The science behind Vagus One

Over a century of nervous-system science. Curated into one modern formula.

Vagus One was developed around established research into nervous-system function, neuronal energy, cholinergic signalling and the biological response to stress. We don't add ingredients for label appeal. Every ingredient has a defined role.

Where it starts

The foundations reach back more than a century.

From the discovery of the vagus nerve's chemical messenger to human trials of the ingredients in Vagus One. Every step leads to something in the capsule.

  1. 1921

    The vagus nerve's messenger is found.

    Otto Loewi shows that the vagus nerve signals chemically. The messenger is acetylcholine, and the work wins a Nobel Prize.

    The signal Vagus One is built around
  2. 1943

    Its recipe is worked out.

    Acetylcholine is shown to be built from choline and an acetyl group. Later work ties that acetyl group to vitamins B1 and B5.

    In the formula: citicoline, thiamine, pantothenic acid
  3. 2000s

    The ingredients are tested in people.

    Citicoline, saffron and L-theanine go through randomised, placebo-controlled human trials.

    In the formula: citicoline, saffron, L-theanine
  4. 2026

    Vagus One.

    Yona brings that biology and those ingredients together in one daily formula.

    Nerve · Signal · State
01 — The nerve

Rest. Digest. Recover. One nerve behind all three.

The vagus nerve is one of the body's main channels of brain–body communication, and a central part of the parasympathetic nervous system.

  • RestThe brake between heartbeats, and what heart-rate variability measures.
  • DigestStomach acid, and the muscular waves that move a meal onward.
  • RecoverHow the body stands down once the pressure has passed.
Explore vagus research
  1. ReviewBerthoud HR, Neuhuber WL. Functional and chemical anatomy of the afferent vagal system. Autonomic Neuroscience. 2000;85(1-3):1–17. doi:10.1016/S1566-0702(00)00215-0
  2. ReviewBonaz B, Bazin T, Pellissier S. The Vagus Nerve at the Interface of the Microbiota-Gut-Brain Axis. Front. Neurosci. 2018;12:49. doi:10.3389/fnins.2018.00049
  3. ReviewTracey KJ. The inflammatory reflex. Nature. 2002;420(6917):853–859. doi:10.1038/nature01321
  4. ReviewLaborde S, Mosley E, Thayer JF. Heart Rate Variability and Cardiac Vagal Tone in Psychophysiological Research – Recommendations for Experiment Planning, Data Analysis, and Data Reporting. Front. Psychol. 2017;08. doi:10.3389/fpsyg.2017.00213
  5. ReviewThayer JF, Åhs F, Fredrikson M, et al. A meta-analysis of heart rate variability and neuroimaging studies: Implications for heart rate variability as a marker of stress and health. Neuroscience & Biobehavioral Reviews. 2012;36(2):747–756. doi:10.1016/j.neubiorev.2011.11.009
02 — The signal

The vagus nerve communicates chemically.

Acetylcholine is a key neurotransmitter in parasympathetic signalling. Making it takes raw materials and metabolic steps that themselves depend on nutrition. Vagus One was designed around this nutritional biology.

Explore signal research
  1. Landmark discoveryLoewi O. Über humorale Übertragbarkeit der Herznervenwirkung [On the humoral transmission of the action of the heart nerve]. Pflügers Arch. 1921;189(1):239–242. doi:10.1007/BF01738910
  2. Landmark discoveryNachmansohn D, Machado AL. The formation of acetylcholine. A new enzyme: “choline acetylase”. Journal of Neurophysiology. 1943;6(5):397–403. doi:10.1152/jn.1943.6.5.397
  3. ReviewPicciotto MR, Higley MJ, Mineur YS. Acetylcholine as a Neuromodulator: Cholinergic Signaling Shapes Nervous System Function and Behavior. Neuron. 2012;76(1):116–129. doi:10.1016/j.neuron.2012.08.036
  4. ReviewBlusztajn JK, Wurtman RJ. Choline and Cholinergic Neurons. Science. 1983;221(4611):614–620. doi:10.1126/science.6867732
  5. Laboratory studyCohen EL, Wurtman RJ. Brain Acetylcholine: Control by Dietary Choline. Science. 1976;191(4227):561–562. doi:10.1126/science.1251187
  6. ReviewZeisel SH, da Costa KA. Choline: an essential nutrient for public health. Nutrition Reviews. 2009;67(11):615–623. doi:10.1111/j.1753-4887.2009.00246.x
  7. ReviewDerbyshire E. Could we be overlooking a potential choline crisis in the United Kingdom?. BMJ Nutrition, Prevention & Health. 2019;2(2):86–89. doi:10.1136/bmjnph-2019-000037
03 — The formula

Nine ingredients. Every one earns its place.

