Lucis is a Paris-based preventive-health startup, part of Y Combinator's 2025 batch, building an AI-driven platform that gives people a comprehensive, data-backed view of their health. It analyzes more than 110 blood biomarkers across key systems such as metabolic health, hormones, cardiovascular risk, inflammation, and nutrient levels, then translates results into clear scores and personalized guidance. Since launching in 2025, Lucis has grown to over 10,000 users across France, the UK, Ireland, and Portugal and delivered more than one million biomarker tests. In May 2026 it raised a $20M (€17.3M) Series A led by Singular, with General Catalyst, Y Combinator, and angels participating, just months after an $8M seed. Lucis aims to make preventive health a standard across Europe.