My go-to resource when I formulate products. Their ingredient database is extensive with comprehensive information and clear ratings. You can also search by product (for major brands) and get a complete picture of how healthy a product is as a whole.

They also have a comprehensive ingredient database that provides basic information - the function of the ingredient, irritancy factor and comedogenicity (its potential to clog pores). I like it when I just need a quick rundown of how it affects the skin.

My hands down, all time favorite source for high quality, organic herbs!

Pretty much the ONLY resource I trust for essential oil information. For over 40 years Robert Tisserand has been a leading expert on essential oils and aromatherapy. All of the Institutes information is backed by solid science verified through clinical trials and studies, with an emphasis on essential oil safety. Their blog is full of expert information you can trust.