Fumaric Acid

Fumaric Acid

Linear Formula

C4H4O4

Synonyms

boletic acid, lichenic acid, donitic acid, trans butenedioic acid, butenedioic acid, trans-1,2-ethylenedicarboxylic acid

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Fumaric acid, or trans butenedioic acid, is one of many organic acids. Fumaric acid is a weak acid that appears as a crystalline powder and is slightly soluble in ethyl ether and acetone. It is one of nine carboxylic acids that take part in the tricarboxylic acid cycle (TCA cycle), a metabolic process that produces energy. In the TCA cycle, the enzyme fumarase converts fumaric acid into malic acid (or maleic acid).

Fumaric acid is used as a food additive and food acidulant, acting as a potent flavoring agent for gelatin desserts, baking powders, and fruit juices. The organic acid also has industrial applications: it is present in coating additives, stain remover, paint additives, printing inks, drying oils, and contact lenses.

The industrial chemistry behind fumaric acid production

Fumaric acid is typically produced from maleic acid and maleic anhydride through isomerization1. However, the process drives substantial carbon emissions. For this reason, scientists have sought more sustainable methods to produce fumaric acid. In turn, researchers have proposed fermentation as an alternative approach2. Many fumaric acid-producing microbes, namely Rhizopus species, exist and can provide similar titers of fumaric acid as conventional production lines3.

Fumaric acid and chemical safety

Despite their health benefits and industrial applications, fumaric acid is a hazardous chemical. The European Commission and the National Institute of Standards and Technology note that the compound can cause severe eye irritation. Upon such exposure, a person must remove contact lenses before washing to prevent serious eye irritation.

Fumaric acid esters and drug development

Fumaric acid is commonly used in cosmetic products. Fumaric acid derivatives such as fumaric acid esters (FAEs) are small molecules that can modulate the immune system and exert anti-oxidative effects4. Multiple clinical trials over the past decades demonstrate FAE’s efficacy in treating psoriasis by reducing pro-inflammatory responses5. This data culminated in a 2015 systematic review which determined that FAEs provide psoriasis relief after 12-16 weeks of treatment6.

FAEs may also reduce the risk of relapsing remitting multiple sclerosis. Phase 3 clinical trial data of dimethyl fumarate, an oral FAE, shows that FAEs can reduce relapse rates7. While scientists do not fully understand its mechanism of action, they do know that FAEs act as a prodrug of monomethylfumarate, the active compound that acts as a receptor agonist8.

Fumaric acid is also used as an ingredient in Ensitrelvir, a formulation for treating mild-to-moderate COVID-19 and asymptomatic SARS-CoV-2 infections9,10. Ensitrelvir fumaric acid has demonstrated favorable clinical outcomes and has a long half-life. Notably, COVID-19 patients taking Ensitrelvir fumaric acid tested negative for SARS-CoV-2 sooner than patients who took a placebo.

Fumaric acid in research

As of July 2023, there are 241 citations for “fumaric acid” in research publications (*excluding books and documents) on PubMed. Because many publications explore the use of fumaric acid in treating psoriasis, any basic or preclinical research program focusing on skin health and disease may benefit from metabolomics analyses to characterize the mechanism of action and inform dosing strategies for existing and novel fumaric acid-based treatments. Because fumaric acid is also a commonly used treatment in multiple sclerosis, studies seeking to understand the molecular mechanisms of the disease and patient response to treatment may consider quantifying fumaric acid and related metabolites.

