SAN FRANCISCO — Greg Yeutter is trying to build a better night’s sleep.

His company, Restful, produces lighting designed to align with the body’s natural rhythms: bulbs that dim blue light before bed and lamps that simulate sunrise in the morning. The products have begun to gain traction in the United States and Canada, and Mr. Yeutter hopes they will soon reach a global market.

But as Restful grows, it is confronting a challenge far removed from circadian science: the unpredictability of tariffs.

“We are a lighting company. We make lighting for better sleep,” Mr. Yeutter said. “We have a very popular product in the U.S. called the Bedtime Bulb, and we’re introducing a smart lamp that helps you prepare for sleep and wake up with energizing light.”

For all its promise, Restful’s expansion is tethered to a global supply chain that has become increasingly difficult to navigate. Like many small manufacturers, the company depends heavily on production in China — not out of preference, Mr. Yeutter said, but necessity.

“The expertise really only exists in China for manufacturing,” he said. “There aren’t really glass factories that do this type of work at scale elsewhere.”

Trade agreements like the United States-Mexico-Canada Agreement have made it possible to source some components in North America. But critical parts, particularly specialized glass enclosures, remain difficult to produce outside Asia, limiting the company’s ability to shift production closer to home.

For policymakers eager to encourage domestic or regional manufacturing, the reality on the ground can be more complicated.

Tariffs, intended in part to reshape supply chains, have introduced a different set of pressures for companies like Restful. For Mr. Yeutter, the issue is not only the added cost, but the uncertainty surrounding it.

“It actually feels like a bit of roulette,” he said. “It’s stated as one thing, but then we get a bill from the shipping company that’s different.”

That unpredictability, he said, reverberates through nearly every aspect of the business, from pricing decisions to hiring plans. For a young company still establishing its brand, the consequences can be immediate.

“We have to price the product higher to be able to sell it profitably, or even at break-even,” he said. “And then we get fewer customers, especially since we’re a new brand.”

In effect, tariffs can function as a brake on adoption, raising prices at a moment when companies are trying to build trust and market share.

Mr. Yeutter also sees a broader shift underway: a U.S. market that is becoming more complex and, in some ways, more difficult to enter.

“If you compare the U.S. to the E.U., the E.U. has a lot of regulation, and that’s very challenging,” he said. “But now the U.S. market is almost as difficult to enter as the E.U.”

For a country that has long positioned itself as a hub for innovation and entrepreneurship, that trend is troubling, he said.

“That’s not what you want if you’re trying to promote innovation for American brands.”

Mr. Yeutter does not dismiss the strategic logic behind tariffs or efforts to diversify supply chains. Reducing reliance on any single country, he acknowledged, can serve broader economic and national interests.

“We understand that it might be strategic to not have everything go through China,” he said.

But he argues that the design of those policies, and the pace at which they are implemented, can make a significant difference for small businesses.

“Predictability and some time to adapt, and making it not just a stick approach, but a carrot-and-stick approach: that’s what would be super helpful,” he said.

Such an approach, he suggested, would give companies like Restful a clearer path to adjust their operations, explore manufacturing options within North America and remain competitive as they grow.

For now, Restful continues to push forward, buoyed by early customer demand and the promise of a new product category. But like many young companies navigating a shifting trade landscape, its trajectory may depend as much on policy stability as on product innovation.