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 Table of Contents  
Year : 2016  |  Volume : 10  |  Issue : 4  |  Page : 249-257

Formic acid : A multicentric observational homoeopathic clinical verification trial

1 Central Council for Research in Homoeopathy, New Delhi, India
2 Dr. Anjali Chatterjee Regional Research Institute (Homoeopathy), Kolkata, West Bengal, India
3 Dr. D. P. Rastogi Central Research Institute (Homoeopathy), Noida, India
4 Homoeopathic Drug Research Institute, Lucknow, Uttar Pradesh, India
5 Regional Research Institute for Homoeopathy, Puri, Odisha, India
6 Regional Research Institute for Homoeopathy, Shimla, Himachal Pradesh, India
7 Retired, Dr. Anjali Chatterjee Regional Research Institute (Homoeopathy), Kolkata, West Bengal, India
8 Clinical Research Unit (Homoeopathy), Port Blair, Andaman and Nicobar Islands, India
9 President, Homoeopathy University, Jaipur, Rajasthan, India

Date of Web Publication17-Nov-2016

Correspondence Address:
Jaya Gupta
Central Council for Research in Homoeopathy, New Delhi
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0974-7168.194320

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Aims: This study was done to clinically verify the symptomatology of Formic acid by ascertaining the symptoms improved during verification and to incorporate new findings (if any) to the known symptomatology of Formic acid. Methods: A multicentric observational clinical verification study was conducted at nine research centers of Central Council for Research in Homoeopathy to verify the proving symptoms of rarely used medicine, Formic acid. Two hundred and seventy participants having symptomatological similarity with Formic acid were included and prescribed in 6C, 30C, 200C, and 1M potencies, as per need of each case. The data were compiled in a specially designed Excel spreadsheet for further analysis. The collected data were presented in terms of descriptive statistics. Prevalence of the symptoms in the responding and nonresponding population was compared using Chi-square or Fisher's exact test. Results: Out of 266 followed up patients, 215 cases responded (80.8%) with 95% confidence interval of 0.75-0.85. The number of symptoms verified was as follows: proving symptoms (n = 11) and new observations (n = 22). The widely emerged new general symptoms, i.e., clean tongue, disturbed sleep, loose stool, tastelessness, and profuse sweat may be worth consideration during prescription of Formic acid. Conclusions: The proving symptoms of Formic acid could be verified clinically, but the correlation of patient-specific symptom needs cautious interpretation. Further replication on larger sample and estimation of likelihood ratio in real-time clinical practice are needed.

Keywords: Arthritis, Clinical verification, Dyspepsia, Formic acid, Homoeopathy

How to cite this article:
Manchanda R, Gupta J, Chakraborty P, Singh P, Nayan SS, Singh J P, Pradhan P K, Ramteke S, Das K C, Prasad P, Gupta P, Rakshit G, Nayak C. Formic acid : A multicentric observational homoeopathic clinical verification trial. Indian J Res Homoeopathy 2016;10:249-57

How to cite this URL:
Manchanda R, Gupta J, Chakraborty P, Singh P, Nayan SS, Singh J P, Pradhan P K, Ramteke S, Das K C, Prasad P, Gupta P, Rakshit G, Nayak C. Formic acid : A multicentric observational homoeopathic clinical verification trial. Indian J Res Homoeopathy [serial online] 2016 [cited 2022 Nov 29];10:249-57. Available from: https://www.ijrh.org/text.asp?2016/10/4/249/194320

  Introduction Top

Evidence-based Homoeopathy is a challenge for future years. In evidence-based medicine, we are looking for proof of efficacy of treatments for specific diagnoses. Evidence-based Homoeopathy is concerned with clinical verification of symptoms used in homoeopathic practice. The organization of such verification is not simple since homoeopaths use different methodologies and strategies according to their training, expertise, and clinical experience. [1] An unconfirmed proving symptom that was never verified by clinical data cannot yet be considered useful for homoeopathic practice. The system must allow verification of symptoms from remedy proving as well as clinical symptoms which will never originate from pathogenetic trials alone. [2]

The aim of this paper is to generate an enhanced drug picture of lesser known drug, Formic acid by verifying its proving symptoms and by incorporating new findings (if any) in the symptomatology of Formic acid.