References

  1. Felthouse TR, Burnett JC, Horrell B, Mummey MJ, Kuo YJ. Maleic Anhydride, Maleic Acid, and Fumaric Acid. In: Kirk-Othmer Encyclopedia of Chemical Technology. John Wiley & Sons, Ltd; 2001. doi:10.1002/0471238961.1301120506051220.a01.pub2
  2. Roa Engel CA, Straathof AJJ, Zijlmans TW, van Gulik WM, van der Wielen LAM. Fumaric acid production by fermentation. Appl Microbiol Biotechnol. 2008;78(3):379-389. doi:10.1007/s00253-007-1341-x
  3. Roa Engel CA, van Gulik WM, Marang L, van der Wielen LAM, Straathof AJJ. Development of a low pH fermentation strategy for fumaric acid production by Rhizopus oryzae. Enzyme and Microbial Technology. 2011;48(1):39-47. doi:10.1016/j.enzmictec.2010.09.001
  4. Gold R, Linker RA, Stangel M. Fumaric acid and its esters: an emerging treatment for multiple sclerosis with antioxidative mechanism of action. Clin Immunol. 2012;142(1):44-48. doi:10.1016/j.clim.2011.02.017
  5. Mrowietz U, Asadullah K. Dimethylfumarate for psoriasis: more than a dietary curiosity. Trends in molecular medicine. 2005;11(1):43-48.
  6. Balak DM. Fumaric acid esters in the management of psoriasis. Psoriasis (Auckl). 2015;5:9-23. doi:10.2147/PTT.S51490
  7. Gold R, Kappos L, Arnold DL, et al. Placebo-Controlled Phase 3 Study of Oral BG-12 for Relapsing Multiple Sclerosis. New England Journal of Medicine. 2012;367(12):1098-1107. doi:10.1056/NEJMoa1114287
  8. Mrowietz U, Morrison PJ, Suhrkamp I, Kumanova M, Clement B. The Pharmacokinetics of Fumaric Acid Esters Reveal Their In Vivo Effects. Trends in Pharmacological Sciences. 2018;39(1):1-12. doi:10.1016/j.tips.2017.11.002
  9. Mukae H, Yotsuyanagi H, Ohmagari N, et al. A Randomized Phase 2/3 Study of Ensitrelvir, a Novel Oral SARS-CoV-2 3C-Like Protease Inhibitor, in Japanese Patients with Mild-to-Moderate COVID-19 or Asymptomatic SARS-CoV-2 Infection: Results of the Phase 2a Part. Antimicrob Agents Chemother. 2022;66(10):e0069722. doi:10.1128/aac.00697-22
  10. Shimizu R, Sonoyama T, Fukuhara T, Kuwata A, Matsuo Y, Kubota R. Safety, Tolerability, and Pharmacokinetics of the Novel Antiviral Agent Ensitrelvir Fumaric Acid, a SARS-CoV-2 3CL Protease Inhibitor, in Healthy Adults. Antimicrob Agents Chemother. 66(10):e00632-22. doi:10.1128/aac.00632-22

References

1. Zgoda-Pols, J.R., et al., Metabolomics analysis reveals elevation of 3-indoxyl sulfate in plasma and brain during chemically-induced acute kidney injury in mice: investigation of nicotinic acid receptor agonists. Toxicol Appl Pharmacol, 2011. 255(1): p. 48-56.

2. Bryant, J.A., et al., The impact of an oral purified microbiome therapeutic on the gastrointestinal microbiome. Nat Med, 2026. 32(1): p. 186-196

3. McGovern, B .H., et al., SER-109, an Investigational Microbiome Drugto Reduce Recurrence After Clostridioides difficile Infection: Lessons Learned From a Phase 2 Trial. Clin Infect Dis, 2021. 72(12): p. 2132-2140.

4. Feuerstadt, P., et al., SER-109, an Oral Microbiome Therapy for Recurrent Clostridioides difficile Infection. N Engl J Med, 2022. 386(3): p. 220-229.

5. Hu, Z., et al., Targeted metabolomics reveals novel diagnostic biomarkers for colorectal cancer. Mol Oncol, 2025. 19(6): p. 1737-1750.

6. Butler, F.M., et al., Vegetarian Dietary Patterns and Diet-Related Metabolites Are Associated With Kidney Function in the Adventist Health Study-2 Cohort. J Ren Nutr, 2025.

7. Stanford, J., et al., Metabolomic Profiling and Diet Quality Scoring in a Randomized Crossover Trial of Healthy and Typical Dietary Patterns. Mol Nutr Food Res, 2025 . 69(23): p. e70271.

