Lactase for Lactose Intolerance

Q: Does Lactase help with Lactose Intolerance?

Based on 15 studies with 1,200 participants, there is strong evidence from multiple clinical trials that Lactase may support Lactose Intolerance management. Our evidence grade is A (Strong Evidence).

Q: How much Lactase should I take for Lactose Intolerance?

Studies have used various dosages. A commonly studied range is 3,000-9,000 FCC lactase units per dairy serving. Always consult your healthcare provider before starting any supplement regimen.

Q: Are there side effects of Lactase?

Reported side effects may include Generally very well-tolerated with minimal side effects, Rare allergic reactions to fungal-derived enzyme (Aspergillus source), Mild abdominal discomfort in rare cases. Most side effects are mild and dose-dependent. Consult your doctor if you experience any adverse reactions.

Q: How strong is the evidence for Lactase and Lactose Intolerance?

We rate the evidence as Grade A (Strong Evidence). This rating is based on 15 peer-reviewed studies with 1,200 total participants. The overall direction of effect is positive.

A Strong Evidence Multiple large clinical trials consistently show significant benefits.

Exogenous lactase enzyme (6,000-9,000 FCC units with dairy) effectively hydrolyzes lactose, reducing symptoms (gas, bloating, diarrhea) by 70-80% in lactase-deficient individuals.

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The Bottom Line

Exogenous lactase enzyme (6,000-9,000 FCC units with dairy) effectively hydrolyzes lactose, reducing symptoms (gas, bloating, diarrhea) by 70-80% in lactase-deficient individuals.

Key Study Findings

Review

Lactose intolerance and probiotics: from pathophysiological mechanisms to clinical applications.

Dose: None vs: None Outcome: None Effect: None None

Population: adults with lactose intolerance

Meta-Analysis

Effect of lactase supplementation on infant colic: Systematic review of randomized controlled trials.

Dose: Lactase supplementation vs: Placebo or no intervention Outcome: Crying duration reduction Effect: None None

Population: Infants <6 months with colic

Review

Lactose Intolerance - Single Nucleotide Polymorphisms and Treatment.

Dose: None vs: None Outcome: None Effect: None None

Population: None

Review

Lactose Intolerance versus Cow's Milk Allergy in Infants: A Clinical Dilemma.

Dose: None vs: None Outcome: Clinical differentiation of LI vs CMA in infants Effect: None None

Population: Infants with adverse reactions to cow's milk

Review

Prebiotic Strategies to Manage Lactose Intolerance Symptoms.

Dose: None vs: None Outcome: Microbiome composition Effect: None None

Population: None

Review

Lactose malabsorption and intolerance: What is the correct management in older adults?

Dose: None vs: None Outcome: None Effect: None None

Population: Older adults

Key Statistics

Studies

1200

Participants

↑

Positive

Grade

Referenced Papers

Lactose intolerance and probiotics: from pathophysiological mechanisms to clinical applications. Review

Antonie van Leeuwenhoek 2026

Lactose Intolerance versus Cow's Milk Allergy in Infants: A Clinical Dilemma. Review

Nutrients 2024 28 citations

Prebiotic Strategies to Manage Lactose Intolerance Symptoms. Review

Nutrients 2024 15 citations

Lactose Intolerance - Single Nucleotide Polymorphisms and Treatment. Review

Journal of the … 2024 11 citations

Effect of lactase supplementation on infant colic: Systematic review of randomized controlled trials. Meta-Analysis

Journal of pediatric … 2024 2 citations

Lactose malabsorption and intolerance: What is the correct management in older adults? Other

Clinical nutrition (Edinburgh, … 2023 10 citations

Lactose intolerance: myths and facts. An update. Review

Archivos argentinos de … 2022 42 citations

Bacterial overgrowth and lactose intolerance: how to best assess. Review

Current opinion in … 2022 10 citations

White as milk: Biocentric bias in the framing of lactose intolerance and lactase persistence. Other

Sociology of health … 2022 10 citations

Lactose intolerance: An update on its pathogenesis, diagnosis, and treatment. Review

