Cedars-Sinai’s Innovative “Internal Ultraviolet Therapy”: An Update

7 min readSep 8, 2022


Employing UVA light to treat viruses inside the body.

I have written extensively on the Cedars-Sinai MAST Program’s Internal Utraviolet Therapy technology, which could potentially represent a major medical breakthrough in the treatment of viruses and related afflictions. The preponderance of successful outcomes in all of the pre-clinical research and the initial “pilot” clinical trial for this innovative technology suggests that researchers are extremely close to providing substantial proof of effectiveness for treating a variety of microbes and viruses (Note: the first trial required only 5 days of treatment per patient). Despite this incredible progress, mainstream media has largely ignored this breakthrough medical technology. Now one of the technology’s inventors tells us why.

I recently had the pleasure of interviewing Mark Pimentel, MD, the head of the Pimentel Laboratory and executive director of the Medically Associated Science and Technology (MAST) Program at Cedars-Sinai. In this wide-ranging Q&A session, Dr. Pimentel discussed his path from growing up in Thunder Bay, Ontario, Canada to leading one of the world’s most renowned medical research institutes. He also describes his early challenges overcoming resistance to a new approach to treating Irritable Bowel Syndrome (“IBS”), the microbiome, as well as his successes with the very innovative MAST Program and its inventions, including the internal ultraviolet therapy.

Dr. Mark Pimentel, Executive Director, Cedars-Sinai MAST Program

Before we get to the specific excerpt from the interview with Dr. Pimentel that focuses on Internal Ultraviolet Therapy, let’s take a brief look at some background information on this exciting technological invention for additional context.

Development of “Healight” by Aytu BioPharma

Certain rights to Cedars-Sinai’s now U.S.-patented Internal Ultraviolet Therapy were acquired by Aytu BioPharma (“AYTU”) in 2020 and branded as “Healight”. Unfortunately, the story of AYTU’s development of this asset is surrounded by as much controversy and complications as that faced by the Cedars-Sinai technology itself. The details of that saga could be an article in itself but can be found HERE in supporting material for a formal complaint filed with the Securities & Exchange Commission.

As far as the next stage of development of Healight, the preliminary formal notification of the next phase clinical trial start date was first published by AYTU in December 2021 through the National Institute of Health’s (“NIH”) website. Since then, the actual start date has been repeatedly pushed out, including most recently from July to September 2022, a nine-month delay from the original December 2021 date. These repeated delays in officially starting this critical trial would seem to demand an explanation from AYTU leadership, especially after what would appear to be an extremely successful “pilot” study and ongoing clinical research, yet this has not been forthcoming.

Results from the 2020 “Pilot” Trial (NIH)

AYTU also never provided public information on the initiation of the first porcine pretrial study, which was commissioned to support the pending larger human clinical trial. The study was only announced publicly in April 2022 upon its completion. AYTU has not confirmed or commented on whether the 2nd porcine study, announced in the PR, is responsible for the delay in the start of the human clinical trial. The latest example of the weak promotion efforts by AYTU for this technology can be found in an obscure publication with a very limited audience. Meanwhile, the general public remains largely unaware of this potentially game-changing, life-saving innovation.

The progress and success of the Cedars-Sinai Internal Ultraviolet Therapy were recently noted by its inventor, Dr. Ali Rezaie, in an interesting video that reiterated the prospects for this breakthrough technology. The video is behind a firewall but all that is required to access it is to provide an email registration.

Cedars-Sinai MAST Program’s Dr. Ali Rezaie

Q&A Session with Dr. Mark Pimentel

Provided below is a summarized excerpt transcribed from my recent interview with Dr. Pimentel, where he provides his insight on the MAST Program’s Internal Ultraviolet Therapy and his team’s efforts to overcome the ongoing challenges surrounding its development and commercialization.

As an accomplished scientist, when you look at all the things going on globally, pandemics, escalating cultural divisions, and climate change, what are you seeing as some of the most pressing issues from your perspective? What do we need to do better as a global civilization?

