side effect

American  

Or side-effect

noun

1. any effect of a drug, chemical, or other medicine that is in addition to its intended effect, especially an effect that is harmful or unpleasant.

2. any accompanying or consequential and usually detrimental effect.

   the side effects of air pollution.

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side effect British  

noun

1. any unwanted nontherapeutic effect caused by a drug Compare aftereffect

2. any secondary effect, esp an undesirable one

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Etymology

Origin of side effect

First recorded in 1880–85

Example Sentences

In addition, Luminate is developing medical devices to deliver cancer medications as well as curb their daunting side effects.

From The Wall Street Journal

This might be because of common side effects such as nausea or the price -- these drugs can cost over $1,000 a month in the US.

From Barron's

The findings highlight a key gap between controlled clinical trials and everyday use, where side effects, costs, and long-term adherence can limit the effectiveness of medication-based weight loss.

From Science Daily

Their work is raising optimism that future pain medications could deliver relief without the life-threatening side effects associated with today's opioids.

From Science Daily

There is still huge demand for new types of weight-loss medications, including pills, as well as drugs with fewer gastrointestinal side effects and medications that don’t lead to muscle loss.

From MarketWatch

Related Words

• aftereffect
• reaction