Daily obesity tablets are accelerating the shift away from injections and opening a much larger market for drugmakers.
Oral versions of GLP-1 treatments reduce appetite like the jabs but are easier to take, cheaper and require no refrigeration.
Analysts expect these advantages to attract new patients who previously avoided treatment.
Novo Nordisk launched the first weight-loss pill form of Wegovy in the US, and early demand has been strong.
Rival Eli Lilly plans to follow with its own tablet, intensifying competition in a market forecast to reach about $200bn within a decade.
Patients switching from injections report more consistent appetite control and lower costs, especially when insurance coverage changes.
Doctors say tablets are drawing both new users and former injection patients back into treatment.
Injectable drugs still produce greater weight loss, so people with severe obesity are likely to stay on them.
Pills are expected to appeal mainly to those who are overweight or mildly obese.
Regulators in the UK are reviewing the new treatments while demand rises globally.
Researchers believe falling prices, broader insurance coverage and more drug options will push these medicines further into the mainstream.