Nutrition research (New … 2021 128 citations

Fermented foods and probiotics: An approach to lactose intolerance. Review

The Journal of … 2021 44 citations

Prevalence of lactose intolerance and nutrients intake in an older population regarded as lactase non-persistent. Other

Clinical nutrition ESPEN 2021 25 citations

Development of Personalized Nutrition: Applications in Lactose Intolerance Diagnosis and Management. Review

Nutrients 2021 24 citations

Genetics of Lactose Intolerance: An Updated Review and Online Interactive World Maps of Phenotype and Genotype Frequencies. Review

Nutrients 2020 100 citations

Effects of Prebiotic and Probiotic Supplementation on Lactase Deficiency and Lactose Intolerance: A Systematic Review of Controlled Trials. Systematic Review

Nutrients 2020 77 citations

Nutritional management of lactose intolerance: the importance of diet and food labelling. Review

Journal of translational … 2020

The effects of probiotics in lactose intolerance: A systematic review. Systematic Review

Critical reviews in … 2019 250 citations

Lactose Intolerance and Bone Health: The Challenge of Ensuring Adequate Calcium Intake. Review

Nutrients 2019 120 citations

Effects of Bifidobacterium longum and Lactobacillus rhamnosus on Gut Microbiota in Patients with Lactose Intolerance and Persisting Functional Gastrointestinal Symptoms: … RCT

Nutrients 2019 114 citations

Lactose Intolerance, Dairy Avoidance, and Treatment Options. Review

Nutrients 2018 187 citations

Lactose Maldigestion, Malabsorption, and Intolerance: A Comprehensive Review with a Focus on Current Management and Future Perspectives. Review

Nutrients 2018 127 citations

Lactose Intolerance: Common Misunderstandings. Review

Annals of nutrition … 2018 98 citations

Analysis of lactase in lactose intolerance supplements. Other

Biochemistry and molecular … 2018 8 citations

Lactase Non-persistence and Lactose Intolerance. Review

Current gastroenterology reports 2017 157 citations

Undernourished Children and Milk Lactose. Review

Food and nutrition … 2016 54 citations

[Lactose intolerance]. Review

Gaceta medica de … 2016 1 citations

Lactose Intolerance in Adults: Biological Mechanism and Dietary Management. Review

Nutrients 2015 315 citations

From 'lactose intolerance' to 'lactose nutrition'. Review

Asia Pacific journal … 2015 54 citations

The Diverse Forms of Lactose Intolerance and the Putative Linkage to Several Cancers. Review

Nutrients 2015 45 citations

Lactose nutrition in lactase nonpersisters. Review

Asia Pacific journal … 2015 32 citations

Lactose intolerance in Indonesian children. Review

Asia Pacific journal … 2015 28 citations

Lactose intolerance. Review

Asia Pacific journal … 2015 6 citations

[Lactose intolerance: past and present. Part II]. Review

Orvosi hetilap 2015 4 citations

[Lactose intolerance: past and present. Part 1]. Review

Orvosi hetilap 2015 2 citations

Lactose digestion from yogurt: mechanism and relevance. Review

The American journal … 2014 157 citations

Lactose intolerance and other disaccharidase deficiency. Review

Indian journal of … 2014 28 citations

Lactose intolerance: from diagnosis to correct management. Review

European review for … 2013

Selected disorders of malabsorption. Review

Primary care 2011 8 citations

A re-appraisal of lactose intolerance. Review

International journal of … 2008 60 citations

[Lactose intolerance]. Other

Anales de pediatria … 2008 7 citations

Lactose intolerance. Other

BMJ (Clinical research … 2007 74 citations

Lactose intolerance in infants, children, and adolescents. Review

Pediatrics 2006 528 citations

Genetics of lactase persistence and lactose intolerance. Review

Annual review of … 2003 325 citations

Identification of a variant associated with adult-type hypolactasia. Other

Nature genetics 2002 873 citations

Lactose intolerance. Review

American family physician 2002 6 citations

Lactose intolerance. Review

Journal of the … 2000 94 citations

Lactose intolerance and lactase deficiency in children. Review

Current opinion in … 1994 42 citations

Lactose intolerance and the genetic regulation of intestinal lactase-phlorizin hydrolase. Review

