Suan Zao Ren Tang: A Classic Herbal Formula that Benefits Sleep

Chinese herbal medicine (CHM) has a long history of effective use. It is practiced within the framework of Traditional Chinese Medicine (TCM) which has sophisticated internal diagnostic methods independent of biomedicine. This can create cultural barriers preventing access to the proper use of CHM. However, scientific evidence can provide an understanding of biochemical mechanisms and what to expect clinically that help bridge cultural gaps and increase support for the use of CHM in healthcare globally. In an effort to provide insight into CHM, I’ve decided to expand upon a classic herbal formula that benefits sleep.

Introduction

The first recorded mention of herbal formulations based upon TCM theory is found in a 2200-year-old Chinese medical text called the Huangdi Neijing (Inner Canon of the Yellow Emperor) [1]. Formulas are prescribed to address many health concerns and typically consist of 4-18 unique herbs. Combinations of individual herbs that have proven themselves effective over the centuries are known as classic formulas, and these tend to form the basis of modern prescriptions. Classic formulas are tailored to best fit a patient’s presentation by removing or adding herbal ingredients. However, in some instances, classic formulas are good fits in and of themselves.

Sleep is an area of health that many people struggle with. Statistics published in April 2023 show that in the U.S., 50-70 million people have sleep disorders and that women struggle with insomnia 40% more often than men [2]. Insomnia and sleeplessness became especially pronounced during the Covid-19 pandemic; herbal medicine was a great resource in my practice to help provide relief when offering acupuncture was not an option due to mandatory quarantines and social distancing.  

Pharmacological treatments for insomnia such as benzodiazepines, non-benzodiazepine hypnotics and melatonin receptor agonists carry risk of adverse side effects that include daytime sedation, memory impairment, slurred speech, poor judgement, staggering gait, headache, elevated liver enzymes, nightmares, undesired behaviors during sleep, rebound insomnia, tolerance and dependency [3; 4; 5]. Chinese herbal medicine offers safe, clinically effective alternatives.

One of those alternatives is a formula known as Suan Zao Ren Tang (SZRT), translated in English as sour jujube decoction. This formula was first documented in the classic Chinese text Jingui Yaolue (Synopsis of Prescriptions of the Golden Chamber) around 210 A.D. It is widely used in China, Japan, South Korea and other Asian countries. According to classic texts, SZRT brings on a tranquilizing sensation to reduce insomnia, restlessness, palpitations and mental distress [3; 6].

In 2015, the National Health Insurance program in Taiwan found that SZRT was the most prescribed Chinese herbal formula to address insomnia, and it was also the most common formulation in over-the-counter sleeping pills [6].

TCM Indications & Diagnosis

The use of SZRT is indicated when there is a TCM diagnosis of Liver-blood deficiency with deficiency heat. SZRT nourishes blood and clears heat to calm the shen, or spirit, and to relieve irritability. Insomnia, sleeplessness, heart palpitations, night sweating, irritability, dizziness and vertigo are all possible clinical manifestations. A practitioner of Chinese medicine will not only look at symptoms but will also take a thorough health history, tongue and pulse diagnosis to determine the right herbal formula for each individual. 

SZRT is comprised of 5 herbs: suan zao ren, specifically the dried ripe seeds of the Chinese jujube; zhi mu, known as anemarrhenea root; fu ling, also known as the fungus poria; chuan xiong, commonly known as Sichuan lovage root; and gan cao, known as licorice root.

Research

Scientific research has shown that this formula improves sleep quality, prolongs sleep time, increases non-rapid eye movement sleep, protects the functions of the cardiovascular system, and enhances the function of the immune system [6; 7]. Research and clinical practice show that SZRT can take over a week of use before changes are seen with significant improvement after 4 weeks of use [3].

A meta-analysis published in 2018 including 1454 patients showed that SZRT was superior to placebo in the treatment of insomnia, and combinational treatment with diazepam can improve sleep quality significantly over diazepam alone [4]. 13 studies with evidence that was high or moderate were included in analysis.

Biochemical Mechanisms

Components of the main herb, sour jujubes, exert sedative and hypnotic effects by targeting multi-neurotransmitter proteins at pre-synapse and post-synapse interfaces [8].

Research has shown that one component, jujuboside A, affects GABA and serotonin systems through glutamate-mediated excitatory signal pathway [9]. And another component, sanjoinine A, was found to prolong sleeping time through increasing chloride influx and GABA synthesis [4].

While the main herb, sour jujube, enables hypnotic effects through modulation excitement in the nervous system, the four additional herbs concentrate more on the endocrine and immune systems with targeting patterns related to regulation of blood sugar, blood pressure, hormones including estrogen, progesterone and androgens, and immune-related inflammatory pathways [8].

