Neidan, inner alchemy: an introduction for practitioners

Author: Raymond Hackland · Last reviewed: 18 October 2026 · Reading time: about 11 minutes

In short

• What this is: Neidan (内丹, nèidān, “inner elixir”) is the Daoist tradition of inner alchemy. It borrowed the language of laboratory alchemy and turned it into a path of self-cultivation. This article traces it from its debated beginnings through the Cantong qi, the Zhong-Lü texts, Zhang Boduan’s Wuzhen pian and the Quanzhen order to the Ming and Qing periods. It is the sixth article of our neigong series.
• What the evidence says: The history is well documented in surviving texts, although many dates and attributions are debated. Neidan’s goals are religious. Popular claims that it grants immortality, that a “golden elixir” is a remedy for illness, or that it is the same as kundalini go beyond what the texts or research show.
• What it means for your practice: Much of the vocabulary of modern Qigong and neigong comes from neidan. Knowing where it comes from helps you see that the classical masters themselves set neidan apart from ordinary breathing methods.

What tradition says

Label for this section: Tradition only (documented history).

Two alchemies: waidan and neidan. Chinese alchemy has two branches [1]. External alchemy, waidan (外丹, wàidān), compounded elixirs by heating minerals and metals such as cinnabar and lead in a crucible; a modern dictionary defines it as the preparation of “so-called elixirs of deathlessness” [3]. Internal alchemy, neidan, borrows much of that vocabulary and imagery but aims to produce the elixir within the practitioner’s own person [1]. The same dictionary defines it as using “one’s own body as the furnace”, with essence and qi as the ingredients, which spirit moves and forms into the elixir [3]. The Tang dynasty (7th–9th centuries) was the “golden age” of external alchemy [1]. It was also the time when elixir poisoning killed at least two and possibly four Tang emperors [1]. Older studies explained the shift to inner alchemy by these poisonings; Pregadio argues that the transition was much more complex [1].

When does the word neidan first appear?

Label for this section: Tradition only (documented history; dates debated).

The question is, in the words of the scholar Farzeen Baldrian-Hussein, “a thorny one”, because the sources “are of dubious date” [4]. Three candidates are usually named.

• The Buddhist master Huisi (慧思, 515–577) [5, 13]. His vow text, as printed in the Buddhist canon, contains the line “by the power of the outer elixir, I will cultivate the inner elixir” (藉外丹力修內丹) [5]. Arthur Waley and Joseph Needham took this as the first use of the terms [4]. Baldrian-Hussein reports that Huisi’s biographer Paul Magnin accepts the vow itself, made in 559, but doubts its Daoist passages, and concludes that “there is no certainty” that the phrases with neidan and waidan “are not a later interpolation” [4].
• Su Yuanlang (苏元朗, also written Su Yuanming, 苏元明; perhaps late 6th century). The scholar Chen Guofu believed the term was first used in the Zhidao pian (旨道篇) attributed to him; Baldrian-Hussein calls this source dubious too [4].
• Deng Yuzhi (邓郁之), a hermit of Mount Heng, whose later biographies use the terms, although an older version of his biography does not [4].

Pregadio sums up: accounts of Su Yuanlang, Deng Yuzhi and Huisi “are found in sources significantly later than the events they purport to record and are not historically reliable”; the earliest traces of neidan in the extant literature are in the works of Tao Zhi, in the second half of the 8th century [1]. Baldrian-Hussein concludes that the term came into use between the Tang and Song dynasties [4].

The Cantong qi: a foundational text with a debated date

Label for this section: Tradition only (documented history; dates debated).

