Osteoarthritis (OA) is the most common form of arthritis, with typical age of onset in the mid to late 40s. This condition affects your joints. It’s painful and degenerative, which means it gets worse over time. Obesity and prior sports injuries increase the risk of OA.

One of the characteristics of OA is loss of cartilage in your joints. Cartilage acts as a protective cushion, so the loss can be debilitating. It’s particularly common in knee joints. Fortunately, there are several treatment options.

No treatment can reverse OA or regenerate knee cartilage. Still, treatments such as Synvisc and Hyalgan can help ease the knee pain that comes with this condition. These are products used for viscosupplementation. They share similarities as well as 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 helps improve your mobility and decrease your pain. Two products available for this therapy are Synvisc and Hyalgan.

Synvisc (hylan GF 20) and Hyalgan (hyaluronic acid) are both only available as brand-name drugs. They’re made of a naturally occurring substance called hyaluronic acid. This 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 weight reduction (if obesity is a factor) to help ease your OA before prescribing Synvisc or Hyalgan.

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

Neither therapy provides 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 osteoarthritis has not been proved.

Synvisc therapy requires one injection each week for three weeks. Hyalgan therapy requires one injection each week for five weeks.

Both can reduce OA knee pain for up to six months, but results from one comparative 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 both Synvisc and Hyalgan are similar.

Possible side effects of both drugs 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 different treatments for osteoarthritis 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 and Hyalgan are products that work similarly and have excellent safety profiles.

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