Er Xian Tang (二仙汤) — Two Immortals Decoction

Er Xian Tang is the principal modern Chinese herbal formula for perimenopausal and menopausal symptoms driven by combined Kidney Yin and Yang deficiency with rising Empty Fire — hot flushes^[3] alternating with cold lower back, night sweats with fatigue^[9], irritability with weakness. Developed in the 1950s at the Shanghai College of TCM, the formula combines two powerful Yang-tonifying “immortals” (Xian Mao and Yin Yang Huo) with Ba Ji Tian, Dang Gui, Huang Bai and Zhi Mu to address the mixed hot-cold deficiency pattern unique to the menopausal transition.

On this page

1. Overview
2. TCM pattern
3. Key herbs
4. Formula actions
5. Conditions treated
6. Cautions
7. Frequently asked questions

Overview

Er Xian Tang — Two Immortals Decoction — was developed in the 1950s at the Shanghai College of Traditional Chinese Medicine specifically for menopausal syndrome. Its name refers to its two principal herbs, Xian Mao (Curculigo) and Yin Yang Huo (Epimedium), both of which powerfully tonify Kidney Yang. The formula addresses the complex mixed pattern of Kidney Yin and Yang deficiency with rising Empty Fire that is characteristic of the menopausal transition.

TCM pattern

Er Xian Tang is prescribed for Kidney Yin and Yang deficiency with Empty Fire rising, producing an apparently contradictory combination of hot and cold signs: hot flushes alternating with cold sensations in the lower back and limbs, night sweats alongside fatigue, irritability alongside weakness. This mixed pattern is extremely common in perimenopausal and menopausal women.

Key herbs

1. Xian Mao (Curculigo orchioides rhizome, 6-15g) — powerfully warms Kidney Yang; one of the two “immortals”
2. Yin Yang Huo (Epimedium grandiflorum herb, 9-15g) — tonifies Kidney Yang and strengthens the sinews; the second “immortal”
3. Ba Ji Tian (Morinda officinalis root, 6-9g) — tonifies Kidney Yang and strengthens the lower back and knees
4. Dang Gui (Angelica sinensis root, 6-12g) — nourishes Blood and Liver Yin; balances the warming Yang herbs
5. Huang Bai (Phellodendron amurense bark, 4-9g) — clears Empty Fire from the Kidney without damaging Yang
6. Zhi Mu (Anemarrhena asphodeloides rhizome, 4-9g) — nourishes Yin and clears Empty Fire; works synergistically with Huang Bai

Formula actions

1. Tonifies Kidney Yang and Essence
2. Nourishes Kidney Yin
3. Drains Empty Fire
4. Regulates the Chong and Ren channels

Conditions treated

1. Menopausal and perimenopausal symptoms — commonly used in TCM practice for the mixed hot-cold pattern of hot flushes with fatigue and cold lower back
2. Hypertension in menopausal women where Kidney Yin and Yang deficiency underlies the pattern
3. Premature ovarian insufficiency and elevated FSH levels
4. Insomnia[8], night sweats and hot flushes in perimenopausal women

Cautions

Always consult a qualified Chinese herbalist registered with the Register of Chinese Herbal Medicine (RCHM). Online herbal consultations are available. See the prices page for costs.

Prefer to be treated from home? Chinese herbal medicine online consultations are available throughout the UK and worldwide. After a full video consultation, Dr (TCM) Attilio D'Alberto formulates a bespoke herbal prescription and posts your Chinese herbs directly to your door.

Frequently asked questions about Er Xian Tang

What is Er Xian Tang used for?

Er Xian Tang is used primarily for menopausal and perimenopausal symptoms — particularly the mixed hot-cold pattern of hot flushes with fatigue and cold lower back. It is also used for hypertension^[19] in menopausal women where Kidney Yin and Yang deficiency underlies the pattern, premature ovarian insufficiency, elevated FSH, and insomnia with night sweats in perimenopausal women.

How does Er Xian Tang work?

The two “immortals” Xian Mao and Yin Yang Huo strongly tonify Kidney Yang and Essence, while Ba Ji Tian reinforces the Yang tonification. Dang Gui nourishes Blood and Liver Yin to balance the warming herbs. Huang Bai and Zhi Mu cool the Empty Fire that rises when Yin is depleted — the heat-clearing pair without further damaging the underlying Yang. The result is simultaneous tonification of both Yin and Yang with Fire-clearing, which is the exact requirement of perimenopausal hormonal imbalance.

How long does Er Xian Tang take to work for hot flushes?

Most patients notice a reduction in hot-flush frequency and intensity within 4–6 weeks of daily granule treatment. Full benefit typically appears at 8–12 weeks. The formula is often continued for 3–6 months across the perimenopausal transition, with periodic review and individualisation.

Can Er Xian Tang be taken with HRT?

Yes — the formula combines safely with HRT and can be a useful adjunct where HRT alone has not fully controlled hot flushes, mood symptoms or fatigue. It also remains useful for women who cannot take HRT (e.g., due to a history of breast cancer) or who prefer not to. Always tell your doctor and gynaecologist what herbs you are taking.

Are there side effects of Er Xian Tang?

Generally well tolerated. Possible issues include mild loose stools (from Dang Gui) and, rarely, increased heat sensation if the Yang-tonifying herbs are mismatched to the patient’s actual constitution. Should not be used in patients with a strongly Yang-excess presentation (red face, severe insomnia, high blood pressure from Liver Fire alone). Should always be prescribed by a qualified RCHM herbalist following a full TCM assessment.

References

[3] Li M, Hung A, Lenon GB, Yang AWH. Chinese herbal formulae for the treatment of menopausal hot flushes: A systematic review and meta-analysis. PLoS One. 2019 Sep 19;14(9):e0222383. https://doi.org/10.1371/journal.pone.0222383. PMID: 31536531.

[8] Hu J, Teng J, Wang W, Yang N, Tian H, Zhang W, Peng X, Zhang J. Clinical efficacy and safety of traditional Chinese medicine Xiao Yao San in insomnia combined with anxiety. Medicine (Baltimore). 2021 Oct 29;100(43):e27608. https://doi.org/10.1097/MD.0000000000027608. PMID: 34713840.

[9] Wang YY, Li XX, Liu JP, Luo H, Ma LX, Alraek T. Traditional Chinese medicine for chronic fatigue syndrome: a systematic review of randomized clinical trials. Complement Ther Med. 2014 Aug;22(4):826-33. https://doi.org/10.1016/j.ctim.2014.06.004. PMID: 25146086.

[19] Wang J, Xiong X, Liu W. Tianma Gouteng Yin as Adjunctive Treatment for Essential Hypertension: A Systematic Review of Randomized Controlled Trials. Evid Based Complement Alternat Med. 2013;2013:706125. https://doi.org/10.1155/2013/706125. PMID: 23710230.