Unlike scores of people who scrambled for the blockbuster drugs Ozempic and Wegovy to lose weight in recent years, Danielle Griffin had no trouble getting them. The 38-year-old information technology worker from New Mexico had a prescription. Her pharmacy had the drugs in stock.

And her covered all but $25 to $50 of the monthly cost. For Griffin, the hardest part of using the new drugs wasn’t access. It was finding out that the didn’t really work for her.

“I have been on Wegovy for a year and a half and have only lost 13 pounds,” said Griffin, who watches her diet, drinks plenty of water and exercises regularly. “I’ve done everything right with no success. It’s discouraging.

” In clinical trials, most participants taking Wegovy or Mounjaro to treat obesity lost an average of 15% to 22% of their body weight — up to 50 pounds or more in many cases. But roughly 10% to 15% of patients in those trials were “nonresponders” who lost less than 5% of their body weight. Now that millions of people have used the drugs, several obesity experts told The Associated Press that perhaps 20% of patients — as many as 1 in 5 — may not respond well to the medications.

It’s a little-known consequence of the obesity drug boom, according to doctors who caution eager patients not to expect one-size-fits-all results. “It’s all about explaining that different people have different responses,” said Dr. Fatima Cody Stanford, an obesity expert at Massachusetts General Hosp.