Is the fervor over Ozempic just a passing fad? It doesn't appear to be the case after Novo Nordisk (NVO 0.84%) announced its results for the first nine months of 2023 on Thursday morning.

Ozempic sales soared in the third quarter. Unsurprisingly, investors reacted positively to Novo Nordisk's results, with the big drugmaker's shares jumping nearly 4% in early trading.

However, Eli Lilly (LLY 1.19%) reported its Q3 results on Thursday as well, and its share price jumped close to 7%. Is Lilly a better stock to buy than Novo Nordisk?

Novo Nordisk's sizzling quarter

"Sensational" might be the best word to describe Ozempic's recent performance. Novo Nordisk announced that the type 2 diabetes drug raked in Q3 sales of 23.9 million kroner (around $2.1 billion), up 56% year over year using a constant exchange rate.

However, Ozempic's sibling, Wegovy, delivered even more impressive growth. The two products use different doses of the same underlying drug: semaglutide. While Ozempic is frequently prescribed as an off-label treatment for weight loss, Wegovy is approved for the indication. Wegovy's Q3 sales topped 9.6 billion kroner (nearly $900 million), up from 1.1 billion kroner (a little over $100 million) in the prior-year period.

Novo Nordisk's total sales in Q3 increased by 29% year over year on a reported basis and 38% using constant exchange rates. The company raised its full-year growth outlook in October and continues to expect sales will jump between 32% and 38% in 2023 on a constant-currency basis.

Eli Lilly blew the doors off in Q3, too

While Novo Nordisk's Q3 results were very good, Eli Lilly reported even better numbers. Lilly's Q3 revenue soared 37% year over year to nearly $9.5 billion. The company's type 2 diabetes drug Mounjaro continued to gain ground on Ozempic, racking up sales of $1.4 billion in Q3.

Lilly's lineup includes several other rising stars, though. Sales for breast cancer drug Verzenio vaulted 68% higher year over year to over $1 billion. Type 2 diabetes drug Jardiance raked in nearly $701 million, up 22% from the prior-year period. The company also saw strong momentum for relatively new cancer drugs Retevmo and Tyvyt, with sales increases of 56% and 50%, respectively.

Despite Lilly's tremendous revenue growth, the drugmaker's earnings plunged. Lilly posted a net loss of $57.4 million, or $0.06 per share, based on generally accepted accounting principles (GAAP). Its non-GAAP earnings in Q3 declined by 95% year over year to only $94.8 million, or $0.10 per share.

However, investors didn't bat an eye at this seemingly problematic trend. Why? The lower earnings numbers were due to $2.98 billion in charges related to Lilly's acquisitions of Dice Therapeutics, Emergence Therapeutics, and Versanis Bio. Without these nonrecurring expenses, Lilly would have delivered strong profit growth.

Better stock: Novo Nordisk or Eli Lilly?

If we only compared Novo Nordisk and Lilly on earnings-based valuation metrics, Novo would be the clear winner. Novo Nordisk's shares trade at 33 times expected earnings, while Lilly's forward earnings multiple of 43.5 is much higher.

However, those metrics only factor in near-term growth. Over the next decade, I expect Lilly to generate significantly stronger growth than Novo Nordisk will.

Lilly already awaits regulatory approval for Mounjaro in chronic weight loss management. It's likely that Mounjaro's sales will quickly surpass Ozempic's if approved for weight loss. Lilly also hopes to soon win regulatory approval for donanemab in treating Alzheimer's disease. If approved, the drug would almost certainly become yet another blockbuster for the company.

My view is that Eli Lilly is the better stock to buy right now than Novo Nordisk. However, I suspect that both stocks will continue to make money for investors.