgical care is another especially promising area.

A 2022 meta-analysis by Gao et al. in Frontiers in Pharmacology looked specifically at formulas containing Salvia miltiorrhiza combined with GnRH agonist treatment after surgery, compared with GnRH agonist treatment alone. This is important because it narrows the focus from mixed herbal formulas to a more defined family of interventions, and evaluates them as a complement to standard postoperative care.

Across 10 randomised trials and 836 patients, the findings were striking. Compared with GnRH agonist treatment alone:

• Recurrence risk was reduced by 74% (RR 0.26, 95% CI 0.16–0.41)
• Pregnancy rates were nearly doubled, from around 26% to 51% (RR 1.96, 95% CI 1.58–2.44)
• CA-125 levels were lower
• Hot flashes and vaginal bleeding were less common

What makes this meta-analysis stand out is the consistency of the findings. For recurrence, pregnancy and adverse-event outcomes, heterogeneity was zero across the included trials (I² = 0%). The recurrence outcome was also rated high quality under GRADE assessment, which is unusual in this field. The pregnancy and adverse event outcomes were rated moderate quality. It is worth noting, however, that none of the included trials reported blinding or placebo controls, and all were conducted in China, which should be considered when interpreting these results.

Fertility Outcomes

Fertility is one of the most interesting areas of newer research.

The strongest single trial in the literature is a 2020 multicentre double-blind placebo-controlled study by Zhao et al., published in the Chinese Journal of Integrative Medicine, involving 202 women with endometriosis-associated infertility after surgery. Women received either matched placebo granules or a sequential Chinese herbal medicine protocol over six menstrual cycles. The trial used a central block randomisation system, sealed opaque envelopes for allocation concealment, and both participants and investigators were blinded. The study did not include a formal GRADE evaluation of its outcomes.

The results were encouraging:

• Clinical pregnancy rate was 44.6% in the herbal group vs 29.7% in placebo
• Live birth rate was 34.7% vs 20.8%
• Ovulation outcomes also improved
• Adverse events were similar between groups

What Makes This Area Scientifically Interesting

Researchers are not only looking at symptom scores. They are also exploring biological mechanisms that may help explain the clinical findings.

In the literature on Salvia miltiorrhiza-containing formulas, authors discuss anti-inflammatory activity, circulation-related effects and pain-pathway modulation. Lower CA-125 levels reported in postoperative trials suggest biological plausibility for Chinese herbs, as CA-125 is an established marker associated with endometriosis severity.

This does not turn herbal medicine into a shortcut or a miracle. But it does help explain why this field continues to attract serious research attention.

Long-Term Quality of Life

There is also early evidence that Chinese herbal medicine may have a role in longer-term management after surgery.

A 2021 randomised controlled trial by Ruan et al. in Reproductive and Developmental Medicine, involving 66 women with stage III–IV endometriosis (21 in the Chinese herbal medicine group, 21 receiving GnRH agonist, and 24 receiving oral contraceptives), found similar recurrence control across all three groups over a median follow-up of 22 months. However, sexual function, measured by the Female Sexual Function Index, was substantially better in the herbal group than in the GnRH agonist or oral contraceptive groups (OR 5.25 vs GnRHa; OR 3.94 vs OCs, both P = 0.00).

This is especially relevant in real life, because side effects and reduced quality of life are among the main reasons women stop long-term hormonal treatment.

It is a smaller and more preliminary study than the major meta-analyses, but it points to an important question: not just whether treatment controls recurrence, but how women actually feel while taking it.

Where We Are Today

Based on the published research, Chinese herbal medicine appears to have preliminary evidence of effectiveness in endometriosis-associated pain, especially when used alongside conventional care.

It also appears to have better tolerability than several standard hormonal comparators, with fewer side effects reported across trials and reviews.

Postoperative use is a particularly promising area, especially in studies involving Salvia miltiorrhiza-containing formulas, where recurrence and pregnancy findings have been notably strong when compared with GnRH agonist treatment alone.

And while research in fertility and long-term quality of life is still evolving, the results so far are strong enough to justify serious attention.

