Osteoarthritis (OA) is the most common form of arthritis. It’s painful and degenerative, which means it gets worse over time. Although it often occurs in older adults, younger adults can develop OA too.

One of the characteristics of OA is loss of cartilage in your joints. Cartilage acts as a protective cushion, so the loss can be quite painful. OA is particularly common in knee joints.

While no treatment can reverse OA or regenerate knee cartilage, treatments can provide relief and improve your quality of life.

Synvisc and Hyalgan are two treatments that can help ease the knee pain that comes with OA. These are products used for viscosupplementation. Read on to learn about their similarities and differences.

Viscosupplementation is a treatment that involves cushioning your knee joint with injections of a gel-like fluid. The fluid acts as a shock absorber and enables the bones to move more smoothly.

This can help improve mobility and decrease pain. The products available for this therapy are Synvisc and Hyalgan.

Synvisc (hylan GF 20) and Hyalgan (hyaluronic acid) are both available as brand-name drugs.

They’re made of a naturally occurring substance called hyaluronic acid. Hyaluronic acid is found in rooster combs (the flesh on top of their head). Hyaluronic acid helps cushion and lubricate your joints.

Both drugs are also considered second-line therapy. That means your doctor will likely have you try pain relievers, physical therapy, and lifestyle modifications to help ease your OA before prescribing Synvisc or Hyalgan.

Both Synvisc and Hyalgan have been proven safe and effective at reducing pain from OA. They’re given by injection directly into the cavity surrounding your knee joint. The injection is given in a doctor’s office.

These therapies don’t provide immediate pain relief. You’ll likely need a series of injections before your pain is reduced.

Even though they’re both made of hyaluronic acid produced from chicken combs, Synvisc is chemically modified to increase its molecular weight. Hyalgan is not.

It’s thought that formulations with higher molecular weight are closer to the molecular weight and elasticity of the natural lubricants in the joints of young people.

However, whether Synvisc is more effective in people with OA hasn’t been proven.

There are two Synvisc options. The newer option, Synvisc-One, is given as a single 6-millileter (mL) injection. The original Synvisc option is given as a 2-mL injection once a week for 3 weeks.

Hyalgan therapy requires one injection each week for 5 weeks.

All options can reduce OA knee pain for up to 6 months, but results from a 2005 study indicated that people using Synvisc could go longer between treatments than people using Hyalgan.

Understanding the possibility of complications and adverse effects is important in making any treatment decision. The side effects of the Synvisc options and Hyalgan are similar.

Possible side effects include:

  • pain, redness, and swelling at the injection site
  • fluid buildup around the joint

Repeat injections of Synvisc may cause a hypersensitivity reaction. This is a set of immune system responses to the product, including allergic responses.

This reaction may be uncomfortable or painful. Hypersensitivity reactions may happen after an injection even if they haven’t happened with previous injections.

OA knee pain becomes a real possibility with aging or injury. While treatments can’t reverse OA damage, they can decrease joint pain to make you more comfortable.

Several treatments for OA exist. Your doctor will recommend a therapy for you based on your medical history and the severity of your OA and joint pain.

If your doctor recommends viscosupplementation, Synvisc, Synvisc-One, and Hyalgan are products that work similarly and are safe.

For information on other possible options, read about OA treatments.