Prysm iO vs Veggie Meter: skin carotenoid scanners compared

Short answer

Both measure carotenoid antioxidants in the skin through the fingertip. The Veggie Meter, from Longevity Link Corporation, uses pressure mediated reflection spectroscopy and is widely used in nutrition research. Prysm iO, from Nu Skin, uses hyperspectral absorption with an AI algorithm and is designed for consumers and clinics, with an app and personalised feedback.

Side by side

	Prysm iO	Veggie Meter
Maker	Nu Skin (Provo, Utah)	Longevity Link Corporation (Utah)
Method	Hyperspectral absorption (Spectral Rai) plus AI algorithm	Pressure mediated reflection spectroscopy
Scan site	Fingertip	Fingertip, with gentle pressure from a small arm
Scan time	About 15 seconds	A short fingertip scan
Output	Prysm Score, colour zone and app feedback	Skin carotenoid score
Form	Small, circular, portable	Benchtop unit
Main users	Consumers, clinics, practitioners	Researchers, schools, nutrition programmes
Research	Nu Skin studies and registered trials; strong link to blood carotenoids	Many independent validation studies
Where to get it	Nu Skin brand affiliates	Longevity Link

How the technology differs

Veggie Meter. White LED light is reflected off the fingertip while a small arm presses gently on the finger. The pressure pushes blood out of the tissue so haemoglobin interferes less with the carotenoid signal. Published work reports a correlation of about r = 0.81 with blood plasma carotenoids and close agreement with older Raman scanners.

Prysm iO. The fingertip rests on the lens and the device captures more than 70,000 hyperspectral absorption measurements in one scan. An AI model trained on Nu Skin's database of more than 20 million scans converts them into the Prysm Score. Nu Skin reports a strong correlation with blood carotenoid levels.

Which should you choose?

Running a nutrition study? The Veggie Meter's body of independent research makes it the established research tool.
Scanning clients in a clinic or tracking yourself? Prysm iO is portable, fast, connects to an app and comes with a programme for improving the score.

Common questions

Is Prysm iO better than the Veggie Meter?

They suit different users. The Veggie Meter has a long track record in independent nutrition research. Prysm iO is built for consumers and clinics, with a portable design, an app, personalised feedback and a supplement programme. If you are running a research study, the Veggie Meter's published literature is a strength. If you want to scan clients and track them over time, Prysm iO is designed for that.

Can I compare a Veggie Meter score with a Prysm Score?

Not directly. The two devices use different methods and scales. Track your progress on one device.

Do both devices measure the same thing?

Yes, both estimate carotenoid levels in the skin, which reflect fruit and vegetable intake and carotenoid supplementation.