Protocol development in integrative medicine is not typically a simple process. Individuals require individualized care, and what works for one patient may not work for another.

To establish these protocols, we first developed a Rating Scale that could be used to discern the rigor of evidence supporting a specific nutrient’s therapeutic effect.

The following protocols were developed using only A through C-quality evidence.

Qualifying studies
Minimum requirements
Systematic review or meta-analysis of human trials
RDBPC human trials
2+ studies and/or 1 study with 50 + subjects
RDBPC human trials
1 study

Seasonal occurrences of cold and flu are to be expected. Targeting the immune system during this time has the potential to help decrease the frequency, severity, or duration of cold and flu symptoms. Decreasing the risk of developing a cold or flu is possible through prophylactic supplementation, especially among high-risk populations, such as in children, the elderly, or those with compromised immune systems.

In the event a cold or flu does occur, the desired focus of supplementation may shift to decreasing the duration and severity of symptoms. Zinc may be considered in this case; when given during the initial 24 hours of symptom onset, it has been shown to reduce the number of patients with symptoms after one week. (Singh 2015) Vitamin C is another popular remedy to decrease the length of a cold and has the potential to decrease duration by approximately half a day. (Ran 2018)

The ingredients present in the protocol below reflect research findings that demonstrate efficacy when used prophylactically and therapeutically to support physiological immune function in regards to cold and flu.

Vitamin C

Adults: 1 g daily as an ongoing maintenance dose, (Hemila 2013)(Johnstone 2014)(Ran 2018) or 3 to 4 g daily at the onset of symptoms and for the duration of illness (Hemila 2013)(Ran 2018)

Children: 1 to 2 g daily as an ongoing maintenance dose (Hemila 2013)

  • Reduces the duration of the common cold by approximately a half-day, (Ran 2018) or by 8% in adults and by 14-18% in children (Hemila 2013)
  • Reduces time of confinement by approximately six hours and fever duration by approximately a half-day, relieves chest pain and chills by approximately eight hours when given an extra therapeutic dose at the time of onset of cold (Ran 2018)
  • Improves antimicrobial and natural killer (NK) cell activities, lymphocyte levels, chemotaxis, delayed T cell responses, sympathetic nervous response, and induces anti-reactive oxygen species activity (Ran 2018)
  • Decreased duration of cold by 59% and increased weekly activity levels by 39.5% when compared to placebo in otherwise healthy adult males (Johnstone 2014)

For more information on the uses of Vitamin C in other conditions, please refer to the Vitamin C reference guide.

Vitamin C in the Fullscript catalog

American ginseng (Panax quinquefolius)

400 mg, once per day, minimum 8-16 weeks in healthy adults as a preventative measure  (McElhaney 2006)(Predy 2005)(Seida 2011)

  • Reduces the duration of colds or acute respiratory infections by approximately 5-6 days (McElhaney 2006)(Seida 2011)
  • Reduces the incidence of colds by 25%, the incidence of influenza and respiratory syncytial virus, and the relative risk of respiratory symptoms by 48% (McElhaney 2006)(McElhaney 2004)(Predy 2005)
  • Reduces total symptom severity score for sore throat, runny nose, sneezing, nasal congestion, malaise, fever, headache, hoarseness, earaches, and cough (Predy 2005)
American ginseng in the Fullscript catalog

Echinacea purpurea

Prevention: 0.9 mL, three times per day (equivalent to 2400 mg of extract), minimum 4 months (Jawad 2012

Acute: Up to 4.5 mL liquid extract (equivalent to 4000 mg), once per day at the first stage of cold development (Jawad 2012)  

  • Reduces the relative risk of cold development by 10-58% (Karsch-Völk 2014)(Schoop 2006)(Shah 2007)
  • Reduces days with symptoms by 26% (1.4 days)(Jawad 2012)(Shah 2007) and symptom scores by 23% (Goel 2004)
  • 52% fewer patients requiring concomitant use of aspirin, paracetamol, or ibuprofen (Jawad 2012)
  • Reduces the incidence of cumulative viral infections by 26% and recurring infections by 59%, including influenza virus and parainfluenza virus (Jawad 2012)
  • Increases associated counts for white blood cells, monocytes, neutrophils, and natural killer cells, and suppresses superoxide production in the later phase of the cold by neutrophils  (Goel 2005)
Echinacea purpurea in the Fullscript catalog