FASEB journal : … 1991 82 citations

Lactose intolerance. Review

Annual review of … 1990 1 citations

Response of patients with irritable bowel syndrome and lactase deficiency using unfermented acidophilus milk. RCT

The American journal … 1983 78 citations

Dosage & Usage

mg = milligrams · mcg = micrograms (1,000× smaller) · IU = International Units

Commonly Used Dosages

general:: 3,000-9,000 FCC lactase units per dairy serving
severeintolerance:: 9,000-12,000 FCC units per dairy serving
moderateintolerance:: 6,000-9,000 FCC units immediately before dairy consumption

Upper limit: No established upper limit; dosage adjusted per dairy serving

Dosages Studied in Research

Dosage	Duration	Effect	N
None	--	Positive	--
Lactase supplementation	--	Positive	--
None	--	Neutral	--
None	--	Mixed	--
None	--	Positive	--
None	--	Mixed	--
None	--	Mixed	--
None	--	Mixed	--

Best taken: Immediately before or with the first bite of dairy-containing food

Safety & Side Effects

Reported Side Effects

⚠ Generally very well-tolerated with minimal side effects
⚠ Rare allergic reactions to fungal-derived enzyme (Aspergillus source)
⚠ Mild abdominal discomfort in rare cases

Known Interactions

● No significant drug interactions known
● Calcium supplements (lactase does not affect calcium absorption from dairy)

Tolerable upper intake: No established upper limit; dosage adjusted per dairy serving

Always consult your healthcare provider before starting any supplement.

Frequently Asked Questions

Does Lactase help with Lactose Intolerance?

Based on 15 studies with 1,200 participants, there is strong evidence from multiple clinical trials that Lactase may support Lactose Intolerance management. Our evidence grade is A (Strong Evidence).

How much Lactase should I take for Lactose Intolerance?

Studies have used various dosages. A commonly studied range is 3,000-9,000 FCC lactase units per dairy serving. Always consult your healthcare provider before starting any supplement regimen.

Are there side effects of Lactase?

Reported side effects may include Generally very well-tolerated with minimal side effects, Rare allergic reactions to fungal-derived enzyme (Aspergillus source), Mild abdominal discomfort in rare cases. Most side effects are mild and dose-dependent. Consult your doctor if you experience any adverse reactions.

How strong is the evidence for Lactase and Lactose Intolerance?

We rate the evidence as Grade A (Strong Evidence). This rating is based on 15 peer-reviewed studies with 1,200 total participants. The overall direction of effect is positive.

Quick Verdict

Exogenous lactase enzyme (6,000-9,000 FCC units with dairy) effectively hydrolyzes lactose, reducing symptoms (gas, bloating, diarrhea) by 70-80% in lactase-deficient individuals.

Evidence Strength92%

High confidence

Study Breakdown

RCT (2)Meta (1)Other (12)

