Protease

enzymeprotease inhibitor

What is it

Protease is a class of digestive enzymes that break down dietary proteins into smaller peptides and individual amino acids. The body produces several proteases, including pepsin (stomach), trypsin, and chymotrypsin (pancreas), and supplemental proteases are commonly derived from fungal, bacterial, or plant sources.

How it works

Protein digestion begins in the stomach, where hydrochloric acid denatures proteins and pepsin begins cleaving them into shorter peptides. As partially digested food enters the small intestine, pancreatic proteases (trypsin, chymotrypsin, carboxypeptidase, elastase) continue the breakdown, producing dipeptides, tripeptides, and free amino acids that intestinal cells can absorb. Supplemental proteases vary widely in source and specificity. Acid-stable proteases from Aspergillus species are active across a broad pH range and work in both the stomach and small intestine. Bacterial proteases from Bacillus subtilis function at higher pH levels. Plant-based proteases include bromelain (from pineapple) and papain (from papaya), which are used both for digestion and for systemic effects when taken between meals. When taken with meals, proteases support breakdown of dietary protein. When taken between meals on an empty stomach, certain proteolytic enzyme blends are thought to be absorbed intact and may exert systemic anti-inflammatory effects, though this remains an area of ongoing research.

Evidence for 4 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Protein digestion support

Grade C

Moderate evidence

Supplemental protease may help reduce post-meal bloating and discomfort in people with low stomach acid or pancreatic insufficiency. Evidence comes mainly from small trials of multi-enzyme blends rather than isolated protease.

Sinusitis (with bromelain-containing blends)

Grade C

Moderate evidence

Bromelain, a plant protease from pineapple, has shown modest benefit for acute sinusitis symptoms in small trials. Effects are attributed to anti-inflammatory and mucolytic properties.

Functional dyspepsia

Grade C

Moderate evidence

Broad-spectrum digestive enzyme blends containing protease may modestly reduce symptoms of functional dyspepsia. Isolating protease's specific contribution from multi-enzyme studies is difficult.

Exercise recovery and muscle soreness

Grade D

Mixed evidence

Some small trials of proteolytic enzyme blends suggest reduced delayed-onset muscle soreness and faster recovery after intense exercise. Results are mixed, and most studies used proprietary blends rather than isolated protease.

4 commercial forms

Fungal protease (Aspergillus oryzae)

Acid-stable across wide pH range

Most common in digestive enzyme blends. Active in both stomach and small intestine.

Bromelain (Ananas comosus)

Some intact absorption documented

Plant-derived protease from pineapple stem. Used for both digestion and systemic anti-inflammatory effects.

Papain (Carica papaya)

Active across pH 3-10

Plant-derived protease from papaya latex. Used in digestive blends and topical preparations.

Serratiopeptidase

Requires enteric coating

Bacterial protease used primarily for systemic anti-inflammatory purposes rather than digestion.

Dosage

There is no RDA for supplemental protease. Activity is measured in HUT, SAPU, or PC units rather than milligrams. Typical digestive enzyme blends provide 10,000 to 100,000 HUT per serving with meals. Systemic enzyme blends (taken away from food) often use higher activity levels, with daily doses ranging from 50,000 to 500,000 HUT spread across multiple administrations.

When and how to take it

For digestive support, take protease with the first bite of a protein-containing meal. For systemic anti-inflammatory effects (with blends containing bromelain, serratiopeptidase, or nattokinase), take on an empty stomach at least 30 to 60 minutes before food or two hours after. Splitting doses across the day improves systemic exposure. Enteric-coated forms should be swallowed whole.

Safety

Supplemental protease is generally well tolerated. Mild side effects include nausea, heartburn, and loose stools. High doses may cause gastrointestinal irritation. Allergic reactions are possible, particularly to fungal-derived proteases in mold-sensitive individuals. There is no established Tolerable Upper Intake Level. Long-term high-dose use has not been thoroughly studied.

Who should be cautious

People with peptic ulcer disease, gastritis, or active gastrointestinal bleeding should avoid protease supplements without medical supervision. Those on anticoagulants or who are scheduled for surgery within two weeks should discontinue use. Pregnant and breastfeeding women should consult a clinician. Avoid in people with documented allergies to source organisms (mold, pineapple, papaya).

Interactions

Protease may enhance absorption of certain medications or alter the breakdown of protein-bound drugs. People taking blood thinners such as warfarin should use caution with systemic protease blends, as bromelain and similar enzymes may have mild anticoagulant effects. Concurrent use with antibiotics should be monitored, as some proteolytic enzymes may alter antibiotic absorption.

Frequently asked questions

What's the difference between protease, bromelain, and papain?⌄

Bromelain and papain are specific plant-derived proteases. Generic 'protease' on labels usually refers to fungal- or bacterial-derived enzymes. All three break down proteins, but they have slightly different pH ranges, activity profiles, and traditional uses.

Do I need protease supplements?⌄

Healthy adults produce ample protease from the stomach and pancreas. Supplementation is most relevant for people with low stomach acid, chronic digestive symptoms, or those eating large protein meals.

Can protease be taken on an empty stomach?⌄

Yes, for systemic effects. When taken away from food, some proteolytic enzymes (like bromelain or serratiopeptidase) may be partially absorbed intact and exert anti-inflammatory effects. Take with meals for digestive support.

Is protease safe with blood thinners?⌄

Use caution. Bromelain and certain other proteolytic enzymes may have mild anticoagulant effects and could theoretically increase bleeding risk when combined with warfarin or other blood thinners. Discuss with your clinician before use.

When should I stop protease before surgery?⌄

Discontinue protease supplements, especially bromelain and serratiopeptidase, at least 7 to 14 days before scheduled surgery due to potential effects on clotting and inflammation.

References

  • ChEBI: protease inhibitor — ChEBI Database link
  • Wikidata: Protease — Wikidata link

Track Protease with Pilora

Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

Coming to App Store

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you're pregnant, breastfeeding, on medications, or managing a chronic condition.