But even the most powerful drugs lost their effectiveness after only an hour or so.

After the perfect game, he seemed to suddenly lose effectiveness.

But within five to 10 years, the drug usually begins to lose its effectiveness.

They'll pick up your fear and lose half their effectiveness.

Once opened, use up quickly otherwise it will lose its effectiveness.

Nor would the points lose their effectiveness after they received one victim.

Current drugs can slow the disease but eventually lose their effectiveness.

And since the truth was losing its effectiveness in that regard, why not try the other approach?

Over time, however, oil gets dirty and loses its effectiveness.

But if diluted too much they lose effectiveness, and further studies are needed to find out the best way to use them.