MCG,

Welcome to the forum.

I'm not a doctor, so make of this what you will.

"Off" time is a common feature of PD, especially as the disease progresses and the body makes less and less of its own dopamine. But, with close attention to one's medication, "off" time can be reduced

Unfortunately, we can't take dopamine to make up for the loss directly. This is because dopamine does not cross the blood brain barrier. Instead we take levodopa which does cross the BBB. Once in the brain, levodopa can be converted into dopamine.

The first question is: is there enough levodopa in the medication to make up for the deficit? The second (and third and fourth ... ) is: does the body get the most out of the levodopa that is taken?

It's one thing taking levodopa, it's another thing getting it to the part of the brain where it can do some good. Fat in the diet may delay gastric emptying. Protein in the diet may compete for absorption into the blood stream. Bacteria in the gut are thought to affect the absorption of levodopa. And there are chemicals in the blood which try to metabolize the levodopa early (to reduce this, levodopa is usually taken with carbidopa, or similar).

The situation is made more complicated because levodopa has a half-life of only about 90 minutes.

The more you can control these variables the smaller the day to day variations.

John