Gainz Box August 2018 Spoiler + Coupon! Posted by Hello Subscription on July 16, 2018. Subscription Box Spoilers / Gainz Box Spoilers Hello Subscription may earn compensation via links in this post. Read the full disclosure Save for Later Notification Gain[z] Box released the first spoilers of the August 2018 Gainz box! DEAL: Get 15% off your June box with coupon code GZ15. It’s a collaboration with Mattie Rogers. Here’s a sneak peek: Are you getting Gain[z] box this month?