8. O’Connor, L.E., et al., Metabolomic Profiling of an Ultraprocessed Dietary Pattern in a Domiciled Randomized Controlled Crossover Feeding Trial. J Nutr, 2023. 153(8): p. 2181-2192.

9. Fritsch, D.A., et al., Microbiome function underpins the efficacy of a fiber-supplemented dietary intervention in dogs with chronic large bowel diarrhea. BMC Vet Res, 2022. 18(1): p. 245.

10. Leal, L.N., et al., Preweaning nutrient supply improves lactation productivity and reduces the risk of culling in Holstein cows. J Dairy Sci, 2025. 108(6): p. 5875-5888.

11. Ahsin, M., et al., Soil and pasture health underlie improved beef nutrient density determined by untargeted metabolomics in Southern US grass finished beef systems. NPJ Sci Food, 2025. 9(1): p. 151.

12. Yin, W., et al., Plasma lipid profiling across species for the identification of optimal animal models of human dyslipidemia. J Lipid Res, 2012. 53(1): p. 51-65.

13. Porter, F .D., et al., Cholesterol oxidation products are sensitive and specific blood-based biomarkers for Niemann-Pick C1 disease. Sci Transl Med, 2010. 2(56): p. 56ra81.

14. Needham, B .D., et al., Plasma and Fecal Metabolite Profiles in Autism Spectrum Disorder. Biol Psychiatry, 2021. 89(5): p. 451-462

15. Li, C., et al., Estradiol and mTORC2 cooperate to enhance prostaglandin biosynthesis and tumorigenesis in TSC2-deficient LAM cells. J Exp Med, 2014. 211(1): p. 15-28.

16. Green, P.G., et al., Metabolic flexibility and reverse remodelling of the failing human heart. Eur Heart J, 2025. 46(25): p. 2422-2433.

17. Maekawa, H., et al., SGLT2 inhibition protects kidney function by SAM-dependent epigenetic repression of inflammatory genes under metabolic stress. J Clin Invest, 2025. 135(19).

18. Wu, D., et al., Integrated screens reveal that guanine nucleotide depletion, which is irreversible via targeting IMPDH2, inhibits pancreatic cancer and potentiates KRAS inhibition. Gut, 2026.

19. Schwerdtfeger, L.A., et al., Gut microbiota and metabolites are linked to disease progression in multiple sclerosis. Cell Rep Med, 2025. 6(4): p. 102055.

20. Wu, H., et al., Microbiome-metabolome dynamics associated with impaired glucose control and responses to lifestyle changes. Nat Med, 2025. 31(7): p. 2222-2231.

21. Jacobs, J.P., et al., Cognitive behavioral therapy for irritable bowel syndrome induces bidirectional alterations in the brain-gut-microbiome axis associated with gastrointestinal symptom improvement. Microbiome, 2021. 9(1): p. 236.

22. Pietzner, M., et al., Plasma metabolites to profile pathways in noncommunicable disease multimorbidity. Nat Med, 2021. 27(3): p. 471-479.

23. Faquih, T.O., et al., Robust Metabolomic Age Prediction Based on a Wide Selection of Metabolites. J Gerontol A Biol Sci Med Sci, 2025. 80(3).

24. Scherer, N., et al., Coupling metabolomics and exome sequencing reveals graded effects of rare damaging heterozygous variants on gene function and human traits. Nat Genet, 2025. 57(1): p. 193-205.

25. Holmes, Z.C., et al., Untargeted metabolomic analysis of human milk from healthy mothers reveals drivers of metabolite variability. Sci Rep, 2024. 14(1): p. 20827.

26. Titz, B., et al., Implications of Ocular Confounding Factors for Aqueous Humor Proteomic and Metabolomic Analyses in Retinal Diseases. Transl Vis Sci Technol, 2024. 13(6): p. 17.

27. Bloom, S.M., et al., Cysteine dependence of Lactobacillus iners is a potential therapeutic target for vaginal microbiota modulation. Nat Microbiol, 2022. 7(3): p. 434-450.

28. Leimer, E.M., et al., Lipid profile of human synovial fluid following intra-articular ankle fracture. J Orthop Res, 2017. 35(3): p. 657-666.