Large definitive trials with blinding and placebo control outside China, including in the UK, are still needed. The methodological limitations of much of the existing research — particularly around blinding, allocation concealment and the geographic concentration of trials — mean that the evidence, while substantial, should be interpreted with appropriate caution. But it is already enough to support genuine optimism, especially around pain, postoperative recovery, recurrence support and treatment tolerability.

Safety and Quality Matter

As with any herbal or supplement approach, quality matters. NHS guidance notes that herbal medicines can interact with medicines, may cause side effects and may not be suitable for everyone, including during pregnancy or before surgery. It also highlights that product quality can vary, particularly when products are bought online or by mail order.

So the most sensible approach is an informed one: choose carefully, and speak to a GP, pharmacist or specialist if you are taking medication, trying to conceive, pregnant, or preparing for surgery.

FAQ

Can Chinese herbal medicine help with endometriosis pain?

Research suggests it may. The strongest evidence is for endometriosis-associated pain, particularly when Chinese herbal medicine is used alongside conventional treatment. When used alone, it appears comparable to some hormonal treatments for certain pain types.

Is Chinese herbal medicine better tolerated than hormonal treatment?

Published trials and reviews consistently suggest it may be better tolerated than some hormonal comparators, with fewer hot flushes, less irregular bleeding and fewer treatment-related side effects reported in several studies. However, the evidence for superior pain relief when Chinese herbal medicine is used on its own, rather than alongside conventional treatment, is more limited.

Is there research behind it?

Yes. The evidence includes placebo-controlled research, multi-centre randomised trials, large meta-analyses and postoperative studies. The field has grown significantly since the 2012 Cochrane review. However, much of the research has methodological limitations including a lack of blinding and geographic concentration in China.

Is the evidence strongest when used alone or alongside conventional care?

Alongside conventional care. The clearest and most consistent benefits in the research appear when Chinese herbal medicine is used as a complementary approach rather than a replacement.

Has this been studied in the UK?

There is UK research, including a feasibility study by Flower et al. (2011) showing that individualised Chinese herbal medicine decoctions can be blinded against placebo in routine practice. However, large definitive UK effectiveness trials have not yet been completed.

References

1. Flower et al. (2012). Chinese herbal medicine for endometriosis. Cochrane Database of Systematic Reviews. DOI: 10.1002/14651858.CD006568.pub3

2. Flower et al. (2011). A Feasibility Study Exploring the Role of Chinese Herbal Medicine in the Treatment of Endometriosis. The Journal of Alternative and Complementary Medicine. DOI: 10.1089/acm.2010.0073

3. Zhao et al. (2020). Chinese Medicine Sequential Therapy Improves Pregnancy Outcomes after Surgery for Endometriosis-Associated Infertility: A Multicenter Double-Blind Placebo Randomized Controlled Trial. Chinese Journal of Integrative Medicine. DOI: 10.1007/s11655-019-3208-2

4. Zhao et al. (2013). Controlling the Recurrence of Pelvic Endometriosis after a Conservative Operation: Comparison between Chinese Herbal Medicine and Western Medicine. Chinese Journal of Integrative Medicine. DOI: 10.1007/s11655-012-1247-z

5. Lin et al. (2023). Chinese Herbal Medicine, Alternative or Complementary, for Endometriosis-Associated Pain: A Meta-Analysis. The American Journal of Chinese Medicine. DOI: 10.1142/s0192415x23500386

6. Zhu et al. (2014). Post-laparoscopic oral contraceptive combined with Chinese herbal mixture in treatment of infertility and pain associated with minimal or mild endometriosis: a randomized controlled trial. BMC Complementary and Alternative Medicine. DOI: 10.1186/1472-6882-14-222

7. Gao et al. (2022). Salvia miltiorrhiza-Containing Chinese Herbal Medicine Combined With GnRH Agonist for Postoperative Treatment of Endometriosis: A Systematic Review and Meta-Analysis. Frontiers in Pharmacology. DOI: 10.3389/fphar.2022.831850

8. Ruan et al. (2021). Efficacy and Safety of SanJieZhenTong Capsules, a Traditional Chinese Patent Medicine, on Long-term Management of Endometriosis: A Randomized Controlled Trial. Reproductive and Developmental Medicine. DOI: 10.4103/2096-2924.313687

9. Zondervan et al. (2020). Endometriosis. New England Journal of Medicine. DOI: 10.1056/NEJMra1810764