Spectrum Labs guarantees our products. If used according to the directions, products will be effective delivering negative nicotine readings on nicotine pre-employment tests. If you test positive for nicotine on a pre-employment nicotine test we will refund your purchase price, up to the price listed on our website. Send proof of nicotine test failure, a copy of a state issued photo ID, product packaging or label along with instructions and proof of purchase to: Spectrum Labs, PO Box 8401, Cincinnati OH 45208 attn: Guarantee Dept. Please allow 6 - 8 weeks for processing.