The Zhouyi cantong qi (周易參同契, Seal of the Unity of the Three) is traditionally attributed to Wei Boyang (魏伯阳) of the 2nd century CE. Pregadio notes that this attribution only became current at the end of the first millennium, and in the encyclopedia article he dates the text to between the mid-5th and mid-7th centuries [1, 2]. It opens with the trigrams of the Book of Changes: “Qian and Kun are the gate of change, the father and mother of all the hexagrams” (乾坤者，易之門戶，眾卦之父母) [6]. Neidan lineages read it as the first neidan text. Pregadio points out that no source suggests neidan existed before the 8th century, and calls it “not the first Neidan text, but the first text of Neidan”: its alchemical passages describe waidan methods, but its symbolic language also lets them be read with reference to neidan [1]. One passage, in the 35-chapter arrangement of the Yuan-dynasty commentator Chen Zhixu (陈致虚), is about stillness: “Ears, eyes and mouth are the three treasures; shut them and let nothing flow out” (耳目口三寶，閉門無發通) [6]. These are the “three treasures” of the senses, a different triad again from jing, qi and shen.

Zhong-Lü: the first clear tradition

Label for this section: Tradition only (documented history).

The first clearly identifiable neidan tradition took shape in the 9th and 10th centuries and is named after two immortals, Zhongli Quan and Lü Dongbin [1, 2]. Its main text, the Zhong-Lü chuandao ji (鍾呂傳道集), is a dialogue. Lü opens by asking: “What way can make a person live at ease without illness, grow strong without ageing, live without dying?” (人之生也，安而不病、壯而不老、生而不死，何道可致如此？) [7]. The text then explains its cosmology and practices at length. It also has a chapter on the “ten demons and nine difficulties” (十魔、九難) that block the practitioner: visions of wealth, rank, pleasure or grief that arise in practice, each with the same advice, “if you see it, do not take it as real” (如見，不得認) [7].

Zhang Boduan and the Wuzhen pian

Label for this section: Tradition only (documented history).

After the Cantong qi, the main neidan text is the Wuzhen pian (悟真篇, Awakening to Reality), a work in verse by Zhang Boduan (张伯端, 987?–1082) [1]. His preface tells how, in the jiyou year of the Xining era (1069), he went to Chengdu and met a “realised person” who passed on to him the instructions on the golden elixir. He set down what he had learned in “eighty-one poems” (九九八十一首) and signed the preface “on New Year’s Day of the yimao year of Xining”, that is, 1075 (熙寧乙卯歲旦) [8].

The preface is worth reading for anyone who practises breathing methods. Zhang lists methods that are “easy to meet but hard to complete” (易遇而難成): among them “breathing in the clear and breathing out the turbid” (納清吐濁), massage, visualisation, chanting, and “keeping the spirit in place and holding the breath” (存神閉息). True alchemy, he says, is “hard to meet but easy to complete” [8]. He also criticises readers who take the alchemical terms literally, as when they “take heart and kidneys for Kan and Li, liver and lungs for dragon and tiger” [8]. And he saw the three teachings as one: “the teachings are divided into three, but the Way returns to one” (教雖分三，道乃歸一) [8].

Southern and Northern lineages

Label for this section: Tradition only (documented history).

In the 13th century Zhang Boduan was placed at the head of the Southern Lineage (Nanzong, 南宗); the lineage was probably formalised later, perhaps by Bai Yuchan, and Zhang’s first named successor was not his direct disciple [1]. The classical three-stage practice of refining essence, qi and spirit was devised on the basis of the Wuzhen pian and Southern Lineage teachings [1]. The Northern Lineage (Beizong, 北宗) is the original core of the Quanzhen order [1]. Under the Yuan dynasty several authors tried to merge the two; one was Li Daochun, who warned against reading the “three passes” as fixed points on the spine (尾閭、夾脊、玉枕), which he called “only technique, not the essential” [1, 11].

Quanzhen: Wang Chongyang and Qiu Chuji

Label for this section: Tradition only (documented history).

Quanzhen (全真, “Complete Reality” or “Complete Perfection”) was founded in the north by Wang Zhe, known as Wang Chongyang (王重阳, 1113–70), and his seven main disciples [1, 2]. Today it is a celibate monastic order and, with the Celestial Masters, one of the two main branches of Daoism; its practices include meditation and inner alchemy [2]. The status of neidan in early Quanzhen is “not entirely clear”, and neidan texts attributed to Wang Chongyang and Qiu Chuji are not reliable [1].

