Sweetgum balls don’t contain Tamiflu’s active ingredient and there’s no evidence of an antiviral effect against COVID-19

Key takeaway

Sweetgum contains small amounts of shikimic acid, which is the starting point in the industrial manufacture of Tamiflu, a drug for treating influenza. However, there is no evidence that shikimic acid has the same effect. Tamiflu targets a specific protein found in flu viruses, so it doesn’t work against the virus that causes COVID-19, and neither does shikimic acid.

Reviewed content

Verdict:

Inaccurate

Claim:

Sweetgum balls contain the same active ingredient that Tamiflu contains, which is shikimic acid; It kills viruses including SARS-CoV-2

Verdict detail

Factually inaccurate: Shikimic acid is a starting material in the industrial manufacture of oseltamivir, marketed as Tamiflu. The two chemicals are different and don’t behave the same way. Shikimic acid isn’t considered to be an effective antiviral treatment.

See our method of evaluation

Full Claim

“[Sweetgum balls] contain the same active ingredient that Tamiflu contains, which is shikimic acid”; “It kills viruses [including SARS-CoV-2]”

A TikTok video, which was also shared on Facebook over 17,000 times, wrongly claimed that pods from sweetgum trees can be used as an antiviral treatment as it contains the same ingredient as Tamiflu and suggested that it could treat COVID-19.

Tamiflu is a treatment for influenza that works by stopping the activity of a protein found in the influenza virus called neuraminidase. Neuraminidase is important for newly-created flu viruses to escape infected cells and spread through the body.

Sweetgum trees produce hard, spiky pods known as gum balls. The video claimed that the sweetgum balls “contain the same active ingredient that Tamiflu contains, which is shikimic acid”. This claim is incorrect, as the active ingredient in Tamiflu is oseltamivir.

The manufacture of oseltamivir uses shikimic acid as a starting material^[1]. However, they are very different molecules. The process requires ten steps to chemically transform shikimic acid into oseltamivir^[1].

Oseltamivir/Tamiflu is designed to latch onto the flu virus’ neuraminidase proteins and stop them from working without significantly affecting our own proteins. This requires a very specific chemical structure. Even seemingly minor changes can dramatically alter a drug’s behavior, so we cannot assume that shikimic acid would have the same effect as oseltamivir. There have been studies into the biological activity of shikimic acid, but there doesn’t appear to be any indication of an antiviral effect^[2].

The shikimic acid used in manufacturing was sourced by purifying extracts from Chinese star anise^[1]. However, this plant contains very low amounts of shikimic acid, which acts as a bottleneck in production, leading to shortages during periods of high demand for Tamiflu^[3]. Shikimic acid is now mostly supplied through the fermentation of modified bacteria.

The TikTok video was correct in saying that sweetgum seeds contain shikimic acid^[1]. However, this is at even lower levels than star anise and is not a commercial source for Tamiflu manufacturing. The video claimed that cutting the gum balls and soaking them in vodka would release “nature’s cure”. Given that a critical industrial purification process struggles to extract enough shikimic acid from these sources, it seems unlikely that this method would be effective.

The video also makes reference to using sweetgum balls to treat COVID-19. However, as mentioned previously, Tamiflu works by targeting a specific protein in the flu virus. There is no equivalent of the neuraminidase protein in the SARS-CoV-2 virus, so the drug cannot act in the same way that it does with flu^[4]. To claim that shikimic acid can help treat COVID-19 would need evidence from research.

In summary, shikimic acid is not the active ingredient in Tamiflu. Shikimic acid is chemically altered to produce Tamiflu and will not have the same effect. The amount of shikimic acid in sweetgum balls is very low and it is difficult to extract.

REFERENCES

• 1 – Rawat et al. (2013) Expanding horizons of shikimic acid. Applied Microbiology and Biotechnology.
• 2 – Patra et al. (2020) Star anise (Illicium verum): Chemical compounds, antiviral properties, and clinical relevance. Phytotherapy Research.
• 3 – Farina and Brown (2006) Tamiflu: The Supply Problem. Angewandte Chemie.
• 4 – Robson (2020) Bioinformatics studies on a function of the SARS-CoV-2 spike glycoprotein as the binding of host sialic acid glycans. Computers in Biology and Medicine.