Paris health startup Lucis raises $20M Series A months after seed

A Parisian preventive-health startup, Lucis, has secured a $20 million Series A funding round led by Singular, with additional participation from General Catalyst, Y Combinator, and a group of angel investors including Céline Lazorthes of Resilience, Manu Lecomte, and backers of the running-coach app Runna. This investment arrives just four months after the company’s $8.5 million seed round in December 2025, pushing its total funding to approximately $28 million.

Lucis will use the capital to fuel expansion into Spain, Germany, and Italy by the end of 2026, alongside further development of the AI layer that transforms biomarker data into ongoing health guidance. The company has not disclosed its valuation.

Founded in 2025 by Maxime Berthelot, Baptiste Debever, and Max Guérois, Lucis is a product of Y Combinator’s 2025 batch. Its model is straightforward and increasingly common: members receive a blood draw at a partner laboratory, and the platform analyzes over 110 biomarkers spanning metabolic, hormonal, cardiovascular, inflammatory, and nutritional systems. The results then feed an AI companion that recommends changes in nutrition, supplementation, lifestyle, and follow-up testing, all under physician oversight. As new data comes in, the recommendations refine. Lab partners include Eurofins and Randox.

This pitch lands on familiar ground. A growing number of US and European startups such as Function Health, Superpower, Forward, and Berlin’s HealthCaters are betting that consumers will pay out of pocket to monitor their own biomarkers before any clinical reason arises. Lucis differentiates itself less by the underlying tests, which are commodity work from certified labs, and more by its AI layer and the promise of longitudinal tracking. The company claims that among users who completed a six-month follow-up, 75% improved at least three biomarkers without medication, and more than 80% chose to retest.

These figures are company-supplied and have not been independently audited. The same goes for Lucis’s more striking claim: that 99.9% of users had at least one biomarker outside optimal ranges at first test. The implied claim, that almost everyone has something subclinical happening, is exactly what a company selling subclinical testing would say.

The Series A pitch rests partly on whether sustained engagement and measurable biomarker improvement translate into the long-term retention that preventive-health platforms have historically struggled to demonstrate. The macroeconomic case is sturdier. The World Health Organisation’s June 2025 European report attributes 1.8 million avoidable deaths a year across the WHO European Region to non-communicable diseases, at an economic cost of $514 billion, with the agency arguing that 60% of those deaths could be prevented through risk-factor reduction. Lucis cites that figure as the gap its product is built to address.

“Europe’s preventive health category will be won by platforms that unite clinical credibility with AI at scale,” said Jeremy Uzan, co-founder and general partner at Singular, in a statement. He pointed to Lucis’s pace of user growth, reaching 10,000 in under a year, as evidence the category is ready to consolidate.

The Series A puts Lucis at a similar scale to other recent European AI-health raises, including the $20 million round closed by Blossom Health for AI copilots in psychiatry. Whether preventive testing is a durable consumer category or a wellness adjacent to one is the open question. Lucis says expansion across the rest of the EU will follow over the next 12 months.