Discount codes don't stack. If you have 57% off discount, they can't also use a "free shipping" coupon since Only one discount at a time can apply to a single order at the serotalin site.

Normally, one discount code is only applied for one offer. However, If the users put a vast of items in their cart, it is easy to use one coupon code to purchase items. It depends on serotalin's policy, you can contact serotalin via mail for your reference.

To avoid this problem, you should check out carefully serotalin promo code before that promo code could be expired, some promo codes are tied to a minimum purchase, a first-time purchase, or tied to geography, and other reasons.

Yes. Coupons for each Discount Event of serotalin will be collected here while being updated day by day. Sometimes, there will be deals not updated promptly but it's rare, we expect sympathy from you. 

All deals from Promotion Programs of serotalin are collected here. For each certain occasion, its coupons will be on the top of the coupon list, and surely they always come with an expiry date.

At the time of updating, serotalin has not applied Student Discount all year round yet. Check the official store and reach out to the customer support team to be clear.