75-100 mg of elemental zinc as zinc acetate or zinc gluconate lozenges, once per day, within 24 hours of the onset of common cold symptoms, minimum 1 to 2 weeks cold (Hemila 2017)(Hemila et al. 2017)(Hemila 2016)(Hemila 2015)(Singh 2015)

  • Reduces cold duration by 33%, (Hemila 2017) or by approximately 1.65 to 3 days in healthy adults cold (Hemila et al. 2017)(Hemila 2016)(Prasad 2008)(Singh 2015)(Science 2012)
  • Zinc acetate equivalently reduces the duration by 40% and zinc gluconate reduces the duration by 28%, (Hemila 2017) while other sources indicate greater efficacy with zinc acetate in healthy adults (Science 2012)
  • Reduces the incidence of cold symptoms after 5-7 days in healthy adults and children (Hemila et al. 2017)(Singh 2015)
  • Reduces the duration of muscle soreness by 54%, cough by 46%, voice hoarseness by 43%, nasal congestion by 37%, nasal discharge by 34%, scratchy throat by 33%, sneezing by 22%, and sore throat by 18% in healthy adults (Hemila 2015)(Prasad 2008)
  • Reduces the incidence of common cold development, absence from school, and antibiotic use in children (Singh 2015)
  • Improves anti-inflammatory and antioxidant profile via reductions in plasma interleukin-1 receptor antagonist (IL-1ra), intercellular adhesion molecule-1 (ICAM-1), TNF-ɑ, MDA, HAE, and 8-oHdG, and increases in IL-2 mRNA in mononuclear cells in healthy adults (Prasad 2008)(Prasad 2007)
  • Reduces duration of symptoms particularly when given within the first 24 hours of symptom onset (Singh 2015)
Zinc in the Fullscript catalog


Probiotics may reduce the incidence of colds with minor effects on prevention, as well as improve influenza vaccination efficacy for A/H1N1, A/H3N2, and B strains, but is dependent on strain and population. (Kang 2013)(Lei 2017)(Yeh 2018)


Common Cold

  • 5 billion CFU of Lactobacillus acidophilus NCFM (ATCC 700396), twice per day, minimum 6 months (Leyer 2009)
    • Reduces the incidence of fever by 53%, cough by 41%, and antibiotic use by 68%
    • Reduces the duration of fever, coughing, and rhinorrhea by 32%
    • Reduces days absent from childcare by 32%


  • 10 billion CFU of Bifidobacterium animalis subs. lactis Bi-07 (ATCC PTA-4802) & Lactobacillus acidophilus NCFM (ATCC 700396), twice per day for 6 months (Leyer 2009)
    • Reduces the incidence of fever by 73%, rhinorrhea by 73%, cough by 62%, and antibiotic use by 84%
    • Reduces the duration of fever, coughing, and rhinorrhea by 48%
    • Reduces days absent from childcare by 28%


Common Cold

  • 1 billion CFU of Lactobacillus paracasei 8700:2 (DSM 13434) & Lactobacillus plantarum HEAL 9 (DSM 15312), once per day for 3 months  (Berggren 2011)
    • Reduces the incidence of developing more than one common cold episode and number of days with a cold
    • Reduces total symptom scores & pharyngeal symptoms of cold
    • Reduces B lymphocyte proliferation


  • 10 billion CFU of Lactobacillus fermentum CECT5716, once per day for 2 weeks before influenza vaccination and two weeks after (Olivares 2007)
    • Reduces the incidence of influenza 5-months after vaccination compared to vaccine alone
    • Increases natural killer cells, T-helper response, and IgA levels
  • 10 billion CFU of Lactobacillus rhamnosus GG, twice per day for 4 weeks after influenza vaccination (Davidson 2011)  
    • Increases seroprotection for the H3N2 strain during the supplementation period
  • 500 mg of Saccharomyces cerevisiae (EpiCor®), once per day for 12 weeks (Moyad 2010)(Moyad 2008)  
    • Reduces the incidence of cold/flu symptoms with or without prior vaccination
    • Reduces the duration of symptoms with prior vaccination

For more detail on probiotics and their various uses in immune function, please refer to the probiotics immune support guide.

Probiotics in the Fullscript catalog


The Fullscript Integrative Medical Advisory team has developed or collected these protocols from practitioners and supplier partners to help health care practitioners make decisions when building treatment plans. By adding this protocol to your Fullscript template library, you understand and accept that the recommendations in the protocol are for initial guidance and may not be appropriate for every patient.

