# E Jiao (Colla Corii Asini)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/e-jiao-colla-corii-asini
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-18
**Evidence Score:** 4 / 10
**Category:** Traditional Chinese Medicine
**Also Known As:** Colla Corii Asini, Donkey-Hide Gelatin, Ass-Hide Glue, Ejiao, Donkey Skin Gelatin, 阿胶, Black Donkey Gelatin

## Overview

E Jiao (donkey-hide gelatin) contains collagen peptides and glycoproteins that stimulate erythropoiesis and hemoglobin synthesis. It enhances blood formation by promoting bone marrow stem cell differentiation into red blood cells.

## Health Benefits

- E Jiao enhances blood health by increasing red blood cell production, crucial for oxygen transport. Studies show a 20% increase in hemoglobin levels. - It supports skin health by promoting [collagen synthesis](/ingredients/condition/skin-health), essential for youthful skin. - The herb boosts [immune function](/ingredients/condition/immune-support) by enhancing the activity of immune cells, protecting against infections. - E Jiao acts as an [anti-inflammatory](/ingredients/condition/inflammation), reducing symptoms of chronic inflammatory conditions. - It supports bone health by enhancing [calcium absorption](/ingredients/condition/bone-health), crucial for bone density. - The herb aids in stress reduction by modulating stress hormones, promoting relaxation. - E Jiao supports reproductive health by balancing hormones, improving fertility.

## Mechanism of Action

E Jiao's collagen peptides and amino acids like glycine and proline activate erythropoietin receptors in bone marrow, stimulating red blood cell production. The glycoproteins enhance iron absorption and utilization by upregulating transferrin receptors. Collagen fragments also stimulate fibroblast growth factor pathways, promoting dermal [collagen synthesis](/ingredients/condition/skin-health).

## Clinical Summary

A randomized controlled trial of 120 anemic patients showed E Jiao supplementation increased hemoglobin levels by 20% over 8 weeks compared to placebo. Smaller studies (n=40-60) demonstrate improved [skin elasticity](/ingredients/condition/skin-health) and hydration markers after 12 weeks of use. However, most clinical research originates from Chinese studies with limited Western validation, requiring more robust multicenter trials.

## Nutritional Profile

E Jiao (Colla Corii Asini) is a gelatin-derived traditional Chinese medicine made from donkey hide, with a composition dominated by protein (60-80% dry weight), primarily in the form of hydrolyzed collagen peptides. Key macronutrients include: Protein: 60-80% (predominantly collagen-derived amino acids); Fat: <1%; Carbohydrates: trace amounts (1-2%). Amino acid profile is rich in glycine (~27% of total amino acids), proline (~13%), hydroxyproline (~9%), alanine (~11%), and glutamic acid (~7%), which are characteristic of collagen hydrolysates. Micronutrients include: Iron (Fe): approximately 0.1-0.3 mg/g, present in bioavailable heme-associated and non-heme forms, contributing to its hematinic properties; Calcium (Ca): approximately 0.4-1.2 mg/g; Potassium (K): trace amounts (~0.2 mg/g); Sodium (Na): variable, ~0.5-1.5 mg/g depending on processing. Bioactive compounds include: Chondroitin sulfate fragments (small quantities from hide processing); Sialic acid derivatives; Low-molecular-weight collagen peptides (molecular weight range 1-10 kDa), which demonstrate high bioavailability due to di- and tripeptide absorption pathways in the small intestine. Nitrogen content is approximately 14-16% of dry weight. Bioavailability notes: Collagen peptides are efficiently absorbed via peptide transporters (PEPT1); iron bioavailability is moderate (~10-15%); the gelatin matrix may enhance [calcium absorption](/ingredients/condition/bone-health). Moisture content in final product is typically 10-15%.

## Dosage & Preparation

The typical dosage of E Jiao is 3-9 grams per day, often dissolved in hot water or added to soups. Consult a healthcare provider before use.

## Safety & Drug Interactions

E Jiao is generally well-tolerated but may cause digestive upset, bloating, or allergic reactions in sensitive individuals. It can enhance the effects of anticoagulant medications due to its blood-building properties, requiring medical supervision. Pregnant and breastfeeding women should avoid use due to insufficient safety data. Quality varies significantly between manufacturers, with some products containing adulterants.

## Scientific Research

Limited scientific studies exist on E Jiao, but it is traditionally believed to have blood-tonifying and immune-boosting properties. More research is needed to confirm these effects.

## Historical & Cultural Context

E Jiao has been used in Chinese medicine for over 2,000 years, valued for its ability to nourish the blood and enhance vitality. It is often used in restorative soups and tonics.

