Demand for weight-loss drugs has exploded, with material differentiation among the players in the niche.
There's a clear leader, but that may not be the best investment option for you in 2026.
The introduction of GLP-1 weight-loss drugs by Novo Nordisk (NYSE: NVO) may have changed the pharmaceutical industry forever. Although there are drawbacks to taking GLP-1 drugs (such as muscle loss), they are viewed as a miracle drug by many who have struggled for years with obesity. That said, which company is the best investment? Here are three different ways to play the space in 2026.
Novo Nordisk was first to market, but Eli Lilly's (NYSE: LLY) GLP-1 shot proved more effective. And when Novo Nordisk faced production issues, the decision to choose Eli Lilly's Mounjaro and Zepbound over Novo Nordisk's Wagovy became even easier. The growth of Mounjaro and Zepbound has been nothing short of phenomenal, with Mounjaro's sales up 125% in the first quarter of 2026, and Zepbound up by 80%.
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Eli Lilly recently introduced a GLP-1 pill, but it has a different active ingredient, and uptake has been a bit sluggish (more on this below). Still, the strength of Mounjaro and Zepbound remains impressive, and investors have taken notice. If you prefer to stick with industry leaders, Eli Lilly could be the right choice for your portfolio. The one problem is that the stock is expensive, with a price-to-earnings ratio of 35x, as earnings appear to be catching up to the stock's lofty price.
Novo Nordisk was the first to market with a GLP-1 shot, and it was the first to market with a GLP-1 pill. Notably, the drug company's pill contains the same drug as the shot, so doctors and patients already have a lot of information about the pill to work off of. And it appears to be more effective than Eli Lilly's GLP-1 pill. Uptake for the Wagovy pill has been very strong and appears to be attracting new customers to weight-loss drugs.
The problem is that pricing pressures and patent expirations are expected to be significant headwinds for Novo Nordisk in the near term. But with the stock down 45% from its 52-week high, Novo Nordisk could be a strong turnaround opportunity in the GLP-1 space, given the long-term growth potential of GLP-1 drugs. The P/E is a far more appealing 10x, for those with a value focus.
If you are a real risk-taker, Viking Theraputics (NASDAQ: VKTX) is a money-losing pharma start-up with GLP-1 drugs in clinical trials. The stock has experienced dramatic price swings over the past year but has gone literally nowhere, up less than 1% as of this writing. However, the price swings suggest that a breakthrough would likely lead to a material share price advance. Only the most aggressive growth investors should probably consider this one.
If you are looking to invest in the GLP-1 space, the best balance of risk and reward is likely to be Novo Nordisk. However, Eli Lilly is the current leader in the niche, a position the company is using to diversify its drug pipeline. And for some investors, high-risk Viking Theraputics could be a wildcard that pays off.
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Reuben Gregg Brewer has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Eli Lilly. The Motley Fool recommends Novo Nordisk and Viking Therapeutics. The Motley Fool has a disclosure policy.