Eli Lilly just launched Foundayo, a $149-per-month weight loss pill that analysts say could become the biggest pharmaceutical product of the decade. But before you rush to buy the stock, let's talk about what they're not shouting from the rooftops.

The FDA approved Foundayo on April 1st, making it the second oral GLP-1 weight loss drug on the market after Novo Nordisk's Wegovy. The pitch is simple: no more weekly injections, no meal restrictions, just pop a pill and go about your day. Dave Ricks, Lilly's CEO, says it "fits into your daily routine" like any other medication.

Here's what Wall Street is getting excited about: analysts are projecting $101 billion in peak revenue. That's not a typo. If even half that projection materializes, we're looking at one of the most successful drug launches in history.

But here's what they're not telling you.

First, the efficacy. In clinical trials, Foundayo users lost 12.4% of their body weight at the highest dose over 72 weeks. That sounds impressive until you compare it to the injectable versions. Wegovy and Zepbound—the needle versions—deliver significantly better results. Dr. Jody Dushay, a Harvard endocrinologist, put it bluntly: "12% is weak compared to what you're going to see with Wegovy and Zepbound."

Translation: you're paying for convenience, not superior performance.

Second, the insurance question. The $149 price tag assumes you're paying out of pocket. Under the current administration's plans, Medicare might cover it with copays as low as $50 per month starting this summer. But private insurance coverage remains a giant question mark. If insurers balk at the cost, that $101 billion projection starts to look optimistic.

Third, the competition is coming. Lilly itself has retatrutide in development, which early data suggests delivers better weight loss than Foundayo. Novo Nordisk isn't sitting still either. The first-mover advantage in oral GLP-1s is real, but it won't last forever.

So what does this mean for you?

If you're a patient, Foundayo is a genuine breakthrough. Anything that makes weight loss treatment more accessible and convenient is good news. But if you're an investor looking at Eli Lilly stock, you need to ask yourself: is the $101 billion opportunity already baked into the current valuation?

Lilly's stock has been on a tear for the past two years, largely on the promise of its obesity franchise. The company is now trading at a premium multiple compared to other big pharma names. That doesn't mean it's expensive—maybe the GLP-1 revolution really does justify it. But it does mean there's less room for error.

Here's my take: this is a real product with real demand solving a real problem. But Wall Street has a habit of pricing in the best-case scenario and calling it the base case. The insurance coverage question, the efficacy gap versus injectables, and the pipeline competition all represent risks that aren't getting enough airtime.

If you own the stock, I'm not saying sell. But if you're thinking about buying here, make sure you're not just buying the hype. Ask yourself what happens if peak sales come in at $50 billion instead of $101 billion. Ask what happens if insurance coverage is slower to materialize than bulls expect. Ask what the stock does when retatrutide data comes out and shows Lilly's own next-gen drug makes Foundayo look obsolete.

The best products don't always make the best investments—especially when everyone already knows they're the best products.