Loosens and straightens locks like a "liquid flatiron," even when they're exposed to high humidity. It's available in two formulas to ensure you get the right amount of power ($49; ulta.com
"This has a variety of plant oils and butters to deep-condition hairas well as azurite, a mineral that helps transfer heat more efficiently from blow-dryer and flatironso the treatment doesn't take as long," says Hammer.OUR VERDICT
We loved that we could wash our hair within 24 hours, since many treatments require that the keratin stays on for 48. Afterward, our hair wasn't stick-straight, but it did feel sleeker; it even relaxed those tricky wavy strands around the hairline.