After nearly twenty years of working in cosmetic formulation, I rarely describe an ingredient as unique. Most actives perform well only within very specific formulation contexts. Donkey milk, however, consistently stands out.
I first incorporated it into a calming emulsion developed for highly dry and reactive skin. The improvement was not dramatic overnight, but after approximately two weeks of regular use the visible erythema decreased and the skin surface appeared smoother and more comfortable. That observation led me to examine its biochemical composition more carefully.
Donkey milk is often presented as a historical beauty ingredient, yet its relevance is not based on tradition but on composition. Its protein profile, vitamin content and lipid balance are unusually close to human milk. This is what makes it particularly compatible with sensitive skin.
The functional interest in donkey milk comes from the synergy of several components rather than a single active compound.
Analytical data reported in Foods (MDPI) show a significantly higher vitamin C content compared with cow’s milk, in some cases four to five times higher. Vitamin C is essential for collagen synthesis and protection against oxidative stress caused by UV exposure.
It also contains vitamins A and E, along with several B-complex vitamins, which contribute to epidermal renewal and cellular metabolism.
Although donkey milk has a relatively low total lipid content, its fatty acid profile is rich in unsaturated fatty acids, including omega-3 and omega-6. These lipids help support the flexibility of the stratum corneum and improve barrier comfort.
The protein fraction is particularly relevant in cosmetic use. Donkey milk is whey-dominant and contains lysozyme and lactoferrin. Lysozyme exhibits antimicrobial activity, while lactoferrin has documented anti-inflammatory effects in studies referenced in PMC publications. This combination explains its good tolerance in reactive skin.
Minerals such as calcium, magnesium and zinc contribute to enzymatic skin processes, while naturally occurring lactic acid provides mild keratolytic activity, improving skin texture without significant irritation.
Dermatological research also suggests a protective role against UVB-induced damage and partial inhibition of tyrosinase activity, which is associated with a more even skin tone.
skin effects in practiceIn topical use, donkey milk primarily improves skin comfort and hydration balance.
Proteins create a light protective film that helps reduce transepidermal water loss, while the lipid fraction supports barrier lipids. In well-designed emulsions, this translates to longer-lasting hydration and reduced tightness after cleansing.
In mature skin, its antioxidant components help reduce dullness and improve overall appearance rather than acting as a direct anti-wrinkle treatment. The improvement is subtle but consistent.
In individuals with atopic or reactive skin tendencies, I have observed decreased redness after approximately two weeks of daily application of a formulation containing 5% donkey milk powder. In acne-prone skin, lactoferrin appears to support microbial balance without excessive oil removal.
The presence of naturally occurring lactic acid also provides gentle surface renewal, giving the skin a brighter appearance without requiring a separate exfoliating product.
use in formulationFor stability and safety, I work with lyophilized donkey milk powder.
In emulsions, donkey milk can technically be incorporated at levels up to about 8–10% when preservation and emulsion structure are properly designed. In practice, I typically formulate around 5%, which provides measurable skin comfort while maintaining stability and reasonable formulation cost.
For proper incorporation I pre-disperse the lyophilized donkey milk powder in the water phase. I add it under moderate stirring and ensure complete dissolution before emulsification. This step prevents particle formation and uneven distribution within the emulsion.
I avoid prolonged exposure to high temperatures. Short heating during the aqueous phase is acceptable, but I do not keep the system at elevated temperature longer than necessary, as excessive heat can denature part of the protein fraction and reduce its conditioning effect.
After emulsification, I adjust the final pH to approximately 5–6 to maintain compatibility with the skin barrier and support protein stability.
It combines well with humectants such as hyaluronic acid, with barrier lipids or ceramide systems for dry skin and with mild mineral clays in rinse-off masks for balanced cleansing.
Typical applications include moisturizing creams for dry skin, calming serum-emulsions for sensitive skin, soothing masks combined with gentle clays, and lip care formulations where small percentages improve softness.
precautionsHigh percentages may destabilize emulsions due to protein load and can produce a slightly tacky texture. I learned this early when I exceeded the optimal range in a light emulsion.
Patch testing is advisable, particularly for individuals with milk protein sensitivity.
Quality of raw material is critical. I only use microbiologically tested, cosmetic-grade lyophilized powder. Fresh milk is unsuitable for cosmetic stability and preservation.
conclusionDonkey milk should not be viewed as a cosmetic myth or a marketing story. It is a complex biological ingredient whose properties can be explained by its protein, lipid and vitamin composition.
When incorporated thoughtfully into a stable formulation, it improves hydration balance, skin comfort and overall appearance. Its effectiveness is not based on high percentages but on correct formulation strategy.
