Last verified: 17 days ago
Alpha-Lactalbumin
Also known as: α-lactalbumin, α-lac, ALAC, alpha-lac, whey protein fraction
Evidence under review. — Not yet rated
Whey protein fraction found in breast milk. Limited evidence for immune or sleep benefits in adults.
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What it does
Alpha-lactalbumin is a small whey protein naturally found in human breast milk and cow's milk. It plays a role in lactose synthesis and is a source of essential amino acids. Research in infants...
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Evidence quality
Evidence base hasn't been formally rated yet. See research below.
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Clinical dose
No established dose
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Found in
What the Science Says
Alpha-lactalbumin is a small whey protein naturally found in human breast milk and cow's milk. It plays a role in lactose synthesis and is a source of essential amino acids. Research in infants suggests it may support gut health and immune development when used in enriched formulas, though benefits over standard formula appear modest. In adults, it has been explored for sleep support and bone health, but evidence remains preliminary.
What It Doesn't Do
Not proven to improve sleep in athletes or people with sleep difficulties. No strong evidence it boosts immunity in adults. Not a proven bone-density treatment on its own. Don't confuse it with general whey protein — it's one specific fraction with limited standalone research.
Evidence-Based Benefits
Alpha-lactalbumin-enriched infant formulas support normal infant growth comparable to standard formulas.
Moderate EvidenceEffective at: Enriched whey fraction in infant formula (27% α-lac of whey protein)
Supporting studies (click to view on PubMed):
May reduce intestinal inflammation and support gut barrier function in young animal models.
Weak EvidenceEffective at: No established dose
Supporting studies (click to view on PubMed):
Pre-sleep alpha-lactalbumin supplementation does not improve sleep or athletic performance in people with sleep difficulties.
Weak EvidenceEffective at: No data from provided studies
Supporting studies (click to view on PubMed):
Absorption & Bioavailability
Unknown — no pharmacokinetic or absorption data provided in the supplied studies. As a whey protein fraction, it is generally considered digestible, but specific bioavailability data for supplemental alpha-lactalbumin is not reported.
Red Flags to Watch For
- People with cow's milk allergy should avoid it — alpha-lactalbumin is a known milk allergen and has been identified as a component in some MMR vaccines that triggered allergic reactions
- PFDA (a common environmental contaminant found in food packaging) has been shown to structurally disrupt alpha-lactalbumin and impair its calcium-binding function — relevant for formula-fed infants
- Most clinical evidence comes from infant formula studies, not adult supplementation — adult dosing and benefits are largely unestablished
- Case series on bone health used only 6 patients over 2 months with no control group — extremely preliminary data
Products Containing Alpha-Lactalbumin
See how Alpha-Lactalbumin is used in these analyzed products:
Frequently Asked Questions
What does Alpha-Lactalbumin do?
Whey protein fraction found in breast milk. Limited evidence for immune or sleep benefits in adults.
What is the effective dose of Alpha-Lactalbumin?
No established dose
Is Alpha-Lactalbumin safe?
People with cow's milk allergy should avoid it — alpha-lactalbumin is a known milk allergen and has been identified as a component in some MMR vaccines that triggered allergic reactions
What doesn't Alpha-Lactalbumin do?
Not proven to improve sleep in athletes or people with sleep difficulties.
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-05-25