The common cold and influenza are infections of the respiratory tract caused by a variety of viruses.  Given that fact, antibiotics are not useful for treating these infections.  Currently, there are no antiviral medications indicated for use in the common cold. 

There are a handful of antiviral medications indicated for influenza. They are usually reserved for those at the highest risk for complications.  However, these medications have some significant limitations.  They must be started within 48 hours of the onset of symptoms and at best, reduce the duration of symptoms by 12 -24 hours.  They haven’t been shown to significantly reduce complications of influenza and have in fact, some particularly nasty side effects.  These include: nausea, vomiting, and psychiatric events 1

Should you find yourself stricken with the cold or flu, here are some natural weapons for your antiviral arsenal.




  • Elderberry extract is not only a source of potent antioxidants; it has been shown to be a potent antiviral. It accomplishes this by interfering with the invasion of cells by the influenza virus and preventing viral replication.  A study showed that 15 ml (a tablespoon) of elderberry syrup given 4 times daily for 5 days shortened the course of influenza by 4 days. 2   Just for some perspective, a typical bout of the flu lasts from 1-2 weeks, with the most severe symptoms lasting for up to 3 days. 


  • Green tea and its extracts have been shown to directly kill influenza.  As a result of its potent antiviral, antioxidant, and anti-inflammatory reactions, it can reduce the symptoms of infection. 3   Enjoy each cup with some lemon and honey to get more bang for your buck.   Make mine organic, please!


  • Olive leaf extract has also demonstrated potent antiviral and anti-inflammatory activity, reducing the duration and severity of viral illnesses.   It comes in many forms.  For instance, a tea made from olive leaf can be used as a gargle for treating viral sore throats. 4




  • Vitamin D has been found to play a significant role in the regulation of the immune system.   If you don’t know your D status, chances are it’s not good.  In that case, taking 50,000 IUs daily for 3 days and then dropping it down to 5, 000 IUs daily or so, can give your immune system the boost it needs.  Make sure you get your levels checked so that you don’t under or overshoot.


  • Vitamin C has been a source of controversy in the cold and flu world because of conflicting data regarding its efficacy.  A lot of this has to do with inappropriate dosing, both in amount and frequency.   Humans are among the extreme minority of God’s creatures that can’t make vitamin C.  Our need for this potent antioxidant increases during times of stress and illness.  For this reason, vitamin C doesn’t stick around long in a sick body and so it needs to be dosed frequently to see the desired effect.  One study showed an 85% reduction in cold and flu symptoms with what some would consider aggressive dosing (1000mg every hour for six hours, followed by 1000 mg three times a day). 5  It is nearly impossible to overdose on vitamin C, as you will get the Hershey’s squirts (diarrhea and GI upset) before that happens.   If you find yourself in this uncomfortable position, reduce the dose or the frequency. 


  • Zinc is a mineral crucial for immune function.   Zinc lozenges, taken every 2 hours while awake, can significantly reduce the duration and severity of viral infections. Long-term excessive zinc supplementation can result in copper deficiency, so don’t make this a habit.


  • Selenium is a powerful antioxidant in nearly all human tissues.  Folks with selenium deficiency have been found to be more susceptible to viral infection. 6   Consider supplementing with 100-200 mcg of selenium per day.





  • N-acetyl-cysteine (NAC) is an amino acid, the building blocks of proteins.  It is used in hospitals as a mucolytic agent (thins mucus) and to treat acetaminophen overdose.  At oral doses of 600 mg twice daily, it has been found to reduce the incidence and severity of infections with influenza.4





  • Probiotics are not only good for preventing colds and flu, but they are helpful in the treatment.   Take your probiotic daily.  Some specific organisms to look for on the label include Bifidobacterium species and Bacillus coagulans.7



This is by no means an exhaustive list of all the beneficial natural substances of use in treating viral infections.  Just as winning real wars require the cooperation of all the branches of the armed forces; the war against the cold and flu is no different.  Your attack needs to be delivered from the firm base of an optimized immune system, as discussed here in this previous blog post.  

I do hope you find this useful. 

I love to hear your feedback and field your questions in the “Comments” section below.  





  2. www.ncbi.nlm.nih.go v/pubmed/15080016


About the Author

Jason Gourlas, MPAS PA-C

For as long as he could remember, Jason has wanted to be a detective.  While serving as an Army medic, Jason realized that medicine combined detective work with his other love, science. He went through the Army PA program at Fort Sam while serving as a member of the Texas Army National Guard.  During his 22 + years in medicine, he has had a wide variety of experience in family practice, emergency medicine, neurotology (hearing and balance specialty), and surgical/trauma critical care.  For the last several years he has been studying and practicing functional and integrative medicine. He maintains certification in functional medicine through the American Academy of Anti-aging Medicine. 

About the Author

Jason Gourlas, MPAS PA-C

For as long as he could remember, Jason has wanted to be a detective.  While serving as an Army medic, Jason realized that medicine combined detective work with his other love, science.

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