Are weight loss drugs blockbusters?

The obesity market is expected to grow into a $54B market, but many questions remain, including the cost of $1,000-$1,500 a month and side effects, including nausea or diarrhea. After years of failed drugs, a new class of weight loss drugs reached the market last year — proving to be highly effective, but we don’t know about long-term side effects.

Obesity can lead to heart disease — one of the leading causes of death in the U.S. With nearly 40%of Americans over 20 years old being obese, the estimated cost of U.S. obesity was ~$173B in 2019.

A July 2022 phase 3 double-blind, randomized, controlled trial published in the New England Journal of Medicine found that 5, 10, or 15 mg doses of tirzepatide, administered weekly, led to “substantial and sustained” weight loss

Wall Street has high hopes for the industry, with Morgan Stanley expecting global obesity drug sales to reach $54B by 2030 — up from the $2.4B estimated sales this year. Two giants are expected to dominate the market:

  • Novo Nordisk received FDA approval for its weight loss drug last year.
  • Eli Lilly’s Tirzepatide received FDA approval to treat diabetes and, in phase three trials, helped obese people lose as much as 22.5% of their weight.

However, health insurers still see these drugs as “vanity drugs.”

There is no doubt that the long-term effects of obesity cost us a lot of money. So why aren’t insurers promoting weight loss drugs to their customers? The first reason is cost. These drugs can cost $1000-$2500 a month. The second is side effects of long-term use. Will, for example, patients need to be on these drugs for life, and if so, what are the risks?

Cost may be an essential consideration for prescribers. Many payers will not cover these off-label prescriptions unless the patient has diabetes. The maker of tirzepatide, Lilly, is currently offering coupons for the medication, but it’s not clear how long those will be available for a drug that must be taken long-term.

There are significant hurdles to widespread adoption and not just questions of cost and approval that every drug faces on its way to the public. Weight loss drugs have a checkered past. “If you look back in the history of obesity, drugs that have been approved have then been taken off the market,” says Dr. Spencer Nadolsky, a physician who runs the obesity program for telehealth provider Weekend Health. Dangerous amphetamines were used as appetite suppressants, and more recent drugs, like Fen-Phen, a weight loss drug widely used in the 1990s, caused heart problems, leading to an FDA ban. Safer weight loss drugs began reappearing in the 2000s, but their efficacy was often mild.

Wall Street smells the potential of huge profits and is applying pressure. Lilly is already debating whether to cobrand their drug: one for weight loss and one brand for people with diabetes. I analyzed social media and found that potential patients have concerns about the side effects and costs. Taking a drug for a specific time is one thing, but taking it for life is another barrier that patients may not be ready to overcome.