In the GLP-1 weight loss market, it's largely been a two-horse race between Eli Lilly and Novo Nordisk (NVO -3.62%). The two companies have approved weight loss drugs that are generating billions in revenue, and there's still much more growth on the horizon. Over the past 12 months, however, it's been Eli Lilly that has been the far better buy, rising more than 17%, while Novo Nordisk's stock has fallen by over 30%.

But investors shouldn't read too much into this performance as Novo Nordisk just posted a solid quarter, and there's plenty of reason to remain bullish on the healthcare stock this year. Here's why the stock may be a no-brainer buy right now.

Novo Nordisk's sales and profits soared in Q4

Last week, Novo Nordisk released its year-end results, including how it performed over the last three months of 2024. Net sales for the quarter totaled 85.7 billion Danish kroner ($12 billion) and rose by 30% year over year. Its quarterly profit of 28.2 billion Danish kroner ($3.9 billion) increased by a slightly lower rate of 29%, but it came in comfortably higher than the 26.1 billion Danish kroner ($3.7 billion) that analysts were expecting.

All in all, it was a solid quarter for the business, with the company's GLP-1 weight loss treatment, Wegovy, more than doubling its sales during the period. The company is expecting a more modest growth rate moving forward, however, with sales expected to rise between 16% and 24% this year. It projects its operating profit to rise between 19% and 27%. Both growth rates are at constant exchange rates.

The results, unfortunately, weren't enough to lift shares of Novo Nordisk much higher, as investors likely weren't thrilled with the slowing growth projections. However, as the company builds out manufacturing capacity to ensure it can meet demand for its products, its growth rate may accelerate in the future.

And there's one thing investors should watch out for later this year, which could light a fire under the healthcare stock and finally get it going.

Oral weight loss pill could soon obtain approval

Wegovy is a weekly injectable weight loss treatment, which may not be ideal for all patients. The company has, however, been working on a weight loss pill, which could be a game-changer for the market. Whichever healthcare business has the more effective pill could be the one that rakes in the most sales in the GLP-1 market.

Novo Nordisk CEO Lars Fruergaard Jørgensen says that the company plans to file for regulatory approval for its oral weight loss drug in the U.S. in the next few months, and if all goes well, it may be able to launch as early as next year. Eli Lilly also says its oral pill may be available next year.

When Novo Nordisk files for approval for the drug, that could generate excitement around the stock, potentially resulting in a big, overdue rally.

Novo Nordisk is an underrated stock to buy right now

Although Novo Nordisk's stock has been struggling of late, this is still an exceptionally strong business to invest in. It's growing at a solid rate, and its profit margin is also high. The stock's valuation is attractive as it trades at a forward price-to-earnings multiple (based on analyst estimates) of just 23. That's much cheaper than rival Eli Lilly, which trades at more than 38 times its expected future profits.

While both stocks are good buys for the long haul, Novo Nordisk may have more upside this year, given its significantly lower valuation.