Do Over-The-Counter Portable Oxygen Concentrators Actually Work? The Results of a COPD Foundation Study

Posted on February 07, 2023   |   

This article was written by Michael W. Hess, MPH, RRT, RPFT

In 2021, our Oxygen360 team noticed that online retailers were selling machines listed as “portable oxygen concentrators (POCs).” Many POCs are a good way for many people to stay mobile and active. However, they are not a good fit for everyone. They use a type of oxygen delivery called pulse dosing to conserve oxygen. This is different than the continuous flow from a regular concentrator. They are not able to provide high liter flow rates for people who need lots of oxygen during exercise or activity. Medicare and other insurance companies are not always willing to pay for them. That means they can be very expensive to get. Finally, they should always be prescribed by a licensed health care provider.

The machines available online were different. They only cost a few hundred dollars, a fraction of what the standard models cost. They claimed that they could provide five, six, even seven liters a minute of continuous flow, far more than any other on the market. Best of all, they could be ordered without a prescription, lowering the number of paperwork hoops someone had to jump through. Their advertising was slick and professional. People in white coats were seen alongside people wearing nasal cannulas. Those with cannulas were seen living their best lives thanks to the freedom these machines seemed to provide. It seemed almost too good to be true. Looking at the fine print, there were some disclaimers that the statements had not been evaluated by the Food and Drug Administration (much like one might see on the label of a nutritional supplement). Those disclaimers meant that the machines themselves had not gone through any kind of FDA testing for safety or effectiveness. Far from being medical devices like true POCs, these machines seemed to be no more than fancy air compressors. But these were buried far down in the descriptions, easy to overlook.

The COPD Foundation immediately took action against these “noncentrators,” writing a position statement against the sale of these machines. We also created a petition so the community could also ask these retailers to stop selling them. But we also knew that to make our case more strongly, we would need evidence. We started looking at ways we could prove that these machines were making false claims and that they could be putting people at risk.


One of the COPD Foundation board members, Dr. Richard Casaburi, is a researcher at Harbor-UCLA Medical Center in California. He and his team had previously created a device that simulates metabolism in the lung. That allowed the team to measure how much oxygen would make it into the bloods, which showed how effective an oxygen device would be. Dr. Casaburi came up with a strategy to test some of the noncentrators. He and his team offered to donate their time to the project.

We then picked three machines being sold as portable oxygen concentrators from a large online retailer and had them shipped to Dr. Casaburi’s laboratory. As soon as the noncentrators arrived, some of the false marketing claims were obvious. One of them had no battery, which meant it was only portable in the sense that someone could pick it up and move it somewhere else. We also noticed that within days of ordering each machine, they disappeared from the retailer’s website. This would make it very hard for someone to follow up with customer service. We also decided to test a real POC and an oxygen tank on the simulator so that we could see what the results should be. Each piece of equipment was tested at three metabolic rates (representing low activity, medium exercise, and heavy exercise) and at each of their available settings.


The testing showed that for the most part, the noncentrators did not work as well as real oxygen equipment. The machine without a battery did raise the amount of oxygen in the lung spaces slightly on its lowest setting (about the same as one liter per minute), but higher settings showed no increase in oxygen level. One machine did not increase oxygen levels at all. The team thought it might have been broken but continued testing it because someone buying it would have no way to know. The instruction manual for that machine also said it produced only 28% pure oxygen. This is far below oxygen made by true concentrators, which is usually over 90% pure.

The third machine did actually increase oxygen levels somewhat. It delivered oxygen with a pulse dose, but at lower settings (around what someone needing one or two liters per minute would use) the team measured higher oxygen levels during the low and medium activity testing. The increase was still lower than what the true POC and oxygen tank gave, but we could not rule out that someone might benefit from this machine in some way.


We feel that two of the three oxygen devices sold online without a prescription were not at all appropriate for someone needing long-term oxygen therapy. One machine did work a little but might not be enough for someone active. To be fair, the study did have several limitations. It was done in a laboratory on a simulator. Real lungs may work differently. We also only looked at one “real” POC, so these noncentrators may be able to keep up with others. We also did not look at every machine available for sale, so some others may work better. However, we are confident the results of this study prove that people should be very cautious when it comes to buying oxygen equipment without a prescription. We also feel that health care professionals should be aware of these machines and warn their oxygen therapy patients about their risks.

We would like to thank Dr. Casaburi and his team for their efforts and expertise.


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