SAN FRANCISCO — Cordyceps, lion’s mane and reishi mushrooms are among featured ingredients in a new brand of functional protein bars by San Francisco startup B.T.R. Bar. Founder Ashley Nickelsen designed the products to offer specific benefits: Recharge, Energy and Zen.

“B.T.R. stands for ‘be bold, tenacious and resilient,’ which was my parents’ personal mantra and something I’ve carried with me throughout my life,” she said.

More than four years ago, her parents were diagnosed with rare forms of cancer. Juggling hospital visits and a full-time job led to lots of on-the-go snacks that lacked nutrition. Ms. Nickelsen began creating recipes for healthier alternatives, and this year she launched the business to honor her parents.

“My father worked in legal and trademarks, and he incorporated the company, and right before he passed, he said, ‘I want you to do something with this,’” Ms. Nickelsen said. “And I just knew I needed to do something eventually, and what better time than a pandemic to decide to pull the trigger and move forward?”

B.T.R. Bars have a base of cashew and almond butter, a blend of pea and hemp protein, almond flour and medium-chain triglyceride oil from coconut. Chicory root fiber and monk fruit extract add sweetness. Flavors include dark chocolate brownie, cinnamon cookie dough and cherry chocolate chip.

“A lot of options out there say, ‘We’re a better-for-you snack or a better-for-you bite,’ and then you turn it over and look at the ingredients and there’s all these gums and emulsifiers,” Ms. Nickelsen said. “We are free from natural flavors, sugar alcohols, stevia, gums, emulsifiers, and we have 90% less sugar than the average protein bar. If you’re vegan, keto or gluten-free, you can enjoy these and also get the functional benefits.”

Interest in functional foods and beverages has accelerated, a top trend recently identified by Whole Foods Market, describing a blurring of lines between the supplement and grocery aisles. More brands are incorporating ingredients like vitamin C, mushrooms and adaptogens to boost immunity, enhance focus or support stress relief and relaxation. B.T.R. Bars highlight such ingredients to help consumers “chill out,” “stay sharp” or provide a “pick-me-up.”

Ms. Nickelsen drew on her background in food science and nutrition and partnered with a food scientist and chef to develop the products. She also has built the B.T.R. Collective, a group of registered dieticians, nutritionists, doctors and dentists who provide feedback and recommendations on ingredients. And she taps into a sprawling social community of influencers and brand ambassadors to guide product innovation. Two additional flavors are in development.

“I wanted to start in the bar category because I used to eat a bar a day and knew that was something that needed cleaning up,” she said. “But I do see the company expanding past bars. I am a grazer. I love to snack throughout the day, and I think it would really serve the snack space to have cookies or brownies and things that have superfoods and adaptogens in them and taste really good.”

The bars are currently sold at the brand’s website, eatbtrbar.com, and through online retailers such as Bubble Goods and Zippy Pantry. Ms. Nickelsen is planning to launch the brand into natural grocery stores next year.

“Every single thing I do in the business… my parents, I can feel them,” she said. “They just shine through me, and that’s how I run the business.”