overseeding after use of corn gluten meal

Hi - I'm a newbie to this site. Hopefully someone will have an answer to this question: I spread corn gluten meal on my lawn this spring. I had planned to overseed in the spring, then realized that the corn gluten meal would prevent my grass seed from germinating! Unfortunately, my lawn is full of weeds (which I am hand picking!) & seems thin & sad! I would like to add compost & overseed the lawn to improve its health. Do I have to wait till the fall or next year to do this, or can I overseed now? I live in the Prairies in Canada: it's hot & sunny thru most of July & some of August (zone 3).

Preen Vegetable Garden Weed Preventer contains 100% corn gluten meal.  They recommend application every 4 weeks.  When I was using it, I could go a week or two longer before I would notice new weeds sprouting.

I do believe I read that corn gluten meal builds up in the soil, so more applications would create a longer application time.

If I were you I would test a small patch and see how it does.  I would think you would know within a week to 10 days if your seed is going to germinate.