What does Lactase do?

Digestive enzyme that breaks down lactose. Clinically shown to reduce symptoms of lactose intolerance in infants and adults.

Lactase supplements are often used without a proper diagnosis — many people self-diagnose lactose intolerance when they may have IBS, milk protein allergy, or another condition entirely

Lactase - Science-Based Research

What the Science Says

Lactase is a naturally occurring digestive enzyme that breaks down lactose — the sugar found in milk and dairy products. People whose bodies don't produce enough lactase experience bloating, gas, and diarrhea after consuming dairy; taking supplemental lactase before meals can reduce or prevent these symptoms. Clinical trials in infants and preterm newborns show it significantly reduces crying, vomiting, and gastrointestinal distress caused by lactose intolerance, with effects seen within the first week of use.

What It Doesn't Do

Won't cure lactose intolerance permanently — it only works when taken with dairy. Not a treatment for milk protein allergy, which is a completely different condition. Doesn't help people who are lactose-tolerant — no benefit if your body already makes enough lactase. Won't reduce inflammation markers like CRP or calprotectin based on available evidence. Not a probiotic and doesn't change your gut microbiome.

Evidence-Based Benefits

Lactase is a naturally occurring digestive enzyme that breaks down lactose — the sugar found in milk and dairy products. People whose bodies don't produce enough lactase experience bloating, gas, and diarrhea after consuming dairy; taking supplemental lactase before meals can reduce or prevent these symptoms. Clinical trials in infants and preterm newborns show it significantly reduces crying, vomiting, and gastrointestinal distress caused by lactose intolerance, with effects seen within the first week of use.

Moderate Evidence

Effective at: 180–600 FCC units per feeding (drops or tablet form); No single universal dose established

Source: auto-research

Absorption & Bioavailability

Unknown for systemic absorption — lactase works locally in the gut to break down lactose before it reaches the colon. A key challenge is enzyme degradation in stomach acid; newer pH-responsive tablet formulations aim to protect the enzyme until it reaches the small intestine, achieving ~94% enzyme activity recovery and near-complete release at intestinal pH.

Red Flags to Watch For

Lactase supplements are often used without a proper diagnosis — many people self-diagnose lactose intolerance when they may have IBS, milk protein allergy, or another condition entirely
Standard liquid drop formulations may lose enzyme activity in stomach acid before reaching the small intestine where lactose is digested
Avoiding dairy entirely without medical guidance can lead to calcium and vitamin D deficiencies — lactase supplementation is preferable to unnecessary dairy elimination
Some products used as 'placebo' in drug trials (like methylphenidate studies) are labeled as lactase — this does not mean lactase has cognitive effects; it was simply an inert control