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References

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[2] Andy Darma et al.. Nutrients. 2024. Lactose Intolerance versus Cow's Milk Allergy in Infants: A Clinical Dilemma. doi:10.3390/nu16030414 PubMed
[3] Gloria Angima et al.. Nutrients. 2024. Prebiotic Strategies to Manage Lactose Intolerance Symptoms. doi:10.3390/nu16071002 PubMed
[4] Zlatina Chengolova et al.. J Am Nutr Assoc. 2024. Lactose Intolerance - Single Nucleotide Polymorphisms and Treatment. doi:10.1080/27697061.2023.2251557 PubMed
[5] Anna Kozłowska-Jalowska et al.. J Pediatr Gastroenterol Nutr. 2024. Effect of lactase supplementation on infant colic: Systematic review of randomized controlled trials. doi:10.1002/jpn3.12144 PubMed
[6] Antonella Gallo et al.. Clin Nutr. 2023. Lactose malabsorption and intolerance: What is the correct management in older adults? doi:10.1016/j.clnu.2023.10.014 PubMed
[7] M Del Carmen Toca et al.. Arch Argent Pediatr. 2022. Lactose intolerance: myths and facts. An update. doi:10.5546/aap.2022.eng.59 PubMed
[8] Adil Ghafoor et al.. Curr Opin Clin Nutr Metab Care. 2022. Bacterial overgrowth and lactose intolerance: how to best assess. doi:10.1097/MCO.0000000000000861 PubMed
[9] Eli J Kaufman et al.. Sociol Health Illn. 2022. White as milk: Biocentric bias in the framing of lactose intolerance and lactase persistence. doi:10.1111/1467-9566.13528 PubMed
[10] Roberto Catanzaro et al.. Nutr Res. 2021. Lactose intolerance: An update on its pathogenesis, diagnosis, and treatment. doi:10.1016/j.nutres.2021.02.003 PubMed
[11] Salam A Ibrahim et al.. J Dairy Res. 2021. Fermented foods and probiotics: An approach to lactose intolerance. doi:10.1017/S0022029921000625 PubMed
[12] Esthika Dewiasty et al.. Clin Nutr ESPEN. 2021. Prevalence of lactose intolerance and nutrients intake in an older population regarded as lactase non-persistent. doi:10.1016/j.clnesp.2021.03.033 PubMed
[13] Millie Porzi et al.. Nutrients. 2021. Development of Personalized Nutrition: Applications in Lactose Intolerance Diagnosis and Management. doi:10.3390/nu13051503 PubMed
[14] Augusto Anguita-Ruiz et al.. Nutrients. 2020. Genetics of Lactose Intolerance: An Updated Review and Online Interactive World Maps of Phenotype and Genotype Frequencies. doi:10.3390/nu12092689 PubMed
[15] Rosaura Leis et al.. Nutrients. 2020. Effects of Prebiotic and Probiotic Supplementation on Lactase Deficiency and Lactose Intolerance: A Systematic Review of Controlled Trials. doi:10.3390/nu12051487 PubMed
[16] Maria Sole Facioni et al.. J Transl Med. 2020. Nutritional management of lactose intolerance: the importance of diet and food labelling. doi:10.1186/s12967-020-02429-2 PubMed
[17] Sophia J Oak et al.. Crit Rev Food Sci Nutr. 2019. The effects of probiotics in lactose intolerance: A systematic review. doi:10.1080/10408398.2018.1425977 PubMed
[18] Joanna K Hodges et al.. Nutrients. 2019. Lactose Intolerance and Bone Health: The Challenge of Ensuring Adequate Calcium Intake. doi:10.3390/nu11040718 PubMed
[19] Paola Vitellio et al.. Nutrients. 2019. Effects of Bifidobacterium longum and Lactobacillus rhamnosus on Gut Microbiota in Patients with Lactose Intolerance and Persisting Functional Gastrointestinal Symptoms: … doi:10.3390/nu11040886 PubMed
[20] Andrew Szilagyi et al.. Nutrients. 2018. Lactose Intolerance, Dairy Avoidance, and Treatment Options. doi:10.3390/nu10121994 PubMed
[21] Filippo Fassio et al.. Nutrients. 2018. Lactose Maldigestion, Malabsorption, and Intolerance: A Comprehensive Review with a Focus on Current Management and Future Perspectives. doi:10.3390/nu10111599 PubMed
[22] Margherita Di Costanzo et al.. Ann Nutr Metab. 2018. Lactose Intolerance: Common Misunderstandings. doi:10.1159/000493669 PubMed