Wang Chongyang’s Fifteen Discourses (重陽立教十五論) put the mind first. “Sitting”, he writes, does not mean keeping the body upright with eyes closed; “true sitting” means that at all hours, walking, standing, sitting or lying, “the mind is like Mount Tai, unmoved and unshaken” (心如泰山，不動不搖) [9]. In his first discourse he warns against both overexertion and inactivity: “movement and stillness must find their middle” (動靜得其中) [9].

Qiu Chuji (丘处机, 1148–1227) travelled west at the summons of Chinggis Khan. In his disciple Li Zhichang’s account, the Khan asked at their first meeting, in the spring of 1222, what “medicine of long life” he had brought. Qiu replied: “There is a way of guarding life, but there is no medicine of long life” (有衞生之道，而無長生之藥) [10, 14]. The Longmen (Dragon Gate) lineage later claimed descent from Qiu Chuji [1, 2].

Ming and Qing, briefly

Label for this section: Tradition only (documented history).

In the Ming and Qing periods many neidan masters claimed affiliation with the Longmen lineage, which under the Qing became the orthodox Quanzhen lineage [1, 2]. Wu Shouyang (1574–1644) and Liu Huayang (1735–99) are seen as founders of the Wu-Liu branch, which combined Buddhist meditation with Daoist methods [1]. The Secret of the Golden Flower (金華宗旨, Jinhua zongzhi), from about 1700, became known for its practice of “reversing the light”, and Liu Yiming (1734–1821) wrote one of the most complete expositions of neidan doctrine [1]. Today a Chinese dictionary even files neidan under “qigong studies” (今屬氣功學) [3]. Our series introduction, “What is neigong? An introduction“, describes how the word neigong came to cover this.

What science says

Label for this section: Early evidence (case reports and a review); historical part Tradition only.

Neidan’s own texts warn about practice going wrong, as the Zhong-Lü chapter on “demons” shows [7]. The phrase zǒuhuǒ rùmó (走火入魔), “fire going astray and entering the demonic”, originally described, in Daoist usage, a state in which a practitioner refining essence, qi and spirit pushes ahead too hastily, so that the inner qi “rushes about” in a manic state, and the illusions that follow [3]. In modern China psychiatrists described “qigong deviation” and “qigong-induced mental disorders”. A 1999 review found that Qigong practised inappropriately may induce abnormal psychosomatic responses and even mental disorders, but that a causal link is difficult to establish, and suggested that many cases are better called “qigong-precipitated”, with practice acting as a stressor in vulnerable people [12]. The review also noted a conspicuous lack of controlled data, so this literature is not a measure of risk [12]. If you have a mental health condition, read who should be careful with breathing practices before starting any practice.

Where popular claims go beyond the evidence

Label for this section: Speculative.

• “Neidan makes you immortal.” The texts do use the language of immortality, and in the main Zhong-Lü dialogue “living without dying” is part of the opening question [7]. Pregadio notes that immortality in alchemy is usually meant as a spiritual condition [1]. Wang Chongyang called people who want “never to die and leave the ordinary world” “greatly foolish, not understanding the principle” (欲永不死而離凡世者，大愚不達道理也) [9], and Qiu Chuji told the Khan there is no medicine of long life [10].
• “The golden elixir is a remedy for disease.” The texts do list healing among the benefits of alchemy [1], but in neidan the elixir is not a substance you take, and the external elixirs that people did take poisoned emperors [1]. No research shows that neidan works as a remedy for any illness.
• “Neidan is Chinese kundalini yoga.” Kundalini is a Sanskrit term from Indian traditions. None of the Chinese sources we quote use the idea, and equating the two flattens both.
• “Follow these steps and you will open the microcosmic orbit.” Neidan texts call the timing of practice, the “fire phases”, one of the most secret parts of the work, and say that masters adapted it to each student [1]. A book or video cannot promise an outcome, and neither do we.

How this relates to the Six Healing Sounds, Qigong and neigong

Label for this section: Tradition only (documented history); Raymond’s own approach is marked as his, and its link to the science of vibration is labelled Speculative.

