Review title is Formaldehyde?! Not safe. 2 Stars ⭐ [SEP] After going over the ingredients in these products, the only two I would feel even remotely safe using would be this shampoo and conditioner. As a hair stylist, you do not want to use a product that contains formaldehyde and apply heat to it. You certainly do not want to use it every 6 weeks, as it's harmful to your health. It can cause breathing issues among other things. It's very hard to believe that I even saw actual formaldehyde on the back of this product, and so high up in the ingredients list.<br />Even hair stylist must wear protective gear, such as gloves, aprons, masks, and be trained how to safely work with this hazardous chemical. Salons must have adequate ventilation and follow strict protocols regarding blow dryer temperatures and monitor formaldehyde levels at all times when they provide Keratin Treatments containing formaldehyde because of the immediate and long term health dangers.This is something you cannot possibly do at home.<br />Also, the pretreatment that you add to the shampoo is extremely strong and stripping to your hair. When they say add just a little, no one knows what that means. That particular product, or the two main ingredients, should only be a small percentage of the product you're adding it to. I don't think you can mix this properly at home without causing damage to your hair and/or your skin.<br />I "might" use the shampoo and conditioner, but I will not touch the pre-treatment nor will I touch the DIY home keratin treatment. Over the course of a few treatments, I can see this product going really awry for some people. They will end up with damaged hair and possibly other problems. It is not safe. I absolutely would not recommend it!