Each one chosen from peer-reviewed research for a defined role. Every ingredient, every dose, every reason.

01 · Nerve

Nutrients selected around normal nervous-system function and neuronal energy.

Nervous-system functionThiamine25 MGContributes to the normal functioning of the nervous system, and plays a fundamental role in cellular energy metabolism.View research
  1. ReviewOverton E, Emelyanova A, Bunik VI. Thiamine, gastrointestinal beriberi and acetylcholine signaling. Front. Nutr. 2025;12:1541054. doi:10.3389/fnut.2025.1541054
  2. ReviewManzetti S, Zhang J, van der Spoel D. Thiamin Function, Metabolism, Uptake, and Transport. Biochemistry. 2014;53(5):821–835. doi:10.1021/bi401618y
  3. ReviewCalderón‐Ospina CA, Nava‐Mesa MO. B Vitamins in the nervous system: Current knowledge of the biochemical modes of action and synergies of thiamine, pyridoxine, and cobalamin. CNS Neurosci Ther. 2020;26(1):5–13. doi:10.1111/cns.13207
  4. ReviewKennedy D. B Vitamins and the Brain: Mechanisms, Dose and Efficacy—A Review. Nutrients. 2016;8(2):68. doi:10.3390/nu8020068
  5. Laboratory studyJankowska‐Kulawy A, Bielarczyk H, Pawełczyk T, et al. Acetyl‐CoA and acetylcholine metabolism in nerve terminal compartment of thiamine deficient rat brain. Journal of Neurochemistry. 2010;115(2):333–342. doi:10.1111/j.1471-4159.2010.06919.x
  6. Scientific opinionEFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). Scientific Opinion on substantiation of health claims related to thiamine and energy-yielding metabolism. EFSA Journal. 2009;7(10):1222. doi:10.2903/j.efsa.2009.1222
Neuronal energyBenfotiamine200 MGA fat-soluble form of vitamin B1, studied in people for how well it is absorbed.View research
  1. Human studyXie F, Cheng Z, Li S, et al. Pharmacokinetic study of benfotiamine and the bioavailability assessment compared to thiamine hydrochloride. The Journal of Clinical Pharmacology. 2014;54(6):688–695. doi:10.1002/jcph.261
  2. ReviewLonsdale D. A Review of the Biochemistry, Metabolism and Clinical Benefits of Thiamin(e) and Its Derivatives. Evidence-Based Complementary and Alternative Medicine. 2006;3(1):49–59. doi:10.1093/ecam/nek009
Energy metabolismRiboflavin10 MGThe active form of vitamin B2. Contributes to the normal functioning of the nervous system and to the reduction of tiredness and fatigue.View research
  1. ReviewPowers HJ. Riboflavin (vitamin B-2) and health. The American Journal of Clinical Nutrition. 2003;77(6):1352–1360. doi:10.1093/ajcn/77.6.1352
  2. ReviewPinto JT, Zempleni J. Riboflavin. Advances in Nutrition. 2016;7(5):973–975. doi:10.3945/an.116.012716
  3. ReviewTardy AL, Pouteau E, Marquez D, et al. Vitamins and Minerals for Energy, Fatigue and Cognition: A Narrative Review of the Biochemical and Clinical Evidence. Nutrients. 2020;12(1):228. doi:10.3390/nu12010228
  4. Scientific opinionEFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). Scientific Opinion on the substantiation of health claims related to riboflavin (vitamin B2) and contribution to normal energy-yielding metabolism. EFSA Journal. 2010;8(10):1814. doi:10.2903/j.efsa.2010.1814
Nerve and psychological functionMagnesium60 MGContributes to normal nervous-system and psychological function. Studied in relation to stress and heart-rate variability.View research
  1. ReviewBoyle N, Lawton C, Dye L. The Effects of Magnesium Supplementation on Subjective Anxiety and Stress—A Systematic Review. Nutrients. 2017;9(5):429. doi:10.3390/nu9050429
  2. ReviewPickering G, Mazur A, Trousselard M, et al. Magnesium Status and Stress: The Vicious Circle Concept Revisited. Nutrients. 2020;12(12):3672. doi:10.3390/nu12123672
  3. Human studyWienecke E, Nolden C. Langzeit-HRV-Analyse zeigt Stressreduktion durch Magnesiumzufuhr [Long-term HRV analysis shows stress reduction with magnesium intake]. MMW - Fortschritte der Medizin. 2016;158(S6):12–16. doi:10.1007/s15006-016-9054-7
  4. Scientific opinionEFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). Scientific Opinion on the substantiation of health claims related to magnesium and electrolyte balance. EFSA Journal. 2009;7(10):1216. doi:10.2903/j.efsa.2009.1216
02 · Signal

