Concept of Proof Spirit and its application in modern Homoeopathic Pharmaceutics

Dr Divita Jain(BHMS)

Proof-spirit is defined by act of Parliament as: “being such as shall, at a temperature of 51°F, weighs exactly 12/13th part of an equal measure of purified water”. Modern homoeopathic pharmacies have expanded their repertoire-Extraction Techniques, Biodegradable Options, and Advanced Potentiation Methods: Quality Control and Innovation, Potency variations, Combined Extracts, Mother Tinctures, Globules and Tablets. Proof Spirit is more than just an alcohol in homoeopathy. As modern science and homoeopathy continue to engage in dialogue, proof spirit promises to remain a valuable player in shaping the future of this unique medical system.

Keyword- Homoeopathy, Modern Pharmaceutics, Proof Spirit

Proof-spirit is defined by act of Parliament as: “being such as shall, at a temperature of 51°F, weighs exactly 12/13th part of an equal measure of purified water”. In other words, proof-spirit is a mixture of alcohol and purified water, weighing 12/13th of an equal volume of purified water at 51°F. [1]

Historical Perspective
Proof spirits, a blend of ethanol and water in specific ratios, have played a crucial role in homoeopathic pharmacy since the very beginnings of the practice. Their use dates back to Samuel Hahnemann, the founder of homoeopathy, who employed them as a solvent for the preparation of homoeopathic remedies.

Hahnemann initially used pure alcohol for potentization, but later recognized its strong effects. He observed that diluting alcohol with distilled water created a milder medium while preserving its ability to carry the medicinal imprint of the source substance. This led to the adoption of proof spirits, typically a 90% alcohol solution, as the preferred diluent. In his seminal work, Organon of the Medicine, Hahnemann advocated for the use of alcohol (specifically diluted grain spirits) as a solvent due to its purity, miscibility with various substances, and ability to preserve remedies. [2]


Proof spirit contains: 49.28% ethanol by weight (about 57% by volume). Degrees of proof express the percentage of proof spirit present, so 70° proof spirit contains 0.7 × 57% alcohol.[3]

Specific Gravity: 0.91976 at 15.6°C or 60°F. [4]


Spirit of this strength is called 100% Proof spirit. It contains 57.1% by volume or 49.28% by weight of ethyl alcohol and 42.9% by volume of water. This concentration was originally fixed as being the most dilute aqueous alcohol, which when passed on to gunpowder and lit, would fire the powder; if the spirit contained more water, the gunpowder was too wet to fire.

According to British Homoeopathic Pharmacopoeia, Proof Spirit is made by mixing 5 measures of  rectified spirit with 3.2 measures of distilled water. The mixture should then be agitated and allowed to cool to 60°F and a sufficient quantity of distilled water added to increase the bulk to 8 measures.


Expression of  Proof Spirit:

  1. Under proof (U.P.)
  2. Over proof (O.P.)
  • Under proof (U.P.)

Alcohol weaker in strength than proof spirit is known as under proof. For example:

60 U.P.: Means that 100 parts of this alcohol contains 40 parts (by volume) of proof spirit ‘40’ is arrived at by subtracting from 100 the respective U.P. strength i.e. 100-60=40, of the said alcohol.

  • Over Proof (O.P.)

Alcohol stronger in strength than proof spirit is called over proof. For example:

60 O.P.: Means that in 100 parts of this alcohol if 60 parts of purified water is added, then 60 parts of proof will be obtained (all by volume). [4]

Industrial Importance

Beyond their role in individual patient care, proof spirits hold significant industrial importance within the homoeopathic pharmacy sector. Let’s delve into the key aspects of this impactful relationship:

  1. Solvent and Base for Homoeopathic Preparations: Proof spirits act as the primary solvent for a vast majority of homoeopathic mother tinctures. These tinctures, prepared by extracting active ingredients from plants, minerals, and animal sources, form the foundation for further dilutions and potencies. The high alcohol content of proof spirits facilitates efficient extraction of these active ingredients, ensuring their optimal potency and therapeutic efficacy.
  2. Standardization and Consistency: The use of proof spirits as a standardized solvent promotes consistency in homoeopathic preparations across different manufacturers and batches. This consistency is crucial for maintaining the quality and reliability of homoeopathic medicines, which are often used in minute doses. Regulatory bodies like the European Pharmacopeia and the Homoeopathic Pharmacopoeia of the United States define strict specifications for acceptable proof spirits used in homoeopathic preparations. These specifications ensure the purity, ethanol content, and absence of harmful contaminants.
  3. Economic Impact on the Industry: The extensive use of proof spirits in homoeopathic preparations creates a significant demand for this product within the pharmaceutical industry. This demand translates to economic benefits for manufacturers and distributors of proof spirits, contributing to the overall growth and stability of the homoeopathic sector. The global homoeopathic market is projected to reach USD 10.5 billion by 2025, with a significant portion of this growth attributed to the increasing demand for standardized and high-quality homoeopathic medicines, which rely heavily on proof spirits for their preparation.
  4. Research and Development: Proof spirits play a crucial role in research and development activities within the homoeopathic field. Researchers utilize them to prepare new mother tinctures, test the efficacy of different potencies, and develop novel homoeopathic formulations. The consistent and reliable nature of proof spirits allows researchers to conduct controlled experiments and obtain accurate data, thereby contributing to the advancement of homoeopathic knowledge and practice.
  5. Environmental Considerations: The production and use of proof spirits, typically derived from ethanol, raise concerns about environmental sustainability. However, the homoeopathic industry is increasingly adopting sustainable practices, such as using bioethanol derived from renewable sources. Research is also ongoing to explore alternative solvents for homoeopathic preparations, with the aim of minimizing the environmental footprint of the industry. [5], [6]