The Six Healing Sounds first appear in the Yangxing yanming lu, an anthology traditionally attributed to Tao Hongjing (died 536) and first recorded between the 6th and 8th centuries, in a chapter on breathing practices, as six ways of breathing out; see the history of Liu Zi Jue. Baldrian-Hussein found that alchemical texts often define neidan as a breathing technique, such as embryonic breathing (taixi) or circulating qi (xingqi), which our article “Breath in the classics: tuna, fuqi, lianqi and embryonic breathing” describes [4]. Yet Zhang Boduan, a master of the tradition, placed breathing methods among those that are “easy to meet but hard to complete” [8]. The Yuan-dynasty author Li Daochun, mentioned above, was more explicit: in his Zhonghe ji he listed the “six-character qi” (六字氣), that is, the six sounds, together with the Baduanjin (八段锦), holding the breath to move the qi, and many other techniques, among the “small methods” (小法) which, however diligently they are practised, “in the end cannot accomplish the great work” (終不能成其大事) [11]; this is one Yuan author’s ranking, measured against the religious goal of inner alchemy. So the honest summary is that breath practice and inner alchemy overlap in their vocabulary, and sometimes in practice, but they are not the same thing. Our articles “The three dantians: what the classical texts say” and “Jing, qi and shen: the three treasures of inner alchemy” explain the terms neidan uses.

How Raymond’s practice relates to this. Raymond’s practice is breath-led: you breathe in quietly through the nose and breathe the six sounds out through the mouth, “voiced through the breath”, not sung, working over time towards a silent exhalation. The breathing stays slow and controlled throughout, with no breath holds and no fast breathing. His practice does not teach neidan or its refining stages (refining essence into qi, and so on), and makes no claim to work on essence or spirit.

Label for the next paragraph: Speculative, based on Raymond’s own description. Raymond links the sounds to the science of sound and vibration: in theory, the voiced breath may reach the organs and set them vibrating. This has not been shown, and he does not claim that it works; what can be felt is the vibration of your own voice, as What is resonance? explains, and we know of no measurements of a particular sound vibrating a particular organ (see our article on vowels and formants). He also uses a visualisation in the spirit of neigong: you imagine yourself as the resonance, travelling with each sound to its organ, and with xi through the whole body (the triple burner). This rests on his own experience and that of his participants, not on a scientific finding; he describes his work as bridging the gap between the science and the experience. None of this is a health claim, and none of it is the refining of essence, qi and spirit described above.

Resonance Heritage Qi is a personal, music-assisted practice inspired by Liu Zi Jue: connected to it, not a replacement for the traditional form or for study with a teacher of that tradition.

Where this series goes next

Next in our neigong series: “Internal and external: neijia, waijia and the epitaph of 1669”, on the internal martial arts, followed by “Stillness and posture: sitting and standing practice in the internal traditions”.