Formic acid (systematically known as methanoic acid) [3] was first used as a medicine by Mr. R. Wallace of Richmond, who described its usefulness in three letters sent to Anshutz. [4] It was recommended to the homoeopathic fraternity by Dr. John Henry Clarke for cases of varicose veins, polypi, and catarrh. [4],[5] Since his time, no comprehensive study has been done to extend further the therapeutic utility. Assuming the clinical importance of the drug and keeping in mind the nonavailability of probable pathogenesis, a systematic proving of Formic acid, with randomized, double-blind, placebo-controlled technique was conducted by Central Council for Research in Homoeopathy (CCRH) [6] followed by its clinical verification to ascertain its therapeutic usefulness. Council took up its proving in 1980-1981 and after that verification was done by the council to enhance its therapeutic utility.


Chemical symbol: HCOOH [7]

Mol. Wt.: 46.03 [7]

Synonyms: English: Formic acid[7]

French: Acide formique [7]

German: Ameisensaure [7]

Formic acid is the simplest carboxylic acid. [3] It is a colorless liquid, having a pungent acid odor, and a burning taste; it crystallizes at 0°C and boils at 100°C; soluble in all proportions in water, alcohol, or glycerin. Its specific gravity is 1.23. When applied to the skin, it produces a burning sensation and even blisters. [7]

It is an important intermediate in chemical synthesis and occurs naturally, most famously in the venom of bee and ant stings. The principal use of Formic acid is as a preservative and antibacterial agent in livestock feed. [3] Metabolism of methanol, methyl ethers, esters, and amides gives rise to Formic acid. This acid is an inhibitor of the mitochondrial cytochrome oxidase causing histotoxic hypoxia. [8] This acid was first obtained by the distillation of ants, by Samuel Fisher (Lavoisier). [9]

Formic acid is found in certain caterpillars, and doubtless, the "bombic acid,0" Lavoisier mentions as being obtained from silkworm larva, was impure Formic acid. Later, F. Will has shown that the fluid in the hairs of a species of caterpillar, which causes inflammation of the skin when handled and the poisoning by the sting of some insects, is due to the Formic acid present. It has also been demonstrated that the stinging hairs of the nettle, Urtica urens, and Urtica dioica contain this acid. Formic acid is also found in pine tree leaves and in the blood, bile, urine, perspiration, and muscular tissues of man. [9]

The place of Formic acid in medicine and chemistry is a great and growing one. In the form of tincture of ants, Formica rufa, has a distinct place in homoeopathic practice. [4] Formic acid in small doses increases muscular strength and resistance to fatigue. In prescribing, Clarke orders an ounce or two of a solution of Formic acid in the proportion of one part of the acid to eleven parts of distilled water. Of this, one teaspoonful is taken in a tablespoonful of water after food once or twice daily. [5] In cases of acute rheumatic fever and acute gonococcal arthritis, Formic acid 6X, 1 cc., every 6 days showed splendid results. [10]

The primary objective of the study was to clinically verify the symptomatology of the drug as observed during proving or as mentioned in other literature. The secondary objective was to ascertain the clinical symptoms that did not appear during the proving but were improved in the patients after its administration, either completely or partially. The study of Formic acid was started in June 2010 and continued until March 2014 at 9 research centers of CCRH across India.

  Methods Top

Study Design

Multicentric observational clinical verification study was conducted at Central Research Institute, Noida (Uttar Pradesh), Homoeopathic Drug Research Institute, Lucknow (Uttar Pradesh), Regional Research Institute (H), Puri (Odisha), Regional Research Institute (H), Shimla (Himachal Pradesh), Regional Research Institute (H), Gudivada (Andhra Pradesh), Regional Research Institute (H), Imphal (Manipur), Dr. Anjali Chatterjee Regional Research Institute (H), Kolkata (West Bengal), Clinical Research Unit (H), Port Blair (Andaman and Nicobar Islands), and Clinical Verification Unit, Patna (Bihar) from June 2010 to March 2014.