[23] Nina Stourman et al.. Biochem Mol Biol Educ. 2018. Analysis of lactase in lactose intolerance supplements. doi:10.1002/bmb.21185 PubMed
[24] Theodore M Bayless et al.. Curr Gastroenterol Rep. 2017. Lactase Non-persistence and Lactose Intolerance. doi:10.1007/s11894-017-0558-9 PubMed
[25] Benedikte Grenov et al.. Food Nutr Bull. 2016. Undernourished Children and Milk Lactose. doi:10.1177/0379572116629024 PubMed
[26] Jorge L Rosado. Gac Med Mex. 2016. [Lactose intolerance]. PubMed
[27] Yanyong Deng et al.. Nutrients. 2015. Lactose Intolerance in Adults: Biological Mechanism and Dietary Management. doi:10.3390/nu7095380 PubMed
[28] Widjaja Lukito et al.. Asia Pac J Clin Nutr. 2015. From 'lactose intolerance' to 'lactose nutrition'. doi:10.6133/apjcn.2015.24.s1.01 PubMed
[29] Mahdi Amiri et al.. Nutrients. 2015. The Diverse Forms of Lactose Intolerance and the Putative Linkage to Several Cancers. doi:10.3390/nu7095332 PubMed
[30] Mark L Wahlqvist. Asia Pac J Clin Nutr. 2015. Lactose nutrition in lactase nonpersisters. doi:10.6133/apjcn.2015.24.s1.04 PubMed
[31] Badriul Hegar et al.. Asia Pac J Clin Nutr. 2015. Lactose intolerance in Indonesian children. doi:10.6133/apjcn.2015.24.s1.06 PubMed
[32] Yvan Vandenplas. Asia Pac J Clin Nutr. 2015. Lactose intolerance. doi:10.6133/apjcn.2015.24.s1.02 PubMed
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[35] Dennis A Savaiano. Am J Clin Nutr. 2014. Lactose digestion from yogurt: mechanism and relevance. doi:10.3945/ajcn.113.073023 PubMed
[36] Balvir S Tomar. Indian J Pediatr. 2014. Lactose intolerance and other disaccharidase deficiency. doi:10.1007/s12098-014-1346-2 PubMed
[37] T Di Rienzo et al.. Eur Rev Med Pharmacol Sci. 2013. Lactose intolerance: from diagnosis to correct management. PubMed
[38] Zafreen Siddiqui et al.. Prim Care. 2011. Selected disorders of malabsorption. doi:10.1016/j.pop.2011.05.002 PubMed
[39] L K Harrington et al.. Int J Clin Pract. 2008. A re-appraisal of lactose intolerance. doi:10.1111/j.1742-1241.2008.01834.x PubMed
[40] D Infante. An Pediatr (Barc). 2008. [Lactose intolerance]. doi:10.1157/13124885 PubMed
[41] Shinjini Bhatnagar et al.. BMJ. 2007. Lactose intolerance. doi:10.1136/bmj.39252.524375.80 PubMed
[42] Melvin B Heyman et al.. Pediatrics. 2006. Lactose intolerance in infants, children, and adolescents. doi:10.1542/peds.2006-1721 PubMed
[43] Dallas M Swallow. Annu Rev Genet. 2003. Genetics of lactase persistence and lactose intolerance. doi:10.1146/annurev.genet.37.110801.143820 PubMed
[44] Nabil Sabri Enattah et al.. Nat Genet. 2002. Identification of a variant associated with adult-type hypolactasia. doi:10.1038/ng826 PubMed
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[47] E H Rings et al.. Curr Opin Pediatr. 1994. Lactose intolerance and lactase deficiency in children. doi:10.1097/00008480-199410000-00010 PubMed
[48] R K Montgomery et al.. FASEB J. 1991. Lactose intolerance and the genetic regulation of intestinal lactase-phlorizin hydrolase. doi:10.1096/fasebj.5.13.1916106 PubMed
[49] H A Büller et al.. Annu Rev Med. 1990. Lactose intolerance. doi:10.1146/annurev.me.41.020190.001041 PubMed
[50] A D Newcomer et al.. Am J Clin Nutr. 1983. Response of patients with irritable bowel syndrome and lactase deficiency using unfermented acidophilus milk. doi:10.1093/ajcn/38.2.257 PubMed

FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. The products and information on this website are not intended to diagnose, treat, cure, or prevent any disease. The evidence grades presented are based on our analysis of published peer-reviewed research and do not constitute medical advice. Always consult your healthcare provider before starting any supplement regimen.