Proof Spirit’s Virtues

  • Excellent solvent – Proof spirit effectively dissolves a wide range of plant and mineral substances, extracting their active constituents while leaving behind unwanted materials.
  • Preservative – The alcohol content inhibits the growth of bacteria and fungi, contributing to the long shelf life of homoeopathic remedies.
  • Potentization medium – Proof spirit plays a crucial role in the serial dilution and succession process, a core principle in homoeopathic practice.
  • Penetration Enhancer – Proof spirit facilitates the absorption of active ingredients through cell membranes, allowing for deeper and more efficient action within the body. [7]

Modern Applications

While traditional approaches relied heavily on proof spirit, modern homoeopathic pharmacies have expanded their repertoire.

  • Green and Sustainable Practices:

Extraction Techniques: Proof spirits can be used in green extraction techniques like supercritical fluid extraction for certain plant-based remedies. This reduces reliance on harmful solvents and minimizes environmental impact.

Biodegradable Options: Research is exploring the use of biodegradable alcohol alternatives in homoeopathic preparations. While proof spirits remain the current standard, these eco-friendly options hold promise for a more sustainable future.

  • Advanced Potentiation Methods:

Sonication: Proof spirits can be used in conjunction with sonication, a sound-based technique, to enhance the potentiation of certain remedies. This potentially increases the efficacy and reduces the number of dilutions needed.

Nanoparticle Technology: Some research explores the use of proof spirits for preparing nanoparticle-based homoeopathic medicines. This could lead to targeted delivery and potentially improved therapeutic effects.

  • Quality Control and Innovation:

Fingerprinting Techniques: Proof spirits can be analyzed using advanced spectroscopic techniques to ensure the quality and consistency of homoeopathic preparations. This contributes to robust quality control standards.

  • Potency variations – Different proof spirit concentrations can be used to prepare remedies of varying potencies, catering to diverse therapeutic needs.
  • Combined Extracts – Proof spirit can be used to create complex remedies, combining extracts from multiple plants or substances for synergistic effects.
  • Liquid and Non-liquid forms – Proof spirit facilitates the preparation of both liquid and non-liquid remedies, such as trituration and creams.
  • Mother Tinctures – As the base for preparing mother tinctures the concentrated extracts of plant and mineral substances.
  • Globules and Tablets – Proof spirit is used to bind and shape sugar globules and compressed tablets, the common dosage forms of homoeopathic medicines.
  • Research and development – Proof spirit continues to be used in research and development of new homoeopathic medicines allowing for controlled extraction and analysis of active ingredients. [8]

As homoeopathy evolves, the use of proof spirit continues to be assessed and refined. Research explores its potential in optimizing extraction processes, enhancing the stability of certain remedies and even developing new delivery systems.

Proof Spirit is more than just an alcohol in homoeopathy; it’s a time-tested tool that has enabled the creation and preservation of potent remedies for generations. As modern science and homoeopathy continue to engage in dialogue, proof spirit promises to remain a valuable player in shaping the future of this unique medical system.

Author wants to acknowledge Dr Rajesh K. Meena, Associate Professor & HoD, Homoeopathic Pharmacy, and Dr Astha Mathur, Assistance professor, Homoeopathic pharmacy, for guidance and support.


  1. Mandal P.P, Mandal B. A Textbook of Homoeopathic Pharmacy. Kolkata; NCBA LTD.: 2023
  2. Hahnemann Samuel. Organon of the Medicine. 6th New Delhi; B Jain Publishers Pvt Ltd: 2013.
  3. Oxford Reference. Retrieved 22 Dec. 2023, from
  4. Banerjee D.D. Augmented Textbook of Homoeopathic Pharmacy. New Delhi; B.Jain publishers (P) LTD.:2023
  5. Global Homoeopathic Market Size, Share & Trends Analysis Report By 2025. [Internet] 2023 Dec 26. (cited on 2023 Dec 26) Available from:
  6. Arshad Muhammad, Abbas Mazhar, Javed Sadia, Adilm Muhammad, Shahzad Mirza Imran, Iqbal Munawar. (2020). Sustainable Ethanol Production: An Overview. [Internet] 2020. DOI 10.1007/978-3-030-59280-6_1.
  7. Goel S. Art and Science of Homoeopathic Pharmacy. New Delhi; IBPP LTD: 2022.
  8. Holandino Carla, Gold Peter, Ancken Adalberto von, Bonamin Leoni V. Int J High Dilution Res.2023;22 (2):01-20.

Dr Divita Jain, (BHMS)
University College of Homoeopathy,
(Constituent College of Dr Sarvepalli Radhakrishnan Rajasthan Ayurved University, Jodhpur),
Old CHC Building, Ajmeri Gate, Kekri – 305404.

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