Pimentel, Mark, M.D.:
I don’t know what went wrong in the beginning but I think social media has a lot to do with it. I think people are expressing themselves more publicly because they can hide behind an icon or a persona on the Internet, and nobody holds them to account for what they’re saying or how they’re trying to rile people up. They were always there, these people, they just now have a voice, and sometimes it can be quite loud and amplifying. If I want to find somebody who likes to pet frogs in their spare time, I’ll find a thousand people on the Internet where I couldn’t find that before. You can find like-minded individuals in good and bad ways and I think that’s hurt us. I think what alarms me personally is this negativism towards science and technology. We saw that with COVID. We saw a lot of negativity.

About five or six years ago, my colleague, who happens to be Canadian and also part of the MAST Program but younger than me. I brought him on board from Calgary. His name is Doctor Ali Rezaie. He had come to me and said, what do you think about, with all this bacteria stuff we’re doing, we develop ultraviolet light to treat bacteria? Together we developed the technology where we could eliminate bacteria and infections, even the toughest infections that are resistant to the strongest antibiotics, with just 20 minutes of this ultraviolet therapy.

And then COVID hit and we said, could we kill COVID with ultraviolet? And the answer is, brilliantly! And not only that, we developed the catheter that can go into the trachea and we applied to the [Covid-19] task force for the US government. We know it ended up on [former U.S. Vice-President] Mike Pence’s desk and probably got the ears of the President. And that’s where the [infamous] ultraviolet story comes from.

And is that technology still progressing now? I know there were very famous remarks by former U.S. President Donald Trump at one [of the daily Covid-19] press conferences regarding the use of the UVA light internally but not much after that.

Pimentel, Mark, M.D.
What it led to is a small clinical trial where it prevented people from dying. We put it into humans and it worked brilliantly but the whole controversy threw the project into a tailspin that we can’t get out of because there was so much negative press about just the comments that this could even be possible.

That’s probably a crazy story that might be interesting in your piece, but it’s a proud moment because we were actually able to do it, but it didn’t manifest as well as we’d like. We’re still in communication with the FDA and we’re pushing the project forward. We’re doing the clinical trials overseas because nobody had the stomach to do it here in the US with the comments. That was what happened, but it’s still progressing. We’re still hoping to get an FDA approval. It could treat all sorts of viral infections in the lungs.

What we did learn, which is really exciting, is why you don’t get colds in the summer because the ultraviolet light applied to the trachea through the breathing tube turns the antiviral system on for the entire cells. So, they communicate to each other, and they say ultraviolet light is here. It must be summer, and they turn their antiviral system on and it really kills the virus off. We discovered a lot of really cool things that we published and it got a lot of attention but it was just the wrong kind of attention at the wrong time during the very controversial period of that desperate situation of COVID.

What would you tell young adults considering a career in the sciences and specifically the microbiome? What kind of advice would you give them knowing what you’ve gone through in your journey and the challenges and opportunities that exist today?

Pimentel, Mark, M.D.
I would start by saying what my father said, “Try to be better this year than you were last year and always compare yourself to yourself, not to others.” I think as you go through your career if you want to do something, improve what’s there. If you want to make a difference, do something different than anybody expects. I think that is my career, that I wanted to help patients by thinking completely differently, not just following, swimming with the salmon. I wanted to swim upstream because I was seeing things that didn’t match what I was observing in my patients. I knew something was wrong with where the field was going and I turned the corner and it led to some great discoveries. I think that’s true for any industry, any disruptive technology. You can call it disruption when it’s somebody who says what we’re doing isn’t working. This should be better. I think that if you really want to have success, that’s the way.


Dr. Pimentel has spent his career challenging conventional wisdom and persevering even in the face of opposition and criticism. Let’s hope this skill set and experience are enough to overcome the many challenges he and his team face to provide humanity with the breakthrough medical technology that Cedars-Sinai Internal Ultraviolet Therapy represents. Hopefully, we can now separate politics from science and build grassroots support to get the word out on a very promising medical advancement.