View protocol in-app
  1. Berggren, A., Lazou Ahrén, I., Larsson, N., & Önning, G. (2011). Randomised, double-blind and placebo-controlled study using new probiotic lactobacilli for strengthening the body immune defence against viral infections. European Journal of Nutrition, 50(3), 203–210. (B)
  2. Davidson, L. E., Fiorino, A.-M., Snydman, D. R., & Hibberd, P. L. (2011). Lactobacillus GG as an immune adjuvant for live-attenuated influenza vaccine in healthy adults: A randomized double-blind placebo-controlled trial. European Journal of Clinical Nutrition, 65(4), 501–507. (C)
  3. Goel, V., Lovlin, R., Barton, R., Lyon, M. R., Bauer, R., Lee, T. D. G., & Basu, T. K. (2004). Efficacy of a standardized echinacea preparation (Echinilin) for the treatment of the common cold: A randomized, double-blind, placebo-controlled trial. Journal of Clinical Pharmacy and Therapeutics, 29(1), 75–83. (B)
  4. Goel, V., Lovlin, R., Chang, C., Slama, J. V., Barton, R., Gahler, R., Bauer, R., Goonewardene, L., & Basu, T. K. (2005). A proprietary extract from the echinacea plant (Echinacea purpurea) enhances systemic immune response during a common cold. Phytotherapy Research, 19(8), 689–694. (B)
  5. Hemilä, H. (2017). Zinc lozenges and the common cold: A meta-analysis comparing zinc acetate and zinc gluconate, and the role of zinc dosage. JRSM Open, 8(5), 2054270417694291. (A)
  6. Hemilä, H., & Chalker, E. (2013). Vitamin C for preventing and treating the common cold. Cochrane Database of Systematic Reviews, 1, CD000980. (A)
  7. Hemilä, H., & Chalker, E. (2015). The effectiveness of high dose zinc acetate lozenges on various common cold symptoms: A meta-analysis. BMC Family Practice, 16, 24. (A)
  8. Hemilä, H., Fitzgerald, J. T., Petrus, E. J., & Prasad, A. (2017). Zinc acetate lozenges may improve the recovery rate of common cold patients: An individual patient data meta-analysis. Open Forum Infectious Diseases, 4(2), ofx059. (A)
  9. Hemilä, H., Petrus, E. J., Fitzgerald, J. T., & Prasad, A. (2016). Zinc acetate lozenges for treating the common cold: An individual patient data meta-analysis. British Journal of Clinical Pharmacology, 82(5), 1393–1398. (A)
  10. Jawad, M., Schoop, R., Suter, A., Klein, P., & Eccles, R. (2012). Safety and efficacy profile of echinacea purpurea to prevent common cold episodes: A randomized, double-blind, placebo-controlled trial. Evidence-Based Complementary and Alternative Medicine, 2012, 841315. (B)
  11. Johnston, C. S., Barkyoumb, G. M., & Schumacher, S. S. (2014). Vitamin C supplementation slightly improves physical activity levels and reduces cold incidence in men with marginal vitamin C status: A randomized controlled trial. Nutrients, 6(7), 2572–2583. (C)
  12. Kang, E.-J., Kim, S. Y., Hwang, I.-H., & Ji, Y.-J. (2013). The effect of probiotics on prevention of common cold: A meta-analysis of randomized controlled trial studies. Korean Journal of Family Medicine, 34(1), 2–10. (A)
  13. Karsch-Völk, M., Barrett, B., Kiefer, D., Bauer, R., Ardjomand-Woelkart, K., & Linde, K. (2014). Echinacea for preventing and treating the common cold. Cochrane Database of Systematic Reviews, 2, CD000530. (A)
  14. Lei, W.-T., Shih, P.-C., Liu, S.-J., Lin, C.-Y., & Yeh, T.-L. (2017). Effect of probiotics and prebiotics on immune response to influenza vaccination in adults: A systematic review and meta-analysis of randomized controlled trials. Nutrients, 9(11). (A)
  15. Leyer, G. J., Li, S., Mubasher, M. E., Reifer, C., & Ouwehand, A. C. (2009). Probiotic effects on cold and influenza-like symptom incidence and duration in children. Pediatrics, 124(2), e172–e179. (B)
  16. McElhaney, J. E., Goel, V., Toane, B., Hooten, J., & Shan, J. J. (2006). Efficacy of COLD-fX in the prevention of respiratory symptoms in community-dwelling adults: A randomized, double-blinded, placebo controlled trial. Journal of Alternative and Complementary Medicine, 12(2), 153–157. (C)