Built around the nutritional biology involved in acetylcholine signalling.

Choline biologyCiticoline250 MGA bioavailable source of choline, a precursor involved in acetylcholine synthesis. Studied in double-blind human trials of attention and memory.View research
  1. Human studyMcGlade E, Locatelli A, Hardy J, et al. Improved Attentional Performance Following Citicoline Administration in Healthy Adult Women. Food and Nutrition Sciences. 2012;03(06):769–773. doi:10.4236/fns.2012.36103
  2. Human studyMcGlade E, Agoston AM, DiMuzio J, et al. The Effect of Citicoline Supplementation on Motor Speed and Attention in Adolescent Males. J Atten Disord. 2019;23(2):121–134. doi:10.1177/1087054715593633
  3. Human studyNakazaki E, Mah E, Sanoshy K, et al. Citicoline and Memory Function in Healthy Older Adults: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial. The Journal of Nutrition. 2021;151(8):2153–2160. doi:10.1093/jn/nxab119
  4. Human studySilveri MM, Dikan J, Ross AJ, et al. Citicoline enhances frontal lobe bioenergetics as measured by phosphorus magnetic resonance spectroscopy. NMR in Biomedicine. 2008;21(10):1066–1075. doi:10.1002/nbm.1281
  5. Human studyWurtman RJ, Regan M, Ulus I, et al. Effect of oral CDP-choline on plasma choline and uridine levels in humans. Biochemical Pharmacology. 2000;60(7):989–992. doi:10.1016/S0006-2952(00)00436-6
  6. ReviewSynoradzki K, Grieb P. Citicoline: A Superior Form of Choline?. Nutrients. 2019;11(7):1569. doi:10.3390/nu11071569
Acetyl biologyAcetyl-L-carnitine300 MGCarries acetyl groups, and is studied for its role in neuronal energy and acetylcholine biology.View research
  1. Laboratory studyWhite HL, Scates PW. Acetyl-l-carnitine as a precursor of acetylcholine. Neurochem Res. 1990;15(6):597–601. doi:10.1007/BF00973749
  2. Laboratory studyImperato A, Ramacci MT, Angelucci L. Acetyl-l-carnitine enhances acetylcholine release in the striatum and hippocampus of awake freely moving rats. Neuroscience Letters. 1989;107(1-3):251–255. doi:10.1016/0304-3940(89)90826-4
  3. ReviewREBOUCHE CJ. Kinetics, Pharmacokinetics, and Regulation of l‐Carnitine and Acetyl‐l‐carnitine Metabolism. Annals of the New York Academy of Sciences. 2004;1033(1):30–41. doi:10.1196/annals.1320.003
  4. ReviewNACZ K. Carnitine: transport and physiological functions in the brain. Molecular Aspects of Medicine. 2004;25(5-6):551–567. doi:10.1016/j.mam.2004.06.001
Coenzyme APantothenic acid100 MGThe body makes coenzyme A from it, which acetylcholine synthesis depends on. Contributes to normal mental performance.View research
  1. ReviewLEONARDI R, ZHANG Y, ROCK C, et al. Coenzyme A: Back in action. Progress in Lipid Research. 2005;44(2-3):125–153. doi:10.1016/j.plipres.2005.04.001
  2. Laboratory studyRivera‐Calimlim L, Hartley D, Osterhout D. Effects of ethanol and pantothenic acid on brain acetylcholine synthesis. British J Pharmacology. 1988;95(1):77–82. doi:10.1111/j.1476-5381.1988.tb16550.x
  3. Scientific opinionEFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). Scientific Opinion on the substantiation of health claims related to pantothenic acid and energy-yielding metabolism. EFSA Journal. 2009;7(10):1218. doi:10.2903/j.efsa.2009.1218
03 · State

