Gainz Box Coupon: $7 Off Your First Month! Posted by Hello Subscription on November 12, 2019. Subscription Box Coupons & Deals Make the first comment! Hello Subscription independently researches and reviews the best subscriptions and products. Things you buy through our links may earn us a commission. Save for LaterGo to commentsNotification Gain[z] Box has a new sale! Get $7 off your first month! Just use the code PERKS. Valid to new subscribers only. Get $7 off at Gain[z] Box! Are you getting Gain[z] Box?