One question that comes up when considering HA injections is: where does the gel actually come from? The answer might surprise you - some products come from roosters, while others are made by bacteria.
The Two Sources of HA
All hyaluronic acid used in joint injections comes from one of two sources:
Avian (Bird) Derived
Extracted from rooster combs - the red fleshy crest on top of a rooster’s head. This tissue is naturally rich in hyaluronic acid.
Products from avian sources include:
- Synvisc / Synvisc-One
- Hyalgan
- Supartz
Bacterial (Biofermentation) Derived
Produced through fermentation using bacteria (typically Streptococcus species). The bacteria naturally produce hyaluronic acid, which is then purified for medical use.
Products from bacterial sources include:
- Euflexxa
- Monovisc
- Orthovisc
- Gel-One
- Durolane
Does the Source Affect How Well It Works?
Short answer: No.
Clinical studies comparing avian and bacterial-derived HA show:
- Similar pain relief
- Similar duration of benefit
- Both are effective treatments
The final product - purified hyaluronic acid - is chemically identical regardless of the source. Your body can’t tell the difference.
When the Source Does Matter: Allergies
The source becomes important if you have allergies to birds, poultry, feathers, or eggs.
If You Have Bird/Egg Allergies
Choose bacterial-derived products like:
- Euflexxa
- Monovisc
- Orthovisc
- Gel-One
- Durolane
These products carry no risk of triggering bird-related allergies because they never come in contact with birds or bird tissue.
Why Avian Products Could Be a Problem
Even though avian-derived HA is highly purified, trace amounts of bird proteins might remain. For most people, this isn’t an issue. But if you have:
- Allergies to chicken or eggs
- Allergies to feathers
- History of reactions to bird products
…it’s safer to avoid avian-derived products entirely.
Product Comparison by Source
| Source | Products | Allergy-Safe |
|---|---|---|
| Bacterial | Euflexxa, Monovisc, Orthovisc, Gel-One, Durolane | Yes - safe for bird/egg allergies |
| Avian | Synvisc, Synvisc-One, Hyalgan, Supartz | No - avoid if allergic to birds/eggs |
How to Tell Which Type You’re Getting
Always tell your doctor about any allergies before receiving HA injections. They will:
- Review your allergy history
- Select an appropriate product
- Document the source type in your records
If you’re unsure which type was recommended, ask specifically: “Is this product derived from birds or bacteria?”
Other Differences to Know
Beyond allergies, there are a few other considerations:
Cost
Bacterial-derived products sometimes cost slightly more due to the fermentation process, but insurance coverage is usually similar.
Availability
Both types are widely available. Your doctor’s office likely stocks products from both sources.
Effectiveness Studies
Some doctors have personal preferences based on their experience, but scientific evidence shows both types work equally well.
Questions to Ask Your Doctor
- “Which source is this product from?” - Make sure you know what you’re getting
- “Is this safe given my allergy history?” - Discuss any bird, egg, or feather sensitivities
- “Do you have experience with this specific product?” - Their comfort level matters
The Bottom Line
The source of your HA injection - bird or bacteria - doesn’t affect how well the treatment works. What matters is:
- Getting the right product for your allergy profile
- Having an experienced provider perform the injection
- Following up appropriately after treatment
If you have no bird or egg allergies, either source is fine. If you do have these allergies, stick with bacterial-derived products. Either way, you can expect the same level of effectiveness from your treatment.