Human-studied bioactives selected around calm, the stress response and resilience.

Stress resilienceSaffron30 MGStudied in randomised human trials exploring mood, sleep quality and the response to stress.View research
  1. Human studyKell G, Rao A, Beccaria G, et al. affron® a novel saffron extract (Crocus sativus L.) improves mood in healthy adults over 4 weeks in a double-blind, parallel, randomized, placebo-controlled clinical trial. Complementary Therapies in Medicine. 2017;33:58–64. doi:10.1016/j.ctim.2017.06.001
  2. Human studyJackson PA, Forster J, Khan J, et al. Effects of Saffron Extract Supplementation on Mood, Well-Being, and Response to a Psychosocial Stressor in Healthy Adults: A Randomized, Double-Blind, Parallel Group, Clinical Trial. Front. Nutr. 2021;7:606124. doi:10.3389/fnut.2020.606124
  3. Human studyLopresti AL, Smith SJ, Metse AP, et al. Effects of saffron on sleep quality in healthy adults with self-reported poor sleep: a randomized, double-blind, placebo-controlled trial. Journal of Clinical Sleep Medicine. 2020;16(6):937–947. doi:10.5664/jcsm.8376
  4. Human studyLopresti AL, Smith SJ, Drummond PD. An investigation into an evening intake of a saffron extract (affron®) on sleep quality, cortisol, and melatonin concentrations in adults with poor sleep: a randomised, double-blind, placebo-controlled, multi-dose study. Sleep Medicine. 2021;86:7–18. doi:10.1016/j.sleep.2021.08.001
  5. Human studyPachikian BD, Copine S, Suchareau M, et al. Effects of Saffron Extract on Sleep Quality: A Randomized Double-Blind Controlled Clinical Trial. Nutrients. 2021;13(5):1473. doi:10.3390/nu13051473
  6. Human studyLopresti AL, Smith SJ. The Effects of a Saffron Extract (affron®) on Menopausal Symptoms in Women during Perimenopause: A Randomised, Double-Blind, Placebo-Controlled Study. J Menopausal Med. 2021;27(2):66. doi:10.6118/jmm.21002
Calm and stress responseL-theanine150 MGStudied in human research exploring relaxation, stress and cognitive state.View research
  1. Human studyHidese S, Ogawa S, Ota M, et al. Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial. Nutrients. 2019;11(10):2362. doi:10.3390/nu11102362
  2. Human studyKimura K, Ozeki M, Juneja LR, et al. l-Theanine reduces psychological and physiological stress responses. Biological Psychology. 2007;74(1):39–45. doi:10.1016/j.biopsycho.2006.06.006
  3. Human studyWhite D, De Klerk S, Woods W, et al. Anti-Stress, Behavioural and Magnetoencephalography Effects of an l-Theanine-Based Nutrient Drink: A Randomised, Double-Blind, Placebo-Controlled, Crossover Trial. Nutrients. 2016;8(1):53. doi:10.3390/nu8010053
  4. Human studyUnno K, Tanida N, Ishii N, et al. Anti-stress effect of theanine on students during pharmacy practice: Positive correlation among salivary α-amylase activity, trait anxiety and subjective stress. Pharmacology Biochemistry and Behavior. 2013;111:128–135. doi:10.1016/j.pbb.2013.09.004
  5. Human studyYoto A, Motoki M, Murao S, et al. Effects of L-theanine or caffeine intake on changes in blood pressure under physical and psychological stresses. J Physiol Anthropol. 2012;31(1):28. doi:10.1186/1880-6805-31-28
  6. Human studyBaba Y, Inagaki S, Nakagawa S, et al. Effects of L-Theanine on Cognitive Function in Middle-Aged and Older Subjects: A Randomized Placebo-Controlled Study. Journal of Medicinal Food. 2021;24(4):333–341. doi:10.1089/jmf.2020.4803
  7. ReviewWilliams JL, Everett JM, D’Cunha NM, et al. The Effects of Green Tea Amino Acid L-Theanine Consumption on the Ability to Manage Stress and Anxiety Levels: a Systematic Review. Plant Foods Hum Nutr. 2020;75(1):12–23. doi:10.1007/s11130-019-00771-5
How we formulate

