What Is Known About Prysm iO and Skin Carotenoid Scanning

Yale School of Public Health: A Review of the Method

Reading skin carotenoid levels with light as a marker linked to fruit and vegetable intake was studied over many years by academic groups, including a team led by Dr. Susan T. Mayne at the Yale School of Public Health, working with physicists at the University of Utah who built early scanning instruments. One reason researchers liked the approach was practical: a quick skin reading avoids drawing blood in large community studies, including studies of children.

In a 2013 review, the Yale team brought together their own studies, among them a survey of 1,375 adults and a study of 381 children, with the wider literature. They described skin carotenoid status as a promising biomarker for human research that could be measured consistently and in field settings. They also noted that diet explains only part of the variation seen between people and that larger studies were still needed.

Source: Mayne ST, Cartmel B, Scarmo S, Jahns L, Ermakov IV, Gellermann W. Resonance Raman spectroscopic evaluation of skin carotenoids as a biomarker of carotenoid status for human studies. Arch Biochem Biophys. 2013;539(2):163-70. PubMed

That body of work is about research use. It is the foundation that later scanners, including Prysm iO, build on, and it is not a statement about any individual customer's health.

Comparing the Fingertip Reading With a Blood Measure

Nu Skin reports a comparison study, run with dermatologist Dr. Zoe Draelos, that set Prysm iO's 15-second fingertip reading beside a laboratory measure of carotenoids in blood across 97 participants. The two moved together to a degree that the paper describes with a correlation figure.

Any measurement carries some variation, and Nu Skin cites roughly ±10% in typical field use. Treat one reading as a snapshot. The pattern across repeated scans over time is the more useful thing to talk about with a customer.

Company-Reported Studies and Ongoing Work

Nu Skin has also reported a lifestyle study at Shanghai Jiao Tong University in which 589 healthy adults were scanned with Prysm iO and compared with their own reports of what they ate and how they lived. Higher scores went along with reporting more fruit, vegetables and whole grains, and more regular exercise and sleep. That kind of finding shows association only. It does not show that anything causes anything else.

This is company-reported, correlational data based on self-reported information, and it has not been independently published in a peer-reviewed paper. It is supporting background rather than the same standard of evidence as the Yale review above.

Nu Skin has also said that further studies with university partners are in progress. Until results are published, this site does not describe them.

Recognition From Outside Nu Skin

Since launch, Prysm iO has received design and innovation recognition. These awards speak to the product and its design, not to any health outcome:

• Achievement in Technology Innovation - TITAN Business Awards (winner page)
• Best of Category, Wellness Insight - Globee Business Awards
• Personal category winner - Good Design Awards 2025 (project page)

Prysm Certified Products and the Score Guarantee

Nu Skin labels some Pharmanex products “Prysm Certified”, meaning its own scientists formulated them with a view to raising a customer's Prysm score over time. Alongside that, Nu Skin offers a money-back guarantee if the score has not improved after 90-100 days on a certified, Prysm-eligible product, subject to Nu Skin's Terms and Conditions. Reading the terms for your market before you mention it to anyone is wise, and so is remembering that these are supplements, not medicines.

Two Decades of Development

Prysm iO is the fourth generation of a scanner family that began in 1999 with the Pharmanex BioPhotonic Scanner, a room-sized machine that needed about an hour to calibrate. Smaller, portable versions followed, using Raman spectroscopy, a technique named after physicist C.V. Raman. The S1 launched commercially in 2003, the S2 in 2006 and the S3 in 2013, and together those devices reached 51 countries and more than 25 million scans.

Prysm iO is a new generation rather than a repackaged S3. It reads from a fingertip instead of the palm and uses a different underlying method, which Nu Skin calls patent-pending “spectral ray” technology, working from hundreds of thousands of light measurements per scan. Its AI-driven scoring still refers back to the earlier Raman research. What carries over is more than 20 years of research and the data from those 25 million scans.