Enzyme
Pepsin (Aspergillus niger)
Also known as: fungal pepsin, microbial pepsin, Aspergillus niger pepsin, acid protease
Pepsin is a proteolytic enzyme derived from Aspergillus niger fungus that breaks down proteins in acidic environments, primarily used in digestive support supplements. It is commonly paired with betaine HCl to support gastric protein digestion in individuals with low stomach acid.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Every Pepsin (Aspergillus niger) product we have scored
| # | Product | Score | Per serving |
|---|---|---|---|
| 1 | Nutricost Betaine HCI + Pepsin Capsules | 88 A | $0.08 |
| 2 | Thorne Betaine HCL & Pepsin | 88 A | $0.42 |
| 3 | Thorne Multi Enzyme | 87 A | $0.56 |
| 4 | Thorne Advanced Digestive Enzymes | 84 A- | $0.62 |
| 5 | Pure Encapsulations Betaine HCl Pepsin | 83 A- | $0.21 |
| 6 | Integrative Therapeutics Betaine HCl | 80 A- | $0.37 |
| 7 | Bluebonnet Nutrition BETAINE HCI & PEPSIN DIGESTIVE ENZYME | 80 A- | $0.37 |
| 8 | Vital Nutrients Betaine HCl Pepsin Gentian Root Extract | 74 B+ | $0.36 |
| 9 | Bluebonnet Nutrition POWER-ZYMES DIGESTIVE ENZYME | 71 B | $0.47 |
Scored on dose accuracy, form, label transparency and third-party testing. Per-serving cost is list price divided by servings per container. No brand pays to be listed or ranked.
Common questions
How much Pepsin (Aspergillus niger) should I take?
The typical range is 100-500 mg per dose. May be used short-term or as ongoing digestive support; no established maximum duration
When should I take Pepsin (Aspergillus niger)?
With meals, particularly protein-containing meals. Must be taken with food; requires acidic gastric environment to be effective.
Which form of Pepsin (Aspergillus niger) is best?
Capsule. Other forms in the catalog: Tablet.
Is Pepsin (Aspergillus niger) safe?
Commonly reported: Generally well-tolerated, Rare: mild GI discomfort, nausea.
Which Pepsin (Aspergillus niger) supplement scores highest?
Nutricost Betaine HCI + Pepsin Capsules, at 88/100. Scored on dose accuracy, form, label transparency and third-party testing — no brand pays to be listed or ranked.
Primary uses
- Protein digestion support
- Digestive enzyme replacement
- Hypochlorhydria support (low stomach acid)
How it works
- Proteolytic enzyme that cleaves peptide bonds in acidic pH (optimal pH 1.5-2.5)
- Breaks down dietary proteins into smaller peptides for improved absorption
Dosage
- Typical range
- 100-500 mg per dose
- Timing
- With meals, particularly protein-containing meals
- With food
- Must be taken with food; requires acidic gastric environment to be effective
- Duration
- May be used short-term or as ongoing digestive support; no established maximum duration
- Special populations
- Should not be used by individuals with peptic ulcer disease or severe gastritis without medical supervision
Forms
- Capsule· 70/100
- Tablet· 70/100
Safety
Common side effects
- Generally well-tolerated
- Rare: mild GI discomfort, nausea
Contraindications
- Active peptic ulcer disease
- Severe gastritis or esophagitis
- Allergy to Aspergillus species
Products containing Pepsin (Aspergillus niger)
Top-scoring supplements in our catalog that list Pepsin (Aspergillus niger) on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
Evidence notes
Limited clinical evidence specific to Aspergillus niger-derived pepsin. General enzyme therapy shows modest evidence; fungal pepsin efficacy compared to animal-sourced pepsin is not well-established in RCTs. Most evidence is theoretical or from small studies.
Grade C: Mostly observational or small trials; mechanism is plausible but unproven at scale.
Related in Enzyme
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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Individual needs and risks vary — consult a professional before starting, stopping, or combining supplements, especially if you are pregnant or nursing, taking medication, or managing a health condition.