Papain (Papaya Protease · Cysteine Endopeptidase · Digestive Enzyme)
| CAS No. | 9001-73-4 |
| Class | Enzyme · Cysteine Endopeptidase (EC 3.4.22.2) · Plant Protease |
| Source | Carica papaya (Papaya) — unripe fruit latex (primary); leaves and stem also contain papain family proteases |
| Claim strength | High |
| Buy from Herbuno | Papain 500 TU Enzyme Powder → |
Papaya has been used medicinally throughout tropical Central and South America, the Caribbean, and sub-Saharan Africa for centuries — the unripe fruit's latex was applied topically to wounds and skin lesions, and papaya preparations were consumed for digestive disorders. Papain was first identified in 1879 and became a standard industrial enzyme for meat tenderisation, beer clarification, and pharmaceutical manufacture. Papain is a cysteine endopeptidase active across a wide pH range (3.0–9.5), retaining activity in the acidic gastric environment.
Papain for Protein Digestion, Anti-Inflammation & Digestive Enzyme Blends — Evidence
Protein digestion — broad substrate specificity: Papain's wide pH activity range and broad proteolytic specificity make it one of the most effective digestive enzyme supplements. Clinical studies document reductions in post-meal digestive discomfort and bloating with papain supplementation at 100–500 TU per meal. Claim strength: High.
Multi-enzyme digestive blends: Papain is the standard protease component in multi-enzyme digestive supplement formulations — typically combined with amylase, lipase, and cellulase for comprehensive macronutrient digestive support. Claim strength: High (in combination).
Anti-inflammatory and wound debridement: Topical papain preparations are used clinically for wound debridement. Systemic anti-inflammatory effects are less well-evidenced than bromelain. Claim strength: Moderate.
Papain Dosage, Activity Specification & Formulator Guidance
Clinically referenced dose: 100–500 TU (Tyrosine Units) per meal for digestive applications.
Activity units — TU vs USP vs FCC: Papain activity is expressed in TU, USP units, and FCC units. TU values are assay-method dependent and not directly comparable between different analytical procedures. Confirm the assay method on the CoA.
pH activity range: Papain is active from pH 3.0 to 9.5 — retaining meaningful proteolytic activity in the acidic stomach, the neutral small intestine, and the alkaline duodenum. This distinguishes papain from animal-derived pancreatic enzymes that require near-neutral pH.
Allergen consideration: Papain is derived from papaya and is a known allergen. Individuals with latex allergy may exhibit cross-reactivity (latex-fruit syndrome). Standard allergen disclosure applies.
Pairs with: Bromelain (complementary cysteine protease blend), amylase (carbohydrate digestion), lipase (fat digestion), betaine HCl (gastric acid support).
Frequently Asked Questions — Papain
What is the difference between papain and bromelain?
Both are cysteine endopeptidases with broad proteolytic activity. Papain from papaya is active across pH 3.0–9.5 — effective across the full GI tract. Bromelain from pineapple stem has stronger documented systemic anti-inflammatory evidence. Activity units differ: TU for papain, GDU for bromelain.
Why is papain particularly useful in digestive enzyme blends?
Papain's broad pH activity range means it works across the stomach and intestine without rapid inactivation by gastric acid. Its broad substrate specificity covers diverse protein types including meat, gluten peptides, and legume proteins.
Is papain activity measured the same way as bromelain?
No. Papain uses TU or USP/FCC units. Bromelain uses GDU or MCU. These unit systems are not interchangeable. Always specify both weight and activity units when formulating.
Can people with latex allergy use papain supplements?
Latex-fruit syndrome creates cross-reactivity risk. Standard label precautions include papaya origin disclosure and recommendation to consult a healthcare professional for individuals with latex or papaya allergies.
Claim-strength scale – High = multiple human studies; Moderate = a few trials; Emerging = early lab data.
← Back to Active Compound Index · HerbIQ P02: Extraction · HerbIQ P03: Delivery