The Research Behind the Prysm iO Reading

Yale School of Public Health: Where the Method Was Refined

The scanning method behind Prysm iO - reading skin carotenoid levels as a proxy for nutritional status - was developed over more than a decade of published research, much of it led by Dr. Susan T. Mayne's team at the Yale School of Public Health and Yale Cancer Center, working alongside physicists at the University of Utah who built the original scanning instruments.

Notably, the Yale team turned to this non-invasive scanning method specifically because their researchers were reluctant to send graduate students into the field to draw blood from children for a study on inner-city kids' nutritional status - a non-invasive scan solved a genuine practical problem, not just a marketing one.

Their 2013 review in Archives of Biochemistry and Biophysics drew together their own studies (including a 1,375-person adult survey and a 381-child study) alongside the wider published literature. Its authors wrote that:

“Skin carotenoid status as assessed by RRS is an attractive biomarker for use in human studies.”

- 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

The same paper also explains why a measurement can add something that food diaries cannot:

“Without objective verification that behavior change has occurred, results of trials [...] are difficult to interpret.”

- Same source (PubMed), on the limits of relying on self-reported diet alone in research.

In short, the authors treated skin carotenoid status as a biomarker of fruit and vegetable intake that shifts with supplementation and dietary change, and that may also mirror wider wellness. They were just as open that diet explains only part of the variation seen and that larger studies were still required. Later scanners, Prysm iO among them, build on that measured foundation.

Compared With a Blood Measure of the Same Pigments

A specialized blood test for serum carotenoids - not a routine part of standard bloodwork, and typically a 3-week wait at a specialist lab - is the recognized laboratory way to measure this biomarker. Nu Skin ran a study, with dermatologist Dr. Zoe Draelos, that set Prysm iO's 15-second skin reading beside that blood test in 97 participants.

Like any measurement device, Prysm iO carries a margin of error - Nu Skin cites roughly ±10% in typical field use. A single reading should be treated as a snapshot; the trend across repeated scans over time is the more meaningful signal.

A Lifestyle Study Outside the Lab

Nu Skin has also reported a study conducted at Shanghai Jiao Tong University, scanning 589 healthy adults with Prysm iO and comparing scores against self-reported diet, lifestyle, fitness, sleep, and skin health. Higher scores were associated with eating more fruit, vegetables, whole grains, and freshwater fish, a balanced BMI, prioritizing sleep, regular exercise, and limiting UV exposure - alongside better self-reported skin smoothness, hydration, and tone, and fewer digestive or cold/flu symptoms. Lower scores were associated with more fried food, sugary drinks, and red meat.

These are correlations reported by Nu Skin and based on self-reported diet and outcomes. They are not from an independently published, peer-reviewed paper, so they are supporting information and carry less weight than the Yale biomarker research above.

Source: Nu Skin research bulletin on correlations between skin carotenoid score and diet, lifestyle and skin attributes (NSE Products, 2026), principal investigator Professor Cai of Jiao Tong University. Read the bulletin (PDF). The bulletin also reports a correlation of 0.806 between Prysm iO and BioPhotonic Scanner S3 scores in the same 589 people.

Recognition From Outside Nu Skin

Since launch, Prysm iO has also picked up recognition from outside Nu Skin's own research program:

• 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 certifies certain products as “Prysm Certified” - meaning their own scientists believe those products are formulated to help raise a patient's Prysm Score over time. Nu Skin also offers a money-back guarantee on certified, Prysm-eligible products, subject to Nu Skin's Terms and Conditions. A score is a wellness reading influenced by many things, so please do not present it to patients as evidence that a product is, or is not, working.

Twenty Years of Development

Prysm iO is the fourth generation of a scanning lineage that began in 1999 with Pharmanex's first Biophotonic Scanner - room-sized, taking around an hour to calibrate, but the first device to measure antioxidants non-invasively through the skin. A smaller, portable version followed in 2002, using Raman spectroscopy (a technique dating back roughly a century to physicist C.V. Raman). The S1 launched commercially in 2003, the S2 in 2006, and the S3 in 2013 - Bluetooth-enabled, with 30-second scans, eventually reaching 51 countries and over 25 million scans worldwide.

Prysm iO is a genuinely new generation rather than a repackaged S3: it scans from a fingertip instead of the palm, and uses a different underlying method - patent-pending “spectral ray” technology, reading how skin absorbs and reflects hundreds of thousands of light measurements per scan (the same basic principle as a pulse oximeter), rather than the emitted-signal approach Raman spectroscopy relies on. Its AI-driven scoring algorithm still references the underlying Raman research base, but the 30-second scan time and Raman method themselves belong to the S3 generation, not to Prysm iO specifically. What carries over is the more than 20 years of R&D and over 25 million scans' worth of data that Nu Skin's research draws on.