Thank you for reaching out to us! Try Evivo for 21 days. If you're not satisfied, we'll give you a full refund, less the cost of shipping. Simply contact Customer Service within 21 days and include your Evivo order number and we'll take care of the rest. Our guarantee is available on new 1-month Starter Kits or 1-month Refills, first order only. Limited to one per customer.