Participants having symptomatological similarity Formic acid and from all age groups irrespective of sexes were included in the study. Exclusion criteria were clinical presentations not corresponding with the medicine and the patients who were on regular medication for any systemic disease. Patients who were on any medication for any "acute" purpose, 1 week before being enrolled in the study, were put on a washout period of 7 days. Informed written consent was obtained from the eligible patients or from the guardians in case of minors before initiating the study.

Data Sources/Measurement

At the baseline, the symptoms were repertorized using a repertory, prepared for this purpose by the council to aid the investigator in the selection of an appropriate medicine and subsequently confirmed from the Materia Medica. This was prepared specially for the study comprising the proving symptoms of the drug, to find out the similarity of Formic acid with the symptoms collected. Formic acid was prescribed according to the similarity of symptoms. Study medicine was procured from the licensed pharmacy in various potencies, namely 6C, 30C, 200C, and 1M.

Thus, if Formic acid was found indicated for the patient as per the drug picture recorded, [9] it was prescribed in 6C potency thrice a day. If it was not indicated, the patient was excluded from the study and treated in the general OPDs of the respective research institutes/units. The changes in presenting symptoms and signs were recorded during the follow-up visits. If there was any kind of improvement, medicine was stopped and was followed by placebo. If there was no change in symptoms and signs even up to 7 days, the next higher potencies such as 30C, 200C and 1M were prescribed as per the need of the case and in accordance with homoeopathic principles. If no change was observed even after the change of potencies, the case was closed and considered as a clinical failure.

Sample Size

A total of 6210 patients were screened from the OPDs of nine centers of CCRH. Out of this, 5940 cases who did not meet the inclusion criteria were excluded from the study. Two hundred and seventy patients were enrolled having similar symptomatology with Formic acid and meeting the prespecified eligibility criteria. Of these, four dropped out and 266 cases were analyzed [Figure 1].
Figure 1: The study flow diagram

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Statistical Method

The data of all the cases were collected and compiled in specially designed Excel spreadsheet and thereafter analyzed. Data were presented in number, percentage, mean, and standard deviation. Prevalence of the symptoms in the responding and nonresponding population was compared using Chi-square or Fisher's exact test, keeping P < 0.05 two-tailed as statistically significant. As per protocol a minimum of two prescriptions for each symptom has been considered for enlisting.

  Results Top

A total of 270 patients were enrolled having similar symptomatology with Formic acid and meeting the prespecified eligibility criteria. Of these, four dropped out and 266 results were analyzed in the end [Figure 1].

Among the enrolled patients, 137 (51.5%) were male, rest of 129 (48.4%) were female. The mean age in years of the patients was 35.0 ± 13.2. Mean body mass index (BMI) was 23.2 ± 3.10, and most of the patients (n = 195, 74%) belonged to the normal BMI range of 18.5-24.9. Two hundred and fifty-one (94%) were married and the majority (n = 110, 44%) were homemaker [Table 1].
Table 1: Baseline information (n=266)

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Out of 266 registered cases, 215 cases (80.8%) responded to Formic acid. The clinically verified symptoms were enlisted along with the outcomes on the basis of proving records (drug proving profile generated by CCRH) and the symptoms available in other literature and also the new observations (clinical symptoms), those are not mentioned elsewhere but found to have improved after the administration of Formic acid [Table 2].
Table 2: List of symptoms verified

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Among 215 patients, a total of six different clinical diagnoses were obtained. Dyspepsia was the most frequently diagnosed condition (n = 166, 62.05%) followed by headache (n = 127, 47%) and followed by arthralgia (n = 115, 43.2%) [Table 3].
Table 3: Clinical diagnoses

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Among the proving and clinically verified symptoms, most frequently observed were:

