Just For Men Shampoo-In-Color Sandy Blond H-10Just For Men Shampoo-In-Color Sandy Blond H-10. Just For Men targets only the gray hair. Replaces it with subtle tones that match your own natural color in 5 easy minutes. The ammonia-free formula lasts up to 6 weeks, until the gray grows out. IMPORTANT: READ AND FOLLOW THE SKIN ALLERGY PATCH (ALERT) TEST INSTRUCTIONS AND SAFETY WARNINGS ON PACKAGE BEFORE YOU USE THIS PRODUCT. YOU MUST PERFORM THIS SKIN ALLERGY PATCH (ALERT) TEST 48 HOURS BEFORE EACH USE EVEN IF YOU HAVE ALREADY USED THIS OR ANOTHER HAIRCOLOUR PRODUCT WITHOUT AN ADVERSE REACTION. Allergic reactions (itching, burning, redness, swelling, skin abrasions, eruptions or irritation) to permanent haircolour, including this product, can occur and in rare instances be severe. If you ever experienced any of those symptoms while using this product, stop using haircolouring products until you consult a doctor, as these are signs that you may have developed an allergy. • You MUST do this test 48 hours ahead of EACH and EVERY use in order to minimize the risk of an allergic reaction. This test is not a guarantee of avoiding future allergic reactions. • For some users, frequent use of haircolouring products can increase the risk of allergic reactions. • This test represents an important precaution. However, be aware that even if a test has been carried out, you may still experience an allergic reaction when you use this product.