Disclosure: this page is published by Vyarna OÜ, which sells a freeze-dried human milk complement. We have tried to state the evidence, including its limits, as a careful reader would want it stated.
Freeze-drying, or lyophilisation, freezes milk and then removes the water by sublimation under vacuum, leaving a powder that can be stored at room temperature and reconstituted with water. It is the same process used for many foods, vaccines and biologics [2]. It is used in two contexts: services that freeze-dry a mother's own expressed milk for her own baby, and products made from donor or provider milk.
A 2024 scoping review in the Journal of Perinatology covered 48 studies of freeze-dried human milk. Its summary: freeze-drying reduces the size of fat globules and the quantity of some enzymes, vitamin C and immunoglobulin; electrolyte disturbances have been reported in preterm infants fed freeze-dried milk; and "due to limited data, further studies exploring the safety and efficacy of FD human milk in preterm infants are needed" [2]. The review also saw promise in freeze-dried human milk as a way to avoid exposing preterm infants to cows'-milk-based fortifiers [2].
A 2022 study in Food Chemistry compared Holder-pasteurised and freeze-dried donor milk with untreated milk and found that the overall changes in protein and volatile-compound profiles were negligible compared with the natural variation between donors [3].
Two cautions in reading this. Most of the data comes from hospital and preterm settings, not from healthy term babies at home. And "reduced" does not mean "absent" — immunoglobulins and enzymes are lowered, not removed, and how much depends on the specific process.
It does not kill bacteria or viruses. Freeze-drying is a preservation step, not a pasteurisation or sterilisation step. Some organisms survive it; some are even preserved by it. This matters because the safety of any freeze-dried milk therefore depends on everything that happened before drying: who the milk came from, what they were screened for, what the milk was tested for, and whether any heat treatment was applied.
Vyarna's own process does not include a validated pathogen-inactivation step. Our safety model rests on provider screening and laboratory testing of the milk — that is, on detection. We say this plainly because it is the first question any informed parent or clinician should ask, and because a supplier who cannot answer it clearly should not be trusted with the question.
The US Food and Drug Administration "does not recommend feeding your baby breast milk acquired directly from individuals or through the Internet", because the donor is unlikely to have been adequately screened for infectious disease or contamination, and recommends that if you use milk from a source other than the baby's mother you "only use milk from a source that has screened its milk donors and taken other precautions to ensure the safety of its milk" [5]. The American Academy of Pediatrics notes that informal milk sharing "may be associated with infectious risks as well as contaminants", and recommends pasteurised donor milk specifically for very low birth weight infants when the mother's own milk is unavailable [1].
Those statements apply to freeze-dried milk exactly as they apply to fresh or frozen milk. The powder form changes storage, not provenance.
Some families use freeze-dried milk — their own or a product — as one component of a mixed diet alongside breastfeeding and formula. It is not a substitute for either. See combining milk sources.
Human milk that has been frozen and then had its water removed under vacuum, leaving a shelf-stable powder that is reconstituted with water. The process is called lyophilisation and is the same one used for many foods and medicines.
It changes some things. A 2024 scoping review of 48 studies found freeze-drying reduces fat-globule size and the quantity of some enzymes, vitamin C and immunoglobulin, while a 2022 study found protein and volatile profiles changed less than the natural variation between donors.
No. Freeze-drying is a preservation method, not a pasteurisation or sterilisation step. Any safety claim for freeze-dried milk has to rest on what was done before drying — donor screening, testing, and any heat treatment — not on the drying itself.
That depends entirely on where the milk came from and how it was screened and tested. The FDA advises against milk from individuals or the internet and recommends only sources that screen donors and take other safety precautions. Ask any supplier exactly what they test for and how.