The actress -- best known for playing Suzanne Sugarbaker on "Designing Women" -- stopped by the 'Glamorous Trash' podcast and opened up about how the scrutiny over her weight led her to drug use.

Delta said she was first prescribed weight-loss pills while in acting school in London, but later learned the prescription was illegal in the States -- so, she had someone get her similar pills while she starred in "Filthy Rich" between 1982 and 1983.

The pills, which she called "Black Beauties," helped curb her appetite during the day, but she says she eventually built up a tolerance.

That's when a coworker suggested she try methamphetamine ... and she did!!!

She added ... "[They told me], 'You chop it up. You snort.' I said, I don't want to snort it. So I put it in cranberry juice and [drank] it … and wouldn't eat for 5 days."

Despite her attempts to lose weight, Delta recalled still being criticized for her body, which greatly impacted her mental health ... and even led to her early exit from 'DW.'

While Delta's admission might seem shocking, she isn't the first celeb to seek drug assistance in order to achieve a body transformation.

The difference is ... now A-listers get those drugs prescribed, as more and more openly turn to weight-loss meds like Wegovy and Ozempic.

Oprah, Amy Schumer, Tracy Morgan, Sharon Osbourne and Chelsea Handler have all admitted to using weight-loss drugs.