Sun Spot: The90 Debuts a Personal UV Exposure Wearable

The90 has launched its smart jewelry wearable, The90 Gem, a product designed to help women understand and manage their real-time sun exposure, protect long-term skin health, and build a smarter relationship with the sun.

The90 was built around the reality that up to 90% of visible skin aging and premature skin damage is linked to cumulative, everyday UV exposure that—until now—consumers have been unable to measure in real time.

As the first reported personal sun intelligence system, The Gem and its companion The90 app track real-time UVA and UVB exposure and translate that data into personalized guidance. UVA rays are associated with long-term skin aging and can penetrate through windows, while UVB rays are more closely tied to sunburn, making both important to understand when managing daily sun exposure. By combining live UV measurement with each user’s skin profile, sunscreen use, and protective clothing, The90 helps women move beyond generic UV estimates and make more informed decisions about sun exposure, sunscreen timing, and healthy skin aging, according to the company. 

Key features of The90’s technology include:

• Real-time UVA and UVB tracking: Measures UV exposure using live sensor data in The90 Gem to reflect the user’s experience throughout the day, from walking outside to sitting near a sunny window.
• Personalized skin profile: Allows users to create a unique skin profile in the app by logging their skin type, daily sunscreen use, and sun-protective behaviors.
• Smart sun intelligence: Turns real-time UV data into actionable guidance, including personalized UV thresholds, sunscreen reapplication reminders, and smarter sunlight exposure windows based on real-time conditions and individual skin needs.
• Modular smart jewelry design: Designed as a high-end pendant necklace, The90 Gem brings UV tracking into a jewelry form factor users can style and wear throughout the day.

The company is backed by strategic investors including Chase Fisher, founder of Blenders Eyewear; Alex Haro, founder of Life360 and Hubble; Steven Borelli, founder of Cuts Clothing; SpaceStation Investments; and Lauryn Bosstick, entrepreneur, podcast host, and founder of The Skinny Confidential, who is also joining The90 as an advisor.

“I’ve always believed skincare is about the little daily habits that add up over time,” said Bosstick. “Women are already investing in SPF, treatments, tools, and routines to protect their skin, but when it comes to sun exposure, most of us are still guessing. The UV Index on your phone doesn’t know your skin, your sunscreen, or the small moments of exposure that happen throughout the day. The90 gives women the missing data to make smarter decisions and stay ahead of skin aging before it starts.”

The90 was founded by CEO Stacy Salvi, a healthtech pioneer who spent more than a decade in wearables; she led the business relationship that culminated in Google’s $2.1 billion Fitbit acquisition. As the daughter of a dermatologist and a visionary who most recently helped build a smart ring for women, Salvi founded The90 to empower women with real-time, personal data about sun exposure, an important but not well-understood driver of long-term skin health.

“True innovation happens when deep technology is wrapped in a high-end, modular aesthetic that women actually want to wear,” Salvi stated. “We are on the cusp of a skincare revolution. The90 transforms sunscreen from a one-time morning ritual into an adaptive, responsive system built around your actual UV load. We want to empower women to stop guessing and finally own their light, strategically harnessing the sun for optimal health.”

The90 is the first personal sun intelligence system designed to help women decode their real-time UVA and UVB exposure and take control of their aging. The90 Gem is a preventative skin health wearable that measures UV exposure as an individual’s skin experiences it, replacing generic zip code estimates with personalized data. Paired with the The90 app, available on Apple and Android app stores, the system tracks cumulative sun exposure, models sunscreen decay, and delivers personalized reapplication prompts based on actual UV load. The90 is rooted in the fact that up to 90% of visible skin aging— including wrinkles, fine lines, and sun spots—is caused by UV exposure rather than chronological aging.