Cell Based Milk
Industry & regulation

TurtleTree: from cell-based milk to lactoferrin

One of the best-known cell-based milk startups found its first market in a single, high-value milk protein. Its path says a lot about the economics of the field.

Updated 3 min readBy the Cell Based Milk team
Illustration of a milk drop splitting into a single protein molecule

Key takeaways

  • TurtleTree was founded in Singapore in 2019 by Fengru Lin and Max Rye to make milk from mammary cells.
  • Its first commercial product, LF+, is lactoferrin made by precision fermentation, not cell culture.
  • In May 2025, LF+ became the first precision-fermented lactoferrin to receive an FDA 'no questions' letter.
  • The shift reflects a wider pattern: high-value ingredients are easier to make profitable than a commodity like drinking milk.

When this site first covered TurtleTree, it looked like the company most likely to bring cell-based milk to the masses. Its story turned out differently, and in some ways more instructive.

The original vision

TurtleTree was founded in Singapore in 2019 by Fengru Lin, who became CEO, and Max Rye. The goal was ambitious: grow mammary cells in the lab and use them to produce milk and milk components without cows, with an eye on everything from drinking milk to the specialized proteins found in human breast milk.

The company attracted significant investor interest. It raised about $30 million to scale up production of milk ingredients, and in 2021 it opened a 24,000-square-foot R&D facility in the Sacramento area of California to expand its US presence.

The first product: lactoferrin

Rather than launching a carton of milk, TurtleTree zeroed in on one protein: lactoferrin.

Lactoferrin is a protein found in milk that helps regulate iron absorption and supports immune function and gut health. It’s prized in infant formula and supplements, but it’s scarce. Cow’s milk contains only about 100 milligrams per liter, so producing it means processing huge volumes of milk. As a result, it sells for hundreds to thousands of dollars per kilogram, according to FoodNavigator.

In 2022, TurtleTree unveiled LF+, a bovine lactoferrin made using precision fermentation: microbes engineered to produce the protein, rather than mammary cells. (Not sure of the difference? See cell-based milk vs. precision fermentation.)

Milestones

  • 2019: Founded in Singapore by Fengru Lin and Max Rye
  • 2021: Opened an R&D facility in the Sacramento area of California
  • 2022: Unveiled LF+, a precision-fermented bovine lactoferrin
  • 2023: LF+ achieved self-affirmed GRAS status and Vegan Action certification
  • May 2025: Received an FDA “no questions” letter for LF+, the first for a precision-fermented lactoferrin

TurtleTree has since supplied LF+ to manufacturers and used it in its own nutrition products.

Why the shift makes sense

TurtleTree’s path reflects the basic economics of the field.

Milk is cheap. Lactoferrin isn’t. Conventional milk is a commodity sold at low margins. A protein worth hundreds or thousands of dollars per kilogram leaves far more room to cover the cost of new technology.

Microbes are easier to scale. Precision fermentation uses existing fermentation infrastructure, and microbes grow quickly on inexpensive feedstocks. Mammalian cell culture is slower and depends on costly growth media.

A clearer regulatory path. A single, purified protein can go through the GRAS process. A whole cell-cultured milk raises more complex questions about safety and labeling.

What it means for cell-based milk

TurtleTree’s move doesn’t mean cell-based milk has failed. Companies such as Opalia and Brown Foods are still pursuing whole cell-cultured milk, and both are moving toward pilots and regulatory filings. See our company tracker.

But it does suggest a likely pattern: high-value ingredients first, everyday milk later. Early cell-based dairy may reach you inside cheese, infant formula or supplements long before it reaches the milk aisle.

Sources

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