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What is the difference between carbidopa, levodopa, and Rytary?

Medically reviewed by Melisa Puckey, BPharm. Last updated on Feb 13, 2024.

Official answer


Rytary is a brand of medicine containing carbidopa and levodopa, which is used to treat Parkinson’s symptoms.

The difference between Rytary and other brands of carbidopa and levodopa is whether they are an immediate release, controlled release, extended release or a combination of fast or slow release. This affects how

  • quickly or slowly they start to work
  • how long they work for.

Rytary is an extended release capsule which starts working in about an hour and continues to work for 4 to 5 hours then the blood levels start to decrease. The capsules contain microbeads of carbidopa-levodopa that dissolve at different rates. One third of the beads dissolve fast and two thirds of the beads dissolve slowly. This means that when you take a Rytary capsule it starts to work quickly due to the fast dissolving beads and works for a longer time due to the slow dissolving beads.

Because Rytary contains a combined fast release and slow release preparation it is not interchangeable with other brands of carbidopa with levodopa.

For more information on Rytary click here: Rytary: 7 things you should know


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