  • Diminished appetite (n = 199, prevalence 92.55%, confidence interval [CI]: 87.98, 95.55)
  • Dull pain in right hypochondrium; < by motion and > by lying down (n = 166, prevalence 76.27% in responding group, 95% CI: 69.92-81.68)
  • Heaviness of head in morning from 6.30 a.m. to 8.00 a.m. (n = 131, prevalence 59.06% in responding group, 95% CI: 52.16, 65.65)
  • Pain in left leg as if sprained (n = 120, 53.95% prevalence in responding group, 95% CI: 47.05-60.71)
  • Desire for onions (n = 82, 38.13% prevalence in responding group, 95% CI: 31.69-45.02)
  • Diminished thirst was observed in 69 patients in responding group with 32.09% prevalence and 95% CI: 25.99, 38.84
  • Sixty-seven cases of yellow coated tongue were observed in responding group (31.16% prevalence, CI: 25.13, 37.88
  • Nocturnal seminal emissions without dreams, followed by weakness (n = 48, 22.32% prevalence in responding group, 95% CI: 17.17, 28.60)
  • Cramp-like pain in lower abdomen before menstruation, better after onset of menstrual flow (n = 31, 14.41% prevalence in responding group, 95% CI: 10.15-20.0) [Table 2].

Among the newly observed symptoms, patients who responded positively were either chilly (n = 74, 34.4% prevalence in responding population, 95% CI: 28.14-41.23) or sensitive to both extremes (n = 66, 24.18% prevalence in responding population, 95% CI: 24.7-37.4). Most widely obtained symptoms were:

  • "Clean tongue" (n = 20, 9.30% prevalence in responding population, 95% CI: 5.91, 14.20)
  • "Disturbed sleep" (n = 16, 7.4% prevalence in responding population, 95% CI: 4.45, 12.02)
  • "Loose stool" (n = 14, 6.5%, 95% CI: 3.74, 10.91)
  • Tastelessness was noticed in 13 patients (6.04% prevalence) in responding group, 95% CI: 3.4, 10.36
  • "Profuse sweat" (n = 9, 4.1 prevalence in responding population, 95% CI: 2.06, 8.06); [Table 2].

Significantly higher prevalence of the symptoms under question in the responding population than in the nonresponding population was found in case of five symptoms:

  1. Heaviness of head in the morning from 6.30 a.m. to 8.00 a.m. with chilliness (127/215 vs. 04/51; Chi-square (Yates corrected) =41.25; P = 0.001 two-tailed)
  2. Dull pain in right hypochondrium; < by motion and > by lying down (164/215 vs. 02/51; Chi-square (Yates corrected) =88.93; P = 0.001 two-tailed)
  3. Nocturnal seminal emissions without dreams, followed by weakness (48/215 vs. 03/51; Chi-square (Yates corrected) = 6.17; P = 0.01 two-tailed)
  4. Pain in left leg as if sprained (116/215 vs. 04/51; Chi-square (Yates corrected) =33.5; P = 0.001 two-tailed)
  5. Chilly patient (74/215 vs. 13/51; Chi-square (Yates corrected) = 1.11; P = 0.29 two-tailed)
  6. Easily angered (10/215 vs. 02/51; Chi-square (Yates corrected) = 0.05; P = 0.82 two-tailed).

However, as far as the peculiarity of the symptoms, according to their prevalence in responding population, are considered, the first five may be segregated further and may be deemed as the most promising symptoms for future research [Table 4].{Table 3}

  Discussion Top

During this study, eleven symptoms of Formic acid were verified, which were from the proving of the medicine conducted by the Council. Alongside, some new symptoms were identified as clinically associated symptoms, improved wholly or partially, or showing improvement in the main complaint. Many symptoms showed improvement of 75% or higher [Table 2].

The main spheres of action of Formic acid were head, stomach, abdomen, male genitalia, female genitalia, and extremities. Most frequently encountered clinical conditions found to be improved were dyspepsia (164 improved out of 166), headache (127/131), arthritis (108/115), spermatorrhea (42/58), varicose veins (17/19), and lipoma (3/8). Apart from these conditions, Formic acid showed improvement in cases of dysmenorrhea, menorrhagia, amebiasis, and lymphadenitis also.