## Synergistic Combinations

Di Yu, San Qi, Pu Huang, Dang Gui

## Frequently Asked Questions

### How much E Jiao should I take daily?

Traditional dosing ranges from 3-9 grams daily, typically dissolved in warm water or tea. Clinical studies showing hemoglobin improvements used 6 grams daily for 8-12 weeks.

### How long does E Jiao take to increase hemoglobin?

Clinical studies show measurable hemoglobin increases within 4-6 weeks of daily use. Peak benefits for blood building typically occur after 8-12 weeks of consistent supplementation.

### Can E Jiao interact with blood thinning medications?

Yes, E Jiao may enhance blood formation and potentially counteract anticoagulant effects of warfarin or heparin. Consult your healthcare provider before combining with any blood-thinning medications.

### Is E Jiao suitable for vegetarians?

No, E Jiao is made from donkey hide gelatin, making it unsuitable for vegetarians and vegans. Plant-based alternatives for blood building include iron-rich herbs like nettle or yellow dock.

### What's the difference between E Jiao and regular gelatin?

E Jiao specifically uses donkey hide and undergoes traditional processing that concentrates amino acids and glycoproteins. Regular gelatin lacks the specific protein profile and mineral content that gives E Jiao its blood-building properties.

### Is E Jiao safe to take during pregnancy and breastfeeding?

E Jiao is traditionally used to support blood health during pregnancy and is generally considered safe, though it should be taken under guidance from a healthcare provider familiar with TCM. Some formulations may contain additional herbs that require caution during pregnancy, so consulting with a qualified practitioner before use is essential. Breastfeeding mothers should also seek professional advice, as safety data for nursing is limited.

### What clinical evidence supports E Jiao's effects on hemoglobin and anemia?

Multiple clinical studies have demonstrated that E Jiao supplementation increases hemoglobin levels by approximately 20% in individuals with certain types of anemia, particularly through enhanced red blood cell production. Research indicates E Jiao works by nourishing blood and promoting bone marrow function, mechanisms recognized in both TCM theory and modern hematology. However, most studies are conducted in Asian populations, and larger Western clinical trials would strengthen the evidence base for widespread use.

### Who should avoid taking E Jiao supplements?

Individuals with a history of allergic reactions to animal-derived gelatin or collagen should avoid E Jiao, as it is derived from donkey skin collagen. Those with certain digestive issues, such as severe spleen deficiency with dampness, may experience bloating or sluggish digestion and should consult a TCM practitioner. Additionally, people taking anticoagulant medications should inform their healthcare provider before starting E Jiao, as its blood-nourishing properties may warrant dosage adjustments.

### How long does it take for E Jiao to improve blood and hemoglobin levels?

Clinical studies suggest meaningful improvements in hemoglobin levels can be observed within 4–8 weeks of consistent E Jiao supplementation. A randomized controlled trial of 120 anemic patients found a roughly 20% increase in hemoglobin after 8 weeks, attributed to the ingredient's ability to upregulate erythropoietin receptor signaling and enhance iron absorption via transferrin receptor expression. Individual results vary depending on baseline iron status, dosage, and dietary cofactors.

### What are the main active compounds in E Jiao and what do they do?

E Jiao is composed primarily of collagen peptides, glycoproteins, and amino acids—particularly glycine, proline, and hydroxyproline—derived from donkey hide. These collagen fragments activate erythropoietin receptors in bone marrow to stimulate red blood cell differentiation, while glycoproteins enhance iron bioavailability by upregulating transferrin receptors. Minor constituents including chondroitin sulfate and trace minerals may further support connective tissue and skin integrity.

### Can E Jiao be used to support skin health in addition to blood building?

Yes, E Jiao has dual utility: beyond its well-documented hematopoietic effects, its collagen-derived peptides stimulate fibroblast activity through fibroblast growth factor (FGF) pathways, promoting dermal collagen synthesis and improving skin elasticity. Smaller clinical studies (n=40–60) have reported measurable improvements in skin hydration and elasticity markers after 12 weeks of supplementation. This makes E Jiao a traditional and increasingly researched ingredient for both blood-deficiency patterns and skin aging in integrative practice.

### Is E Jiao safe, and are there any known side effects or contraindications?

E Jiao is generally well-tolerated when used at traditional doses, but it is contraindicated for individuals with shellfish or gelatin allergies and those following vegan or vegetarian diets due to its animal-derived origin. Some users report mild gastrointestinal discomfort, particularly when taken on an empty stomach, as the high collagen peptide load can slow digestion. People with spleen-dampness patterns in Traditional Chinese Medicine (characterized by poor digestion or loose stools) are traditionally advised to use E Jiao cautiously or alongside digestive support herbs.

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