How Does Herbal Medicine Work?

Herbal medicine, as practiced in Eastern medical traditions, does not rely on a single active compound to address a narrowly defined pathology. Instead, it works through a multilayered approach that considers three main elements: how the herbs are absorbed and processed in the body, how individual constitution affects treatment (체질), and how complex herbal combinations work synergistically to influence multiple physiological systems at once.

1. Absorption and Pharmacological Pathways

When herbal decoctions , powders, or granules are ingested, the compounds enter the body through the gastrointestinal tract. Most herbs undergo digestion in the stomach and small intestine, where active phytochemicals are absorbed and then circulated via the bloodstream to target organs.

Certain herbs—especially those classified as qi-regulating (理氣) or blood-invigorating (活血)—contain flavonoids, alkaloids, and saponins that have been shown to exert measurable biological effects such as anti-inflammatory, immune-modulating, or vasodilatory actions【1】. These pharmacological effects may align with what Western physiology recognizes as modulation of autonomic nervous activity, endocrine balance, or microcirculation.

2. Constitution (體質) and Pathophysiological Patterns (病機)

Eastern medicine recognizes that the same symptom—say, insomnia or digestive discomfort—can arise from different root causes depending on the patient’s constitutional background. This concept of 體質 (body constitution) reflects inherited and acquired traits such as metabolic rate, organ function, and stress reactivity. Diagnosis, therefore, is not disease-centered but pattern-centered (辨證), where each person’s symptoms are understood as part of a larger systemic imbalance.

For example, fatigue in one patient may be due to qi deficiency (氣虛)—a lack of metabolic vigor—while in another it may arise from dampness stagnation (濕滯) that impairs fluid metabolism. Each would receive a distinct formula, even if their complaints sound similar.

3. Synergistic Mechanisms in Multi-Herb Formulas

Most Eastern herbal prescriptions use complex formulas composed of multiple herbs, typically organized under the Jun-Chen-Zuo-Shi (君臣佐使) principle—commonly translated as monarch, minister, assistant, and envoy. This structure ensures that the main therapeutic goal (e.g., heat-clearing, qi-tonifying) is supported by secondary herbs that enhance efficacy, reduce side effects, or direct the action to specific organs.

A single herb may influence a physiological system, but a well-constructed formula can balance multiple mechanisms: boosting energy while calming inflammation, or clearing toxins while protecting digestion. This approach mimics the body's natural network of interactions rather than targeting isolated receptors.

Recent pharmacological studies support this complexity. For instance, Liu et al. (2015) demonstrated that multi-herb formulas showed greater bioactivity and better immune modulation compared to single-herb extracts in cell-based studies【2】. Meta-analyses have also noted improved outcomes in clinical trials when complex herbal formulas were used, particularly in chronic conditions like irritable bowel syndrome or menopausal symptoms【3】.

Conclusion

Herbal medicine functions through a dynamic, systemic framework. Rather than acting like a synthetic drug designed to block a single receptor, herbal formulas aim to restore balance, modulate bodily functions, and support the body’s ability to heal itself. This multifactorial approach is both a strength and a challenge—it requires careful diagnosis and individualized prescription, but when done correctly, it offers a highly tailored and physiologically integrated form of care.

References

1. Zhang, A., Sun, H., Wang, X., Han, Y., & Wang, P. (2012). Recent advances in metabolomics in the research of traditional Chinese medicine. Journal of Ethnopharmacology, 140(3), 594–603. https://doi.org/10.1016/j.jep.2012.01.042

2. Liu, C. X., Zhang, T. J., & Wang, Y. (2015). Multi-component synergy of herbal medicine in the treatment of metabolic syndrome. Current Drug Metabolism, 16(10), 847–854. https://doi.org/10.2174/1389200216666150817152025

3. Yu, Y., Liu, H., & Zhang, Q. (2020). Efficacy and safety of Chinese herbal medicine for irritable bowel syndrome: A systematic review and meta-analysis. Phytomedicine, 76, 153251. https://doi.org/10.1016/j.phymed.2020.153251