Therefore, looking at this formula as a whole, it can target multiple neurotransmitter receptors at the synapses which are associated with sedative and hypnotic effects, and hit targeting patterns in pathways related to inflammatory regulation and the endocrine system. This means that SZRT can help treat insomnia associated with psychological stress, health conditions of chronic pain, and hormone disorders [8]. This beautifully illustrates the synergistic effect of the 5 individual herbs that make up this classic Chinese herbal formula.

Safety

High-quality randomized controlled trials coupled with a long history of clinical practice have confirmed not only the efficacy, but also the safety of this formula. SZRT is gentle and well-tolerated. Adverse effects reported from the literature were mild and included stomachache, diarrhea, and dizziness [4; 6]. Interestingly, in the meta-analysis mentioned above that synthesized data from 13 studies including 1454 patients, there were more adverse effects reported in control groups compared to the experimental groups taking SZRT [4]. I was unable to find documentation of any serious or life-threatening adverse effects in the literature. It is important to note that research suggests SZRT may potentiate the effects of sedative and hypnotic pharmaceutical drugs.

In conclusion, Chinese herbal medicine can help provide relief of insomnia as well as many other conditions. Herbal formulas should be GMP certified and prescribed by a licensed practitioner of Chinese medicine. Everyone is different and although SZRT may be a great fit for one person it may not be the most appropriate for another, even if symptoms are similar. Additionally, SZRT may need to be modified by replacing or adding other herbs to most accurately fit one’s differential diagnosis according to Chinese Medicine.

Feel free to contact me if you have any questions and if you are interested in scheduling an appointment.

References:

[1] Gu, S. & Pei, S. Innovating Chinese herbal medicine: From traditional health practice to scientific drug discovery. Frontiers in Pharmacology. 2017, vol. 8. P. 381. Available at: doi: 10.3389/fphar.2017.00381.

[2] Suni, E. & Truong, K. Sleep statistics. Sleep Foundation, sleepfoundation.org. April 4, 2023. Available at: https://www.sleepfoundation.org/how-sleep-works/sleep-facts-statistics.

[3] Yeh, C. H. & Arnold, C. K. & Chen, Y. H. & Lai, J. N. Suan zao ren tang as an original treatment for sleep difficulty in climacteric women: A prospective clinical observation. Evidence-Based Complementary and Alternative Medicine. 2011, vol. 2011. P. 673813. Available at: doi: 10.1155/2011/673813.

[4] Zhou, Q. H. & Zhou, X. L. & Xu, M. B. & Jin, T. Y. & Rong, P. Q. & Zheng, G. Q. & Lin, Y. Suanzaoren formulae for insomnia: Updated clinical evidence and possible mechanisms. Frontiers in Pharmacology. 2018, vol. 9. Article 76. Available at: doi: 10.3389/fphar.2018.00076.

[5] Abbott, S. M. & Reid, K. J. & Zee, P. C. Chapter 40 – Circadian disorders of the sleep-wake cycle. Principles and Practice of Sleep Medicine (Sixth Edition), 2017. P. 414-423.e5. Available at: doi: 10.1016/B978-0-323-24288-2.00040-4.

[6] Chan, Y. Y. & Chen, Y. H. & Yang, S. N. & Lo, W. Y. & Lin J. G. Clinical efficacy of traditional Chinese medicine, suan zao ren tang, for sleep disturbance during methadone maintenance: A randomized, double-blind, placebo-controlled trial. Evidence-Based Complementary and Alternative Medicine. 2015, vol. 2015. P. 710895. Available at: doi: 10.1155/2015/710895.

[7] Du, Y. & He, B. & Li, Q. & He, J. & Wang, D. & Bi, K. Simultaneous determination of multiple active components in rat plasma using ultra-fast liquid chromatography with tandem mass spectrometry and application to a comparative pharmacokinetic study after oral administration of suan-zao-ren decoction and suan-zao-ren granule. Journal of Separation Science. 2017, vol 40: 10. Available at: doi: 10.1002/jssc.201601383.  

[8] Gao, J. & Wang, Q. & Huang, Y. & Tang, K. & Yang, X. & Cao, Z. In silico study of anti-insomnia mechanism for suanzaoren prescription. Frontiers in Pharmacology. 2019, vol. 10. P. 925. Available at: doi: 10.3389/fphar.2019.00925.

[9] Cao, J. X. & Zhang, Q. Y. & Cui, S. Y. & Cui, X. Y. & Zhang, J. & Zhang, Y. H. & Bai, Y. J. & Zhao, Y. Y. Hypnotic effect of jujubosides from Semen Ziziphi Spinosae. Journal of Ethnopharmacology. Vol. 130: 1. P. 163-166. Available at: doi: 10.1016/j.anclin.2016.01.007.