(NEXSTAR) – The diabetes drug Semaglutide has sparked a weight loss craze, as people realized it can be used to shed pounds quickly when prescribed off-label.

Semaglutide is better known by the brand names it’s marketed under, like Ozempic and Wegovy. Tirzepatide, marketed as Mounjaro, has gotten a lot of buzz for the same reasons. But enthusiasm for the drugs has led to a short supply, along with patients reporting unexpected side effects.

One such side effect has been described as “Ozempic face.” The rapid weight loss can leave some patients’ faces looking hollowed out, sagging and rapidly aged.

“When it comes to facial aging, fat is typically more friend than foe,” plastic surgeon Dr. Oren Tepper told the New York Times. “Weight loss may turn back your biological age, but it tends to turn your facial clock forward.”

“One of the most common things I notice with any form of weight loss in middle-aged and older patients is we don’t all lose it in the areas we want,” Dr. Paul Jarrod Frank said in an interview with TODAY. “When we get older, definitely the facial volume changes and shifts around. But when you lose weight so acutely and quickly, you see more of a global facial wasting.”

That “facial wasting” is what can make a person suddenly look much older.

To treat so-called “Ozempic face,” some patients are turning to another medical procedure: injecting dermal fillers to make their faces look fuller.

Dr. Dhaval Bhanusali told the Times he’s seen an increase in patients looking for fillers after dramatic Ozempic or Mounjaro-driven weight loss. “Generally, it’s people in their 40s and 50s who are losing significant amounts of weight and are concerned about facial aging and sagging that occurs as a result.”

Ozempic and Mounjaro were originally used to treat type 2 diabetes. The injections are shown to improve blood sugar levels and heart function, but doctors have more recently started prescribing them to help patients lose weight.

The drugs both have more serious side effects, as well, including possible pancreas inflammation, vision changes, low blood sugar, problems with the kidneys and gallbladder, and a higher risk of developing thyroid cancer.

The drugs aren’t cheap, either. Unless you can get it covered under insurance, they run about $1,000 for a one-month supply.