Battle of the Colossal Women(2003)

Suzi's a nerdy scientist with a crush on Todd. But Todd's dating the dominating Liluth and doesn't even know Suzi is alive. So Suzi begins experimenting with a formula that will make her sexy and seductive. It works...too well! Suddenly 30 ft tall, she discovers new strength she never imagined possible. Liluth, jealous that this loser has such power, swallows down the rest of the formula. Soon she is huge and grabs up Todd to find Suzi. She does and they battle. But then they find themselves attracted to each other. And that's when the fun really begins!