Why would you ever think about swallowing hair dye? And what benefits will you get if you really did? Hair dye contains ammonia and ammonia can cause severe burns and damage to your stomach and baby. If you swallow hair dye and the chemicals in it, you'll definitely poison yourself and your baby. Hydrogen peroxide can cause death if swallowed and hair dye does contain hydrogen peroxide. Please don't try it, it will NOT work, you know, it wont just magically apply itself on the the baby's scalp. I am not being mean or anything, just don't swallow hair dye, its very toxic. 😱plus, it has a very strong odor which can cause nausea and vomiting. If you swallow it you can vomit blood because ammonia will burn and make holes in r stomach causing the blood to get in. So yeah, probably a bad idea to swallow hair dye