Teddi Mellencamp is getting real about body image during her Stage 4 cancer battle -- revealing she actually asked for weight-loss meds while in the thick of it.

"The Real Housewives of Beverly Hills" alum said on her "Two Ts In A Pod" podcast that after packing on weight from steroids, she asked her doctor for GLP-1s ... but got shut down.

Teddi kept it light, joking about the mixed messages from her doctors, saying, "You tell me to live my best life ... but where are my GLP-1s?"

Jokes aside, it's been a brutal few years for Teddi. She was first diagnosed with melanoma, a type of skin cancer, in 2022 ... and underwent surgery for Stage 2.

She's had multiple surgeries since, including an emergency one earlier this year after the cancer spread to her brain. Teddi later revealed it had spread to her lungs.

The upside -- she says she's recovering well.