Sources

1. Pregadio F, 2019. The Way of the Golden Elixir: An Introduction to Taoist Alchemy. 3rd edition. Mountain View: Golden Elixir Press (sections 1, 5, 6, 7 and 10). https://goldenelixir.com/files/The_Way_of_the_Golden_Elixir.pdf
2. Pregadio F. Religious Daoism. Stanford Encyclopedia of Philosophy, first published 19 August 2016, substantive revision 31 August 2020 (sections 3.7, 10.2 and 10.3). https://plato.stanford.edu/entries/daoism-religion/
3. Ministry of Education (Taiwan). 重編國語辭典修訂本 (Revised Mandarin Chinese Dictionary), entries 外丹, 內丹 and 走火入魔, read via the open edition at moedict.tw, accessed 18 October 2026. https://www.moedict.tw/
4. Baldrian-Hussein F, 1989. Inner alchemy: notes on the origin and use of the term neidan. Cahiers d’Extrême-Asie 5:163–190 (pp. 164–171 and abstract). https://doi.org/10.3406/asie.1989.947
5. 慧思 Huisi. 南嶽思大禪師立誓願文 Nanyue Si dachanshi lishi yuanwen. Taishō canon T46, no. 1933, pp. 787a (birth) and 791c (the neidan line). CBETA XML edition, accessed 18 October 2026, https://github.com/cbeta-org/xml-p5/blob/master/T/T46/T46n1933.xml ; Wikisource edition: https://zh.wikisource.org/wiki/南嶽思大禪師立誓願文
6. 周易參同契 Zhouyi cantong qi, chapters 1 (大易總敘章) and 22 (關鍵三寶章) in the 35-chapter arrangement of Chen Zhixu 陳致虛 (Yuan dynasty), from his 周易參同契分章注 Zhouyi cantong qi fenzhang zhu. Chinese text, Wikisource editions (the arranged text, and Chen Zhixu’s commentary in the Siku quanshu), accessed 18 October 2026. https://zh.wikisource.org/wiki/周易參同契 and https://zh.wikisource.org/wiki/周易參同契分章注_(四庫全書本)
7. 鍾呂傳道集 Zhong-Lü chuandao ji, sections 論真仙第一 and 論魔難第十七. Chinese text, Wikisource edition, accessed 18 October 2026. https://zh.wikisource.org/wiki/鍾呂傳道集
8. Zhang Boduan 張伯端. 悟真篇 Wuzhen pian, preface (悟真篇序). Chinese text, Wikisource edition (Zhengtong Daozang), accessed 18 October 2026. https://zh.wikisource.org/wiki/悟真篇
9. Wang Zhe 王喆 (Wang Chongyang). 重陽立教十五論 Chongyang lijiao shiwu lun, discourses 1, 7 and 15. Chinese text, Wikisource edition (Zhengtong Daozang), accessed 18 October 2026. https://zh.wikisource.org/wiki/重陽立教十五論
10. Li Zhichang 李志常. 長春真人西遊記 Changchun zhenren xiyou ji, juan 1. Chinese text, Wikisource edition, accessed 18 October 2026. https://zh.wikisource.org/wiki/長春真人西遊記/卷上
11. Li Daochun 李道純. 中和集 Zhonghe ji, juan 3. Chinese text, Wikisource edition (Zhengtong Daozang), accessed 18 October 2026. https://zh.wikisource.org/wiki/中和集 ; checked against the Kanripo edition of the Zhengtong Daozang (DZ 249, KR5a0250), https://github.com/kanripo/KR5a0250
12. Ng BY, 1999. Qigong-induced mental disorders: a review. Australian and New Zealand Journal of Psychiatry 33(2):197–206. https://doi.org/10.1046/j.1440-1614.1999.00536.x
13. Daoxuan 道宣. 續高僧傳 Xu gaoseng zhuan, juan 17, biography of Huisi (釋慧思). Taishō canon T50, no. 2060, p. 563c. CBETA XML edition, accessed 18 October 2026. https://github.com/cbeta-org/xml-p5/blob/master/T/T50/T50n2060.xml
14. Waley A (trans.), 1931. The Travels of an Alchemist: The Journey of the Taoist Ch’ang-ch’un from China to the Hindukush at the Summons of Chingiz Khan, Recorded by His Disciple Li Chih-ch’ang. London: George Routledge & Sons (pp. 99–101, the dating note on p. 99). Scan at the Internet Archive, accessed 18 October 2026. https://archive.org/details/dli.ministry.24091

Source quality note: [5] to [11] and [13] are primary Chinese texts, read in digital editions (Wikisource and, for [5] and [13], the CBETA edition of the Taishō canon); the translations are our own working translations. [6] follows the arrangement of the Yuan commentator Chen Zhixu; other editions divide the text differently. [14] is a scholarly translation of [10]. Huisi’s dates follow his own vow (birth) and his 7th-century biography (death); Pregadio gives 517–77. For dates, attributions and the lineage history we rely mainly on the scholar Fabrizio Pregadio [1, 2] and on Baldrian-Hussein’s study of the term neidan [4]; we did not consult Robinet, Kohn or Komjathy for this article. The dates of the Cantong qi, of the earliest uses of neidan and of the early Southern Lineage are debated, as noted in the text. [3] is an official dictionary and gives modern definitions. [12] is a review of case literature; we could read only its published abstract.