Juul Labs has soared to the top of the United States e-cigarette market in just three years with its high-nicotine products that give off just a wisp of vapor.

Now, facing public backlash and overseas restrictions, the company is working on a way to lower the nicotine in its pods — but still maintain a potent punch from the addictive chemical. Joshua Raffel, a Juul spokesman [...] would only say: “We are always looking to create products that help adult smokers switch from combustible cigarettes and limit appeal to youth.”