Paris-based preventive health startup Lucis secures $20 million in Series A funding just four months after its seed round.

      Lucis, a preventive health platform based in Paris that combines blood biomarker testing with an AI-driven companion app, has secured $20 million in a Series A funding round led by Singular, with participation from General Catalyst, Y Combinator, and angel investors such as Céline Lazorthes of Resilience, Manu Lecomte, and supporters of the running-coach app Runna. This funding round comes four months after the company raised $8.5 million in seed funding in December 2025, bringing its total funding to approximately $28 million. Lucis plans to use this capital to expand into Spain, Germany, and Italy by the end of 2026, as well as to continue developing its AI capabilities that provide ongoing health guidance based on biomarker data. The company has not disclosed its valuation.

      Founded in 2025 by Maxime Berthelot, Baptiste Debever, and Max Guérois, Lucis participated in Y Combinator’s 2025 batch. Its business model is straightforward: members undergo blood draws at partnered laboratories, where the platform analyzes over 110 biomarkers related to metabolic, hormonal, cardiovascular, inflammatory, and nutritional systems. The results then inform an AI companion that suggests changes in nutrition, supplementation, lifestyle, and follow-up testing under the supervision of a physician. Recommendations are updated with new data. Their lab partners include Eurofins and Randox.

      The concept fits within a larger trend, as an increasing number of US and European startups, such as Function Health, Superpower, Forward, and Berlin’s HealthCaters, are banking on consumers being willing to pay for personal biomarker monitoring even before any clinical necessity arises. Lucis distinguishes itself less by the tests themselves, which are standard procedures conducted by certified labs, and more by the AI component and the promise of longitudinal tracking: it claims that 75% of users who completed a six-month follow-up saw improvements in at least three biomarkers without medication, and over 80% opted to retest.

      These figures, supplied by the company, have not been independently verified. Lucis also highlights that 99.9% of users had at least one biomarker outside optimal ranges during their initial test. The implicit assertion that nearly everyone experiences some subclinical issue aligns with the claims of a company offering subclinical testing.

      The success of the Series A funding pitch hinges, in part, on whether sustained engagement and noticeable biomarker improvements can lead to the long-term retention that preventive health platforms have historically found challenging to demonstrate.

      The macroeconomic rationale is stronger, as the World Health Organization’s June 2025 European report attributes 1.8 million avoidable deaths annually in the WHO European Region to non-communicable diseases, costing the economy $514 billion. The organization claims that 60% of these deaths could be prevented through risk-factor reduction, which Lucis cites as the gap its product intends to address.

      “Platforms that combine clinical credibility with AI at scale will lead the preventive health sector in Europe,” said Jeremy Uzan, co-founder and general partner at Singular, noting Lucis's rapid user growth to 10,000 in less than a year as evidence of the readiness for consolidation in this category.

      The Series A funding positions Lucis similarly to other recent European AI health funding rounds, such as Blossom Health’s $20 million for AI copilots in psychiatry. The central question remains whether preventive testing is a sustainable consumer category or merely a wellness trend. Lucis states it plans to expand throughout the rest of the EU in the following 12 months.