I am currently suffering a sore throat. I have purchased some Betadine (gargleable iodine) which I believe and hope actually helps reduce the extent of the infection.

At the risk of derision, I will confess I have also purchased Strepsils (antibacterial throat lozenges) which I believe is mostly a sugar-pill placebo, but it is sweet, distracting from the pain and gives me something to do to feel in control, while I wait for my immune system to get around to dealing with the invaders.

The Strepsils pack admits:

The efficacy of an antibacterial agent in lozenges in reducing the severity or duration of throat infections has not been clinically established.

This suggests "We don't know yet whether this works." I am wondering if the science is actually further progressed than the company is admitting. Should this read "Large-scale experiments have shown throat lozenges are no better than placebo. We know they don't make any noticeable difference." instead?

  • Questions based on what others "should" do promote answers that contain opinion and are not constructive to this site. Anyway, if strepsils did as you say, the consumers wouldn't even obtain much placebo benefit anymore rendering the tablets useless. Placebo effect is a real effect, so the tablets do make a difference, provided they don't say they are based on the placebo. – Kenshin Jan 5 '13 at 6:19
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    That said, there is evidence to suggest that strepsils do more than a placebo, ncbi.nlm.nih.gov/pubmed/20142339. – Kenshin Jan 5 '13 at 6:21
  • @Chris: You raise some interesting points. Perhaps my wording could be improved: I don't mean "should" in the sense of "morally ought to" here - as you suggest, that will lead to opinions. I just mean "Is this a more accurate statement that would give me, the consumer, a more correct understanding?" The degree to which the placebo effect is "real" (as opposed to regression to mean, misremembering, etc.) is complex, and the ethics of lying to patients is also complex. – Oddthinking Jan 5 '13 at 8:27
  • The active ingredients in (Australian) Strepsils are: Dichlorobenzyl Alcohol and Amylmetacresol. This paper shows it has some antiviral activity (e.g. against influenza A, but not rhinoviruses) in vitro. – Oddthinking Jan 5 '13 at 8:41
  • @Oddthinking: however, strepsil are marketed as antibacterial (note "strep" in the name) – nico Jan 5 '13 at 9:01


My packet of strepsils contains a leaflet saying each lozenge contains

  • 2,4-Dichlorobenzyl alcohol 1.2 mg
  • Amylmetacresol 0.6 mg
  • Levomenthol 8.0 mg.

2,4-Dichlorobenzyl alcohol and Amylmetacresol

A throat lozenge containing amyl meta cresol and dichlorobenzyl alcohol has a direct virucidal effect on respiratory syncytial virus, influenza A and SARS-CoV.

There's evidence the ingredients are effective at killing some viruses (e.g. in mucus but perhaps not in cells?) Therefore whilst effective and working in some sense, it may not reduce the length or severity of the infection.

We conclude that, formulated as a lozenge, the mixture could have significant effects in reducing the infectivity of certain infectious viruses in the throat and presumably in cough droplets, thus reducing, theoretically, opportunities for person-to-person transmission.

You're helping your friends and family?


Also, if I correctly understand Local anaesthetic activity of (+)- and (-)-menthol, the third ingredient, levomenthol, may reduce the perceived severity of the symptoms (though having no effect on the viruses)

If you seek a mild anaesthetic effect, the lozenges may be effective (to some extent).

  • This question has 2500 views, but only 3 upvotes on this high-quality answer? Give RedGrittyBrick some love! – Oddthinking Jan 6 '15 at 14:56

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