OmneDiem Science

The Science Behind OmneDiem®

Backed by Research, Not Trends

For more than a decade, OmneDiem has helped lead histamine intolerance research and education in the United States. Here's the published science behind the ingredient categories we formulate with.


We build our formulations on ingredient forms that have been studied in published, peer-reviewed research — then we manufacture them to clean, transparent standards. Below is a plain-language tour of that science, organized by the two pillars of our product line: DAO enzyme support for histamine balance and creatine for women in midlife.

PILLAR 01

Diamine Oxidase (DAO) & Histamine Balance

Think of DAO as your gut's cleanup crew for dietary histamine. Histamine is a natural compound found in aged, fermented, and leftover foods. Normally, an enzyme called diamine oxidase (DAO) breaks it down in the small intestine before it builds up. When DAO activity is low, that cleanup falls behind — and histamine can accumulate, which researchers associate with a range of everyday discomforts.

STEP 1

Histamine enters the body through food, primarily via the small intestine.

STEP 2

DAO is the main enzyme that degrades histamine in the gut.

STEP 3

When DAO activity is low, histamine can accumulate and trigger discomfort.

STEP 4

Supplemental DAO, taken before meals, aims to support that degradation.

Interventional Pilot Study

DAO supplementation and histamine intolerance symptoms

Key finding: Across 28 participants, symptom scores improved during four weeks of taking DAO before meals, and rose again once supplementation stopped.

An open-label study had participants with histamine intolerance take DAO capsules before meals for four weeks, then stop. Using a 22-symptom questionnaire across gastrointestinal and extra-intestinal categories, researchers reported that symptom sum-scores decreased during supplementation and increased again during the no-DAO follow-up period.

Schnedl WJ, et al. Food Science and Biotechnology (2019). ClinicalTrials.gov NCT03298568. · PubMed

Randomized Double-Blind Trial

DAO and headache frequency in adults with DAO deficiency

Key finding: In adults with measured DAO deficiency, supplemental DAO was associated with reduced headache outcomes versus placebo.

A randomized, double-blind, placebo-controlled trial examined exogenous DAO in adults who had reduced DAO activity. The researchers framed supplemental DAO as a strategy to enhance the breakdown of dietary histamine in people whose own enzyme activity is insufficient.

Izquierdo-Casas J, et al. Clinical Nutrition (2019); 38:152–158. · ScienceDirect

Observational Study

Efficacy & safety of DAO supplementation in histamine intolerance

Key finding: Weekly symptom tracking showed improvement across five symptom categories — nervous system, gastrointestinal, respiratory, skin, and circulatory.

An observational study evaluated DAO supplementation using a standardized questionnaire that scored severity (0–5) across five symptom subcategories at baseline and every week through the study period.

O'Connor ME, et al. Clinical Nutrition ESPEN (2023). · Clinical Nutrition ESPEN

Phase I Safety Trial

Safety and tolerability of ascending DAO doses

Key finding: A randomized, double-blind Phase I design evaluated single ascending doses of DAO in healthy volunteers to assess safety and tolerability.

Thirty healthy participants were randomized to DAO or placebo, with single doses administered under fasting conditions — part of the broader effort to characterize DAO supplementation in controlled clinical settings.

Phase I single-ascending-dose trial. medRxiv preprint (2024). · medRxiv

The OmneDiem Difference: We Dug the Well

The clinical research validating DAO supplementation has been built primarily on porcine-sourced DAO — the same category of material at the heart of our formulations. It's worth knowing that some plant- and pea-based competitors point to that same porcine clinical data to support their own products. We didn't follow this category into the U.S. market; we helped establish it — which is why other supplement brands source raw enzyme material from us.

PILLAR 02

Creatine for Women in Midlife

Creatine is one of the most-studied dietary supplements in the world — and a growing body of research focuses specifically on women in perimenopause and beyond. The big-picture reason: women naturally produce less creatine than men, and the hormonal shifts of midlife coincide with changes in muscle, bone, and cognition. Creatine is being studied as a simple daily lever on several of those at once.

2-Year Randomized Controlled Trial

Creatine, resistance training & postmenopausal bone health

Key finding: Over a yearlong intervention, a creatine-plus-training group showed substantially less bone-density loss at the femoral neck than the placebo group.

Researchers studying postmenopausal women combined daily creatine monohydrate with supervised resistance training, focusing on bone mineral density at the hip — the most clinically relevant site for fracture risk. The work reinforced both the practicality and long-term safety of daily creatine dosing in this population.

Chilibeck PD, Candow DG, et al. 2-year RCT on creatine for postmenopausal bone health. · ClinicalTrials.gov

Systematic Review & Meta-Analysis

Creatine + resistance training for muscle strength in older women

Key finding: Adding creatine to resistance training produced significant strength gains versus training alone — especially in programs lasting 24 weeks or longer.

A 2021 systematic review and meta-analysis of randomized trials in older females concluded that the combination of creatine and resistance training outperformed training by itself for muscle strength, with longer programs delivering more benefit.

dos Santos EEP, et al. Nutrients (2021); 13(11):3757. · MDPI

Narrative Review

Creatine across women's life stages

Key finding: Beyond muscle, reviewers highlight creatine's studied roles in mood, cognition, and bone health when combined with resistance training in postmenopausal women.

A comprehensive review of creatine in women's health traced supplementation across menstruation, pregnancy, and menopause, noting that female hormones influence creatine metabolism — a reason dosing and context matter for women specifically.

Creatine in women's health (narrative review). JISSN (2025). · Journal of the ISSN

Randomized Controlled Trial

Creatine, cognition & mood in peri- and postmenopausal women

Key finding: In a small RCT, eight weeks of creatine supplementation was associated with improved reaction time and reduced mood-swing severity.

A 2025 randomized controlled trial of women in perimenopause or postmenopause examined creatine's effect on cognitive measures and mood, part of a fast-growing research area on creatine and the midlife brain. A separate 2024 analysis of 16 clinical trials in adults likewise linked creatine to improvements in memory, attention, and processing speed.

RCT in peri-/postmenopausal women (2025); plus 2024 multi-trial cognitive analysis. · PMC

From Research to Bottle

Good science only matters if it survives the trip from the lab to your supplement. That's where a lot of products fall short — citing impressive studies, then formulating with cheaper or unstudied ingredient forms. We hold the line in three places:

WE USE

The studied form. Research-grade ingredient forms that match the published literature — not lower-cost substitutes.

WE MAKE

It clean. Manufactured domestically under cGMP, with European-sourced raw materials and tested batches.

WE SHOW

The label. Transparent dosing — what's on the label is what's in the bottle.

The studies referenced above are independent, published, peer-reviewed research on the ingredient categories OmneDiem formulates with (diamine oxidase and creatine monohydrate). They are provided for educational purposes and describe research on these ingredients generally; they are not studies of OmneDiem finished products unless specifically stated. Always consult your healthcare provider before beginning any supplement, particularly if you are pregnant, nursing, or managing a medical condition.

These statements have not been evaluated by the Food and Drug Administration. Our products are not intended to diagnose, treat, cure, or prevent any disease.
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