Clinicians preferred the faster-acting medication because it relieved symptoms sooner.

The fast-acting pain reliever reduced my headache within minutes.

Of all the cold medicines on the shelf, this one is the fastest-acting for easing congestion.

We switched to a slower-acting fertilizer to avoid shocking the young plants.

Among the medications we tested, this was the slowest-acting, producing noticeable effects only after several days.

The slow-acting medication eased his pain over several days.

The committee acted upon the recommendation and implemented the new policy.

The committee, acting upon new evidence, reopened the investigation.

The acted-out scene left the audience speechless.

They whispered about the act of darkness behind the old barn, pretending it was nothing more than a rumor.