1. Before purchasing, check the production license and relevant certification marks of the product to ensure that the product is legal and compliant.
2. Don't trust the publicity and promotion of the merchants, carefully check the composition and efficacy of the products and compare them with other brands.
3. If you have any discomfort, you should stop using it immediately and consult a doctor.
In short, it is necessary to be vigilant when buying Jiuheitang hair dye, pay attention to choosing regular channels to buy, and pay attention to the usage and precautions of the product.