Formic acid, though belonging to one of the major group (acid group) of homoeopathic medicines, has always remained a lesser known and lesser used drug. Traditionally, also Formic acid was rarely employed as a medicine; it was only used externally as a local irritant, in sluggish capillary circulation, in certain painful affections, and in enfeebled or paralytic conditions of the limbs.

Homoeopathically, it was used by John Henry Clarke in treating cases of chronic arthritis successfully. In spite of this, Formic acid still remained a lesser known drug. Our study confirmed its use in cases of arthritis once again. Along with this, our study shows that it may also be used in other conditions such as dyspepsia, headache, and spermatorrhea as a good number of patients of these conditions were found to be improved by this medicine. Strikingly, all the 19 patients (100%) suffering from varicose veins improved after treatment. Apart from this, the newly emerged general symptoms may offer promising help while considering prescribing Formic acid. These findings are probable and need confirmation through clinical observations.

The action of Formic acid on extremities was marked with symptoms such as pain in the left leg as if sprained, thus confirming one of the symptoms available in literature, i.e., varicose veins in the left leg. Besides this, some symptoms such as heaviness of head in the morning from 6.30 a.m. to 8.00 a.m., heaviness in abdomen, dull pain in right hypochondrium, flatulence at night, desire for onions, yellow coated tongue, and nocturnal seminal emissions emerged as important pathogenesis of Formic acid. Statistical significance in these symptoms increases the probability of the drug in curing such illness in clinical practices. Moreover, this study also confirms the use of Formic acid in helping cases of chronic arthritis.

Apart from the above observations, a group of valuable symptoms also emerged reflecting the picture of the drug and thereby widening the probable scope of its therapeutic applicability. Those were loose stool, desire for spicy things, clean tongue, tastelessness, profuse sweat, and disturbed sleep. As regards thermal modality, most of the patients were found to be either chilly or sensitive to extremes. Obtained mental features were irritability and easily angered. These may be considered as useful clinical concomitants, to prescribe the medicine. Moreover, the overall results generated were contributed by different study sites, indicating enhanced generalizability of the study findings. However, being an observational trial, this study cannot address the threats to various external and internal validity issues. Several weaknesses should be taken into account when considering the results of this research. Several sources of bias could influence the findings. In a retrospective work of this kind, it is quite difficult to assess when a patient has had a positive evolution, and it is much more difficult to attribute it to the treatment. [11]

Another possible source of bias is the difficulty in assessing the presence of symptoms in patients' records because the mere mention of the symptoms in them does not mean necessarily that they were really present in the patients nor that they were strong enough to be considered as medicine indicators. [11] Furthermore, we compared between responding and nonresponding patients for one medicine. This way, we can only get some idea of symptoms that can be further investigated. These could be of great value when compared with similar data of other medicines. However, the prevalence of symptoms should preferably be compared with the whole population.

The research protocol should have anticipated and kept provision to address the issues related to spontaneous recovery of the symptoms under question, for example, using modified Naranjo criteria. However, this observational trial, being exploratory in nature, cannot evaluate the same. Therefore, assessment of likelihood ratio (LR) of symptoms to be used as a rational means for detecting indicators to homoeopathic medicines. Prospective multicenter research of real prevalence and LR of symptoms should be carried out on to tune homoeopathic medicines' knowledge and more important, to improve prescription accuracy and clinical results. [11]

  Conclusions Top

This study was conducted to clinically verify the "symptomatology" of Formic acid by ascertaining the symptoms improved during verification. This paper generated a list of clinically verified symptoms of Formic acid and warrants further evaluation using enhanced methodological rigor. On many occasions, a limited number of prescriptions was generated for specific symptoms making interpretation difficult. For clinical data, the improvement should consist of using data from prospective, multicentered research. The symptoms with low prevalence need a greater number of cases to establish substantial LR. The implementation of LR indicating the increase (or decrease) of the likelihood that a medicine will be effective if a certain symptom is present (or absent). [12] The use of LR leaves less room for speculation and will enable more accurate and quantitative description of strength of the probable or claimed characteristic symptoms of the drug, based on empirical evidence instead of assumption. However, all these results should be considered as provisory and need confirmation through prospective research of real prevalence to the knowledge of medicines and more importantly, to increase posterior chance of correct selection of medicine, improve prescription accuracy and clinical outcomes. The causal association can be tested prospectively and systematically in all cases using modified Naranjo criteria in future studies.


