Longevity startup Retro Biosciences reaches $1.8 billion valuation in latest funding round
US-based biotech startup Retro Biosciences has announced that it has raised $180 million in its latest funding round and that the company's valuation has reached $1.8 billion. This is the company's third and largest funding round since its founding in 2021.
Retro Biosciences was originally financed by OpenAI Chief Sam Altman with $180 million in initial funding from his personal capital. Investors in the latest round include Khosla Ventures, Founders Fund and Andreessen Horowitz's biotech arm a16z Bio. Documents obtained by STAT News indicate that Altman also increased his stake with an additional $30 million contribution.
The company's primary research direction is built around cellular rejuvenation technologies. Chief Scientific Officer Joe Betts-LaCroix told STAT: 'Our objective is to extend human healthspan by a decade; this is not an ordinary drug but pharmacological intervention targeting the biological aging process.'
Retro Biosciences's primary research platform involves testing modified versions of the Yamanaka factors — the stem-cell reprogramming proteins discovered in 2006 by Nobel laureate Shinya Yamanaka — in human cells. The company argues that this approach can reverse the biological age of cells.
On the clinical trial front, the company has not yet started FDA-approved clinical trials for any of its products. The company's road map includes initiating its first Phase 1 clinical trial in 2027. Sector analysts say they consider this timeline optimistic.
Competition in the longevity sector is intensifying. Altos Labs, backed by Jeff Bezos and Yuri Milner, was founded in 2022 with $3 billion in initial financing and operates research laboratories in Cambridge, San Francisco and San Diego. Calico, Google's longevity research company founded in 2013, runs a $2.5 billion partnership with pharma firm AbbVie.
The longevity sector's position within the scientific community remains debated. Albert Einstein College of Medicine Professor of Gerontology Dr Nir Barzilai, in an independent assessment to STAT, said: 'There is significant progress scientifically in understanding the biochemical mechanisms of aging; but the challenges of translation to practice, and the clinical efficacy evidence, remain in early stages.'
The financing community's assessment is also mixed. Wedbush Securities biotech analyst David Nierengarten said: 'The anti-aging drug market is potentially large, but the FDA not recognising aging as an indication forces companies in this sector to focus on specific disease indications. Retro Biosciences's strategy is not yet clear.'
Retro Biosciences's most recent research publication appeared in the journal Cell in February 2026. The study showed that a modified version of the Yamanaka factors reversed cellular epigenetic age by approximately 18 per cent in a mouse model under a specific treatment regime. External independent researchers plan to verify this result in the coming months.
The company has announced that the funds raised from the latest round will be spent on expanding the main laboratory (at its San Francisco headquarters), research-personnel hiring and preclinical studies. This article is general information; for biotech investment or treatment-choice decisions, independent financial and medical advice is recommended.