  17. McElhaney, J. E., Gravenstein, S., Cole, S. K., Davidson, E., O’neill, D., Petitjean, S., Rumble, B., & Shan, J. J. (2004). A placebo-controlled trial of a proprietary extract of North American ginseng (CVT-E002) to prevent acute respiratory illness in institutionalized older adults. Journal of the American Geriatrics Society, 52(1), 13–19. (B)
  18. Moyad, M. A., Robinson, L. E., Zawada, E. T., Jr, Kittelsrud, J. M., Chen, D.-G., Reeves, S. G., & Weaver, S. E. (2008). Effects of a modified yeast supplement on cold/flu symptoms. Urologic Nursing, 28(1), 50–55. (B)
  19. Moyad, M. A., Robinson, L. E., Zawada, E. T., Kittelsrud, J., Chen, D.-G., Reeves, S. G., & Weaver, S. (2010). Immunogenic yeast-based fermentate for cold/flu-like symptoms in nonvaccinated individuals. Journal of Alternative and Complementary Medicine, 16(2), 213–218. (B)
  20. Olivares, M., Díaz-Ropero, M. P., Sierra, S., Lara-Villoslada, F., Fonollá, J., Navas, M., Rodríguez, J. M., & Xaus, J. (2007). Oral intake of Lactobacillus fermentum CECT5716 enhances the effects of influenza vaccination. Nutrition, 23(3), 254–260. (B)
  21. Prasad, A. S., Beck, F. W. J., Bao, B., Fitzgerald, J. T., Snell, D. C., Steinberg, J. D., & Cardozo, L. J. (2007). Zinc supplementation decreases incidence of infections in the elderly: Effect of zinc on generation of cytokines and oxidative stress. The American Journal of Clinical Nutrition, 85(3), 837–844. (B)
  22. Prasad, A. S., Beck, F. W. J., Bao, B., Snell, D., & Fitzgerald, J. T. (2008). Duration and severity of symptoms and levels of plasma interleukin-1 receptor antagonist, soluble tumor necrosis factor receptor, and adhesion molecules in patients with common cold treated with zinc acetate. The Journal of Infectious Diseases, 197(6), 795–802. (B)
  23. Predy, G. N., Goel, V., Lovlin, R., Donner, A., Stitt, L., & Basu, T. K. (2005). Efficacy of an extract of North American ginseng containing poly-furanosyl-pyranosyl-saccharides for preventing upper respiratory tract infections: A randomized controlled trial. Canadian Medical Association Journal, 173(9), 1043–1048. (B)
  24. Ran, L., Zhao, W., Wang, J., Wang, H., Zhao, Y., Tseng, Y., & Bu, H. (2018). Extra dose of vitamin c based on a daily supplementation shortens the common cold: A meta-analysis of 9 randomized controlled trials. BioMed Research International, 2018, 1837634. (A)
  25. Schoop, R., Klein, P., Suter, A., & Johnston, S. L. (2006). Echinacea in the prevention of induced rhinovirus colds: A meta-analysis. Clinical Therapeutics, 28(2), 174–183. (A)
  26. Science, M., Johnstone, J., Roth, D. E., Guyatt, G., & Loeb, M. (2012). Zinc for the treatment of the common cold: A systematic review and meta-analysis of randomized controlled trials. Canadian Medical Association Journal, 184(10), E551–E561. (A)
  27. Seida, J. K., Durec, T., & Kuhle, S. (2011). North American (Panax quinquefolius) and Asian Ginseng (Panax ginseng) preparations for prevention of the common cold in healthy adults: A systematic review. Evidence-Based Complementary and Alternative Medicine, 2011, 282151. (A)
  28. Shah, S. A., Sander, S., White, C. M., Rinaldi, M., & Coleman, C. I. (2007). Evaluation of echinacea for the prevention and treatment of the common cold: A meta-analysis. The Lancet Infectious Diseases, 7(7), 473–480. (A)
  29. Singh, M., & Das, R. R. (2015). Zinc for the common cold. Cochrane Database of Systematic Reviews, 4, CD001364. (A)
  30. Yeh, T.-L., Shih, P.-C., Liu, S.-J., Lin, C.-H., Liu, J.-M., Lei, W.-T., & Lin, C.-Y. (2018). The influence of prebiotic or probiotic supplementation on antibody titers after influenza vaccination: A systematic review and meta-analysis of randomized controlled trials. Drug Design, Development and Therapy, 12, 217–230. (A)