Eli Lilly vs Viking Therapeutics: Which GLP-1 Stock Is the Better Buy?

GLP-1 drugs are proving helpful for many conditions, not just weight loss. In studies, they have shown they can reduce cardiovascular risk, sleep apnea, and even curb addictions. They have the potential to truly transform healthcare, and thus, the opportunity here is significant.

Analysts at Grand View Research estimate that the global GLP-1 drug market will be worth more than $185 billion by 2033. That translates into a compounded annual growth rate of 12.4% between now and then, as the market was worth $66.4 billion last year.

A couple of stocks that are intriguing options in the GLP-1 market are Eli Lilly (NYSE: LLY) and Viking Therapeutics (NASDAQ: VKTX). The former is a heavyweight in the healthcare sector, with a valuation right around $1 trillion, and it's a rock-solid company. The latter is much smaller, but in return, it may offer more upside. Which stock is the better buy if you want to take advantage of the growth opportunities in GLP-1?

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Eli Lilly is dominant, but its valuation is also high

Eli Lilly is the most valuable healthcare stock today, due to the impressive success of its GLP-1 drugs, Mounjaro and Zepbound. They are generating billions in revenue for the business and have resulted in a significant acceleration of Eli Lilly's growth rate. In the past, it wouldn't have been uncommon to see the company's growth rate in single digits or lower. Now, however, it's firing on all cylinders, and its growth rate was an impressive 56% during the first three months of 2026, with its revenue totaling $19.8 billion. Profits also nearly tripled, rising from $2.8 billion to $7.4 billion.

The company's incredibly strong fundamentals make it a compelling investment for long-term investors, especially when you factor in how well it's been doing in the GLP-1 race. Mounjaro's sales rose by 125% in Q1, and Zepbound rose by 80%. This is with these drugs still being in their fairly early growth stages. And yet, they combined for nearly $13 billion in revenue this past quarter.

The only real drawback about Eli Lilly stock these days is that it isn't cheap. It trades at 39 times its trailing earnings. A premium is justifiable for the growth stock, given its impressive results; it's just a matter of how much is too much. By comparison, the average stock on the S&P 500 trades at 25 times its trailing earnings.

Viking Therapeutics doesn't have an approved drug just yet, but if it does, the stock could surge

At around $4 billion in market cap, Viking's valuation is a small fraction of Eli Lilly's. But that's also to be expected for a company that doesn't have any approved products and that doesn't generate any revenue today. It's a risky option.

Normally, I wouldn't consider this type of stock, but I believe that Viking is less of a risk than other similar pharma stocks, simply because of how well its GLP-1 drug, VK2735, has been doing in clinical trials. I'm optimistic that it could obtain approval, and if that happens, the stock could instantly skyrocket and potentially become an enticing acquisition target for a larger healthcare company.

VK2735 is in the midst of phase 3 trials for its subcutaneous version and expects to begin late-stage trials for the oral version later this year. Viking may not be far away from obtaining approval for VK2735, which, in earlier trials, showed that the subcutaneous version was able to help people lose up to 15% of their body weight, on average. While that may not be as high as the weight loss from Eli Lilly's products, it's not sheer weight loss that may be most important but overall tolerability, and thus, there is room for multiple types of drugs in the massive GLP-1 drug market, which is why there could still be strong demand for VK2735 if it obtains approval, as it may be a better fit for some patients.

Which stock should you buy?

Both of these GLP-1 stocks can be good buys, but if I were picking one, it would be Viking Therapeutics. Taking a modest position in the stock could be a good strategic move to make, to ensure you aren't investing heavily into a stock with a fair bit of risk.

However, this is what I'd consider to be a calculated risk. VK2735 is involved in multiple trials and has been making good progress. Obtaining even a single approval could be a game changer for the stock. It's not a guarantee, but if you're comfortable with the risk, I think it may be worth buying Viking's stock given the massive upside it may possess in the long run.

David Jagielski, CPA has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Eli Lilly. The Motley Fool recommends Viking Therapeutics. The Motley Fool has a disclosure policy.