... the effect for at least 3 months 4.Allergy free, safe,green product 5.OEM [Ingredient] ... sensitive to aniline hair dye, no need to allergy testing when using this product. However, if sensitive ... food, Chinese medicine natural substances, you need to do allergy testing before use, smudge 1#, 2#, 3# separately ... once opening, if not, you must squeeze excess air and close the bottle cap, if with long hair ...