The singer, 21, looked healthy and raring to go at a press conference at the O2 arena in London Tuesday as she prepared for the restart of her Bangerz tour.
Crediting vitamins, yoga and honey with getting well again, she says that she "kind of took the natural route" when conventional meds weren't working.
"I'm the poster child for good health," she says, adding she'd been "connected to an IV for the last two weeks. I'm going to go off!"
"You have no idea how ready I am. There is nothing I would rather not do than lay in a bed for two weeks. It was the most miserable two weeks of my life," says Cyrus, dressed in red leather pants, a short denim jacket and black rockabilly shoes.
When discussing her illness, she referred to online rumors.
"I didn't have a drug overdose. I took some sh––y antibiotics that a doctor gave me for a sinus infection and I had a reaction."
She then had a setback when she was packing for the tour and had to reschedule additional dates.
But now she says she feels "better than ever."
"I'm on this crazy vitamin rush and crazy honey and lavender," she says. "I learned a lot about taking care of yourself."
"I'm probably the only one on this tour who doesn't drink or smoke before a show, as I take this really seriously," the "Wrecking Ball" singer says. "It's almost like being an athlete being up here, because if someone was f––ed up, they definitely couldn't do my show."
Cyrus promises some tunes from British artists like the Arctic Monkeys and Coldplay in her London performance. And there'll be some country, care of her godmother, Dolly Parton.
"I don't know how Dolly Parton goes over here, but I'm doing a Dolly song, so that could go one way or another," she said. "Everyone likes Dolly! Hopefully everyone will sing along."
It was also announced on Tuesday that Cyrus will perform at the 2014 Billboard Music Awards, airing May 18 at 8 p.m. ET on ABC.