The authors sincerely acknowledge Dr. Vikram Singh, Former Deputy Director, CCRH and Dr. Krishna Singh, Former Assistant Director, CCRH, for their contribution in monitoring of project during the study. We are thankful to all program officers of the Institutes and units, where project was going on, for their administrative support. We are thankful to Mrs. Maya Padmanabhan, Statistical Assistant, CCRH, for her help in statistical analysis of the study. Last but not the least, we are thankful to all the patients for their participation in the study.

Financial Support and Sponsorship

The study has been funded by Central Council for Research in Homoeopathy, an autonomous organization under Ministry of AYUSH, Government of India.

Conflicts of Interest

There are no conflicts of interest.

  References Top

Van Wassenhoven M. Towards an evidence-based repertory: Clinical evaluation of Veratrum album. Homeopathy 2004;93:71-7.  Back to cited text no. 1
Van Wassenhoven M. Third Edition of LMHI Guidelines on Clinical Verification of Homeopathic Symptoms. Available from http://audesapere.in/esouvenir/files/e2dd4_2013_Guidelines_Clinical_verif_hom_symptoms_third_edition.pdf. [Last accessed on 2016 June 10 at 02:15 pm].  Back to cited text no. 2
Formic Acid. Available from: https://www.pubchem.ncbi.nlm.nih.gov/compound/formic acid. [Last accessed on 2015 November 12 at 02:15 pm].  Back to cited text no. 3
Anshutz EP. Formic acid. New Old and Forgotten Remedies. 2 nd ed. New Delhi: B. Jain Publishers (P) Ltd.; 1996. p. 201-14.  Back to cited text no. 4
Murphy R. Formic acid. Lotus Materia Medica. 2 nd Revised Edition. New Delhi: B. Jain Publishers (P) Ltd.; 2009. p. 712.  Back to cited text no. 5
Central Council for Research in Homoeopathy. Formic acid. Homoeopathic Drug Provings. New Delhi: CCRH; 2005. p. 57.  Back to cited text no. 6
Varma PN, Indu V. Encyclopaedia of Homoeopathic Pharmacoepia. 3 rd ed., Vol. II. New Delhi: B. Jain Publishers (P) Ltd.; 2002. p. 1136.  Back to cited text no. 7
Liesivuori J, Savolainen H. Methanol and formic acid toxicity: Biochemical mechanisms. J Basic Clin Pharmacol Toxicol 1991;69:157-63. Available from http://www.ncbi.nlm.nih.gov/pubmed/1665561. [Last accessed on 2015 August 02 at 03:15 pm].  Back to cited text no. 8
Anonymous. Available from http://www.henriettes-herb.com/eclectic/kings/acidum-form.html. [Last accessed on 2015 December 20 at 11:00 am].  Back to cited text no. 9
Boericke W. Formic acid. Boericke′s New Manual of Homoeopathic Materia Medica with Repertory. 3 rd Revised and Augmented. 9 th ed. New Delhi: B. Jain Publishers (P) Ltd.; 2007. p. 259.  Back to cited text no. 10
Eizayaga JE, Pozzi MI, Canan MC, Saravia L. Prevalence and likelihood ratio of symptoms in patients with good therapeutic response to Lycopodium clavatum. A retrospective study. Homeopathy 2016;105:78-83.  Back to cited text no. 11
Rutten AL, Stolper CF, Lugten RF, Barthels RW. Repertory and likelihood ratio: Time for structural changes. Homeopathy 2004;93:120-4.  Back to cited text no. 12


  [Figure 1]

  [Table 1], [Table 2], [Table 3], [Table 4]


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