Baking soda can be very harsh on the hair, but how harsh it is depends on the concentration you use and the porosity of your hair. Because baking soda is alkaline, it raises the cuticle of the hair shaft, making it rough, dry, and porous. The more baking soda you use per cup of water, the more alkaline the solution will be and the harsher it will be on your hair. Also if your hair is porous, it won't be able to tolerate as much baking soda. Many recipes I've seen on the internet are much too harsh for my hair, including the one on live curly live free. I use no more than 1 tsp of baking soda per cup of water.

A vinegar rinse is absolutely essential to do after a baking soda treatment. Hair is naturally acidic, so you need to restore the pH balance of your hair to smooth the cuticle back down. I use 1 tsp vinegar per cup of water. This amount has a pH of 4.5 and is safe to use every day.

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My hair is porous, medium thickness, good elasticity, medium density, 2c/3a, APL, dark brown with a silver lining. Biggest enemy: frizz!