A French Trial Suggests Hydroxychloroquine is Promising Yet Risky, but Wasn’t Randomized

A French hospital published results a few days ago of a non-randomized controlled trial testing hydroxychloroquine as a treatment for COVID-19.

This looks like both good and bad news.

The upside: 200 mg hydroychloroquine sulfate three times a day for ten days reduced the presence of the virus in nose and throat swabs to zero in 70% of the patients, whereas only 12.5% of the controls had swabs reduced to zero.

The interesting surprise: some of the patients were treated with azithromycin, an antibiotic, to prevent secondary bacterial infection. The cure rate in this subgroup was 100%.

The downside: There were 26 hydroxychloroquine-treated subjects and 16 controls. None of the controls dropped out, but six of the treated subjects dropped out.

Of the six:

  • One left early, and seemed to have gotten better.
  • One got nauseated by the drug and stopped taking it.
  • Three were transferred to intensive care.
  • One died.

That zero of 16 dropped out but 4 out of 26 dropped out either because they were transferred to ICU or died suggests this drug has a high risk profile in this context. But the cure rates, on the other hand, are impressive.

What we don't know: This wasn't randomized. The controls served as controls because they refused the drug, they were pregnant or breastfeeding, or they had an allergy or contraindication to the drug, such as retinopathy, G6PD deficiency, or QT prolongation. Perhaps the ones who refused the drug had a healthier lifestyle and were anti-drug, or were less sick and felt less desperate. Perhaps there are genetics underlying those choices, or underlying the allergies or other conditions. Perhaps estrogen is protective (also suggested by a higher infection rate in males). On the other hand, it would not appear that the control group was biased by fewer preexisting health conditions.

Since the trial wasn't randomized, we can't be very confident in a cause-and-effect relationship. We can't say for sure that it caused 15 people to get better or four people to get worse, but if we are going to say it may have made 15 people get better we have to acknowledge that it may also have made four people get worse.

This seems worth watching cautiously, but not worth rushing into.

Please Support This Service

These research updates are made possible by purchases of The Food and Supplement Guide to the Coronavirus. The guide contains my most up-to-date conclusions about what we should be doing for nutritional and herbal support on top of hygiene and social distancing for added protection. Due to the absence of randomized controlled trials testing nutritional or herbal prevention, these are my best guesses for what is likely to work without significant risk of harm, based on the existing science. Purchasing the guide is also a way to donate $9.99 toward this service of providing free research updates, as the financial support provided by the guide is what enables me to spend time staying on top of the research.


I am not a medical doctor and this is not medical advice. I have a PhD in Nutritional Sciences and my expertise is in conducting and interpreting research related to my field. Please consult your physician before doing anything for prevention or treatment of COVID-19, and please seek the help of a physician immediately if you believe you may have COVID-19.


If you aren't subscribed to the research updates, you can sign up here.


You can access an archive of these updates here.

Comments and Questions

To leave a comment or question, please useĀ the Facebook post for this newsletter.