Research first. Then the capsule.

01

Chosen from the literature

Every active earns its place from published, peer-reviewed research.

02

Three layers, one formula

Nerve, Signal and State. Every ingredient has a defined role in one of them.

03

Only what earns its place

A vegan capsule holding the nine actives, and nothing else.

04

Tested, every batch

GMP manufactured and third-party tested before it reaches you.

Dr Alisha Damani David McCollum

Developed with a clinical advisory team spanning medicine and nutrition: Dr Alisha Damani, MBChB, and clinical nutritionist David McCollum. Every ingredient and dose was chosen from peer-reviewed research under their guidance.

Questions

The short answers.

What is Vagus One?

Vagus One is a daily food supplement from Yona, formulated around the nutritional biology of the vagus nerve and the wider nervous system. It contains nine ingredients in three layers, Nerve, Signal and State, and the serving is two capsules a day with a meal.

Is Vagus One backed by clinical research?

Yes. Every ingredient in Vagus One was chosen from published research: 50 peer-reviewed papers, including 19 studies in people, all listed on this page. Citicoline (250 mg) and saffron (30 mg) are included at amounts used in randomised, placebo-controlled human trials. As with most food supplements, the research is on the ingredients, and Yona's ambition is to add original human research on the complete formula.

What is in Vagus One?

Two capsules of Vagus One provide acetyl-L-carnitine 300 mg, citicoline 250 mg, benfotiamine 200 mg, L-theanine 150 mg, pantothenic acid 100 mg, magnesium 60 mg (as bisglycinate), saffron extract 30 mg, thiamine 25 mg and riboflavin 10 mg, in a vegan capsule that holds the nine actives and nothing else.

Does Vagus One stimulate the vagus nerve?

No. Breathwork, cold exposure and devices stimulate the vagus nerve. Vagus One is nutrition: it supplies nutrients and bioactives selected around the biology the nerve runs on. Stimulation and nutrition are different layers, and many people use both.

Who formulated Vagus One?

Vagus One was developed by Yona with a clinical advisory team spanning medicine and nutrition: Dr Alisha Damani, MBChB, a medical doctor, and David McCollum, a clinical nutritionist. Every ingredient and dose was chosen from peer-reviewed research under their guidance, and every batch is GMP manufactured and third-party tested.

Is Vagus One the same as Vagus+?

No. Vagus One is Yona's current daily formula. It replaced Yona's earlier product, Vagus+, in 2026.

What do customers say about Vagus One?

Yona is rated 4.6 from more than 1,000 customer reviews. In a self-reported survey of 748 Yona customers, 84% noticed less brain fog, 81% reported better digestion, 76% had more energy and 73% felt calmer. Customer experience is individual, and it is separate from the peer-reviewed research listed on this page.

What's next

And we're only getting started.

Our field is the nutritional biology of the nervous system, and Vagus One is its first expression. As Yona grows, our ambition is to contribute to that field ourselves, with original human research into vagus-focused nervous-system nutrition.

Trusted every day

The science, in two capsules a day.

4.6 from 1,000+ customer reviews

Explore Vagus One

The research on this page relates to the individual ingredients in Vagus One. Food supplements are not a substitute for a varied, balanced diet and a healthy lifestyle, and are not intended to